TRAMADOL: 75,664 Adverse Event Reports & Safety Profile

Tramadol Hydrochloride Extended-Release Capsules are an opioid agonist in an extended-release oral formulation. The chemical name for tramadol hydrochloride USP is (±) cis- 2-[(dimethylamino)methyl]-1-(3-methoxyphenyl) cyclohexanol hydrochloride. Its structural formula is: Figure 1 C 16 H 25 NO 2 ∙ HCl The molecular weight of tramadol hydrochloride USP is 299.8. It is a white, bitter, crystalline and odorless powder that is readily soluble in water and ethanol and has a pKa of 9.41. The n-octanol/water log partition coefficient (logP) is 1.35 at pH 7.

Tramadol Hydrochloride

Extended-Release Capsules contain a total dose of tramadol hydrochloride 100, 200, and 300 mg in a combination of immediate-release and extended-release components.

Dosage

Immediate-release Extended-release 100 mg 25 mg 75 mg 200 mg 50 mg 150 mg 300 mg 50 mg 250 mg Tramadol Hydrochloride Extended-Release Capsules are white in color. Inactive ingredients include gelatin, titanium dioxide, shellac, FD & C Blue #2 aluminum lake (E132) (100 and 200 mg capsules), D & C Red #7 calcium lake (E180) (200 and 300 mg capsules), D & C Yellow #10 aluminum lake (300 mg capsule), lactose monohydrate 200 mesh, microcrystalline cellulose, povidone K30, corn starch, sodium starch glycolate, magnesium stearate, sucrose stearate, hypromellose, talc, polysorbate 80, Eudragit NE 30D, and simethicone emulsion.

Chemical

Structure

AND USAGE Tramadol hydrochloride extended-release tablets are indicated for the management of severe and persistent pain that requires an extended treatment period with a daily opioid analgesic and for which alternative treatment options are inadequate. Limitations of Use Because of the risks of addiction, abuse, and misuse with opioids, which can occur at any dosages or duration, and because of the greater risks of overdose and death with extended-release/long-acting opioid formulations [see Warnings and Precautions (5.1)] , reserve tramadol hydrochloride extended-release tablets for use in patients for whom alternative treatment options (e.g., non-opioid analgesics or immediate-release opioids) are ineffective, not tolerated, or would be otherwise inadequate to provide sufficient management of pain. Tramadol hydrochloride extended-release tablets are not indicated as an as-needed (prn) analgesic. Tramadol hydrochloride extended-release tablets are an opioid agonist indicated for the management of severe and persistent pain that requires an extended treatment period with a daily opioid analgesic and for which alternative treatment options are inadequate. (1) Limitations of Use Because of the risks of addiction, abuse, and misuse with opioids, which can occur at any dosages or duration, and because of the greater risks of overdose and death with extended-release/long-acting opioid formulations, reserve tramadol hydrochloride extended-release tablets for use in patients for whom alternative treatment options (e.g., non-opioid analgesics or immediate-release opioids) are ineffective, not tolerated, or would be otherwise inadequate to provide sufficient management of pain. (1) Tramadol hydrochloride extended-release tablets are not indicated as an as-needed (prn) analgesic. (1)

AND ADMINISTRATION Tramadol hydrochloride extended-release tablets should be prescribed only by healthcare providers knowledgeable about the use of extended-release/long-acting opioids and how to mitigate the associated risks. ( 2.1 ) Use the lowest effective dosage for the shortest duration of time consistent with individual patient treatment goals. Reserve titration to higher doses of tramadol hydrochloride extended-release tablets for patients in whom lower doses are insufficiently effective and in whom the expected benefits of using a higher dose opioid clearly outweigh the substantial risks. ( 2.1 , 5 ) Initiate the dosing regimen for each patient individually, taking into account the patient's underlying cause and severity of pain, prior analgesic treatment and response, and risk factors for addiction, abuse, and misuse. ( 2.1 , 5.1 ) Respiratory depression can occur at any time during opioid therapy, especially when initiating and following dosage increases with tramadol hydrochloride extended-release tablets. Consider this risk when selecting an initial dose and when making dose adjustments. ( 2.1 , 5.2 ) Discuss opioid overdose reversal agents and options for acquiring them with the patient and/or caregiver, both when initiating and renewing treatment with tramadol hydrochloride extended-release tablets, especially if the patient has additional risk factors for overdose, or close contacts at risk for exposure and overdose. ( 2.2 , 5.1 , 5.2 , 5.3 ) Tramadol hydrochloride extended-release tablets should be taken once daily, at approximately the same time every day. ( 2.3 ) For patients currently on tramadol IR, calculate total 24-hr IR dose, and initiate tramadol hydrochloride extended-release tablets at a dose rounded down to next lower 100 mg increment; then adjust dose according to need and tolerance. See full prescribing information for instructions on conversion, titration, and maintenance of therapy. ( 2.3 , 2.4 ) For patients converting from other opioid analgesics, discontinue all opioid analgesics other than as needed for breakthrough pain and initiate tramadol hydrochloride extended-release tablets at a dose of 100 mg once daily, then titrate up by 100 mg increments every 5 days according to need and tolerance. ( 2.3 , 2.4 ) Do not exceed a daily dose of 300 mg tramadol. Do not use with other tramadol products. ( 2.4 ) Periodically reassess patients receiving tramadol hydrochloride extended-release tablets to evaluate the continued need for opioid analgesics to maintain pain control, for the signs or symptoms of adverse reactions, and for the development of addiction, abuse, or misuse. ( 2.4 ) Do not rapidly reduce or abruptly discontinue tramadol hydrochloride extended-release tablets in a physically dependent patient because rapid reduction or abrupt discontinuation of opioid analgesics has resulted in serious withdrawal symptoms, uncontrolled pain, and suicide. ( 2.5 , 5.18 ) Discuss opioid overdose reversal agents and options for acquiring them with the patient and/or caregiver, both when initiating and renewing treatment with tramadol hydrochloride extended-release tablets, especially if the patient has additional risk factors for overdose, or close contacts at risk for exposure and overdose. [ 2.2 , 5.2 , 5.3 ]

2.1 Important Dosage and Administration Instructions Tramadol hydrochloride extended-release tablets should be prescribed only by healthcare professionals who are knowledgeable about the use of extended-release/long-acting opioids and how to mitigate the associated risks. Do not use tramadol hydrochloride extended-release tablets concomitantly with other tramadol products <span class="opacity-50 text-xs">[see Warnings and Precautions ( 5.3 ), ( 5.15 )]</span> . Do not administer tramadol hydrochloride extended-release tablets at a dose exceeding 300 mg per day. Use the lowest effective dosage for the shortest duration of time consistent with individual patient treatment goals [ see Warnings and Precautions ( 5.5 ) ]. Because the risk of overdose increases as opioid doses increase, reserve titration to higher doses of tramadol hydrochloride extended-release tablets for patients in whom lower doses are insufficiently effective and in whom the expected benefits of using a higher dose opioid clearly outweigh the substantial risks. Initiate the dosing regimen for each patient individually, taking into account the patient&apos;s underlying cause and severity of pain, prior analgesic treatment and response, and risk factors for addiction, abuse, and misuse <span class="opacity-50 text-xs">[see Warnings and Precautions ( 5.1 )]</span> Respiratory depression can occur at any time during opioid therapy, especially when initiating and following dosage increases with tramadol hydrochloride extended-release tablets. Consider this risk when selecting an initial dose and when making dose adjustments [ see Warnings and Precautions ( 5 ) ]. Tramadol hydrochloride extended-release tablets should be taken once daily, at approximately the same time every day. Instruct patients to swallow tramadol hydrochloride extended-release tablets whole <span class="opacity-50 text-xs">[see Patient Counseling Information ( 17 )]</span> , and to take it with liquid. Crushing, chewing, splitting, or dissolving tramadol hydrochloride extended-release tablets will result in uncontrolled delivery of tramadol and can lead to overdose or death <span class="opacity-50 text-xs">[see Warnings and Precautions ( 5.1 )]</span> . Tramadol hydrochloride extended-release tablets may be taken without regard to food, It is recommended that tramadol hydrochloride extended-release tablets be taken in a consistent manner <span class="opacity-50 text-xs">[see Clinical Pharmacology ( 12.3 )]</span> .

2.2 Patient Access to an Opioid Overdose Reversal Agent for the Emergency Treatment of Opioid Overdose Inform patients and caregivers about opioid overdose reversal agents (e.g., naloxone, nalmefene). Discuss the importance of having access to an opioid overdose reversal agent, especially if the patient has risk factors for overdose (e.g., concomitant use of CNS depressants, a history of opioid use disorder, or prior opioid overdose) or if there are household members (including children) or other close contacts at risk for accidental ingestion or opioid overdose. The presence of risk factors for overdose should not prevent the proper management of pain in any given patient <span class="opacity-50 text-xs">[see Warnings and Precautions ( 5.1 , 5.2 , 5.7 ]</span>. Discuss the options for obtaining an opioid overdose reversal agent (e.g., prescription, over-the counter, or as part of a community-based program) <span class="opacity-50 text-xs">[see Warnings and Precautions (5.2) ]</span>. There are important differences among the opioid overdose reversal agents, such as route of administration, product strength, approved patient age range, and pharmacokinetics. Be familiar with these differences, as outlined in the approved labeling for those products, prior to recommending or prescribing such an agent.

2.3 Initial Dosage It is safer to underestimate a patient&apos;s 24-hour tramadol requirements and provide rescue medication (e.g., immediate-release opioid) than to overestimate the 24-hour tramadol dosage and manage an adverse reaction due to an overdose. While useful tables of opioid equivalents are readily available, there is inter-patient variability in the potency of opioid drugs and opioid formulations. Frequently reevaluate patients for signs and symptoms of opioid withdrawal and for signs of oversedation/toxicity after converting patients to Tramadol Hydrochloride Extended-Release Tablets. Use of Tramadol Hydrochloride Extended-Release Tablets The initial dose of tramadol hydrochloride extended-release tablets is 100 mg once daily.

Patients

Currently on Tramadol Immediate-Release (IR)

Products

Calculate the 24-hour tramadol IR dose and initiate a total daily dose of tramadol hydrochloride extended-release tablets rounded down to the next lower 100 mg increment. The dose may subsequently be individualized according to patient need. Due to limitations in flexibility of dose selection with tramadol hydrochloride extended-release tablets, some patients maintained on tramadol IR products may not be able to convert to tramadol hydrochloride extended-release tablets. Conversion from Other Opioid Analgesics to Tramadol Hydrochloride Extended-Release Tablets When tramadol hydrochloride extended-release tablets therapy is initiated, discontinue all opioid analgesics other than those used on an as needed basis for breakthrough pain when appropriate. There are no established conversion ratios for conversion from other opioids to tramadol hydrochloride extended-release tablets defined by clinical trials. Initiate dosing using tramadol hydrochloride extended-release tablets 100 mg once a day.

2.4 Titration and Maintenance of Therapy Individually titrate tramadol hydrochloride extended-release tablets by 100 mg every five days to a dose that provides adequate analgesia and minimizes adverse reactions. The maximum daily dose of tramadol hydrochloride extended-release tablets is 300 mg per day. Continually reevaluate patients receiving tramadol hydrochloride extended-release tablets to assess the maintenance of pain control, signs and symptoms of opioids withdrawal and other adverse reactions, as well as to reassess for the development of addiction, abuse, or misuse <span class="opacity-50 text-xs">[see Warnings and Withdrawal ( 5.1 , 5.18 )]</span> . Frequent communication is important among the prescriber, other members of the healthcare team, the patient, and the caregiver/family during periods of changing analgesic requirements, including initial titration. During use of opioid therapy for an extended period of time, periodically reassess the continued need for the use of opioid analgesics. Patients who experience breakthrough pain may require a dosage adjustment of tramadol hydrochloride extended-release tablets, or may need rescue medication with an appropriate dose of an immediate-release analgesic. If the level of pain increases after dosage stabilization, attempt to identify the source of increased pain before increasing the tramadol hydrochloride extended-release tablets dosage. If after increasing the dosage, unacceptable opioid-related adverse reactions are observed (including an increase in pain after dosage increase), consider reducing the dosage <span class="opacity-50 text-xs">[see Warnings and Precautions ( 5 )]</span> . Adjust the dosage to obtain an appropriate balance between management of pain and opioid-related adverse reactions.

2.5 Safe Reduction or Discontinuation Of Tramadol Hydrochloride Extended-Release Tablets Do not rapidly reduce or abruptly discontinue tramadol hydrochloride extended-release tablets in patients who may be physically dependent on opioids. Rapid reduction or abrupt discontinuation of opioid analgesics in patients who are physically dependent on opioids has resulted in serious withdrawal symptoms, uncontrolled pain, and suicide. Rapid reduction or abrupt discontinuation has also been associated with attempts to find other sources of opioid analgesics, which may be confused with drug-seeking for abuse. Patients may also attempt to treat their pain or withdrawal symptoms with illicit opioids, such as heroin, and other substances. When a decision has been made to decrease the dose or discontinue therapy in an opioid-dependent patient taking tramadol hydrochloride extended-release tablets, there are a variety of factors that should be considered, including the total daily dose of opioid (including tramadol hydrochloride extended-release tablets) the patient has been taking, the duration of treatment, the type of pain being treated, and the physical and psychological attributes of the patient. It is important to ensure ongoing care of the patient and to agree on an appropriate tapering schedule and follow-up plan so that patient and provider goals and expectations are clear and realistic. When opioid analgesics are being discontinued due to a suspected substance use disorder, evaluate and treat the patient, or refer for evaluation and treatment of the substance use disorder. Treatment should include evidence-based approaches, such as medication assisted treatment of opioid use disorder. Complex patients with co-morbid pain and substance use disorders may benefit from referral to a specialist. There are no standard opioid tapering schedules that are suitable for all patients. Good clinical practice dictates a patient-specific plan to taper the dose of the opioid gradually. For patients on tramadol hydrochloride extended-release tablets who are physically opioid-dependent, initiate the taper by a small enough increment (e.g., no greater than 10% to 25% of the total daily dose) to avoid withdrawal symptoms, and proceed with dose-lowering at an interval of every 2 to 4 weeks. Patients who have been taking opioids for briefer periods of time may tolerate a more rapid taper. It may be necessary to provide the patient with lower dosage strengths to accomplish a successful taper. Reassess the patient frequently to manage pain and withdrawal symptoms, should they emerge. Common withdrawal symptoms include restlessness, lacrimation, rhinorrhea, yawning, perspiration, chills, myalgia, and mydriasis. Other signs and symptoms also may develop, including irritability, anxiety, backache, joint pain, weakness, abdominal cramps, insomnia, nausea, anorexia, vomiting, diarrhea, or increased blood pressure, respiratory rate, or heart rate. If withdrawal symptoms arise, it may be necessary to pause the taper for a period of time or raise the dose of the opioid analgesic to the previous dose, and then proceed with a slower taper. In addition, evaluate patients for any changes in mood, emergence of suicidal thoughts, or use of other substances. When managing patients taking opioid analgesics, particularly those who have been treated for an extended period of time and/or with high doses for chronic pain, ensure that a multimodal approach to pain management, including mental health support (if needed), is in place prior to initiating an opioid analgesic taper. A multimodal approach to pain management may optimize the treatment of chronic pain, as well as assist with the successful tapering of the opioid analgesic <span class="opacity-50 text-xs">[see Warnings and Precautions ( 5.17 ), Drug Abuse and Dependence ( 9.3 )]</span>.

Tramadol Hydrochloride Tablets, USP are contraindicated for:

• all children younger than 12 years of age [see Warnings and Precautions (5.4) ].
• post-operative management in children younger than 18 years of age following tonsillectomy and/or adenoidectomy [see Warnings and Precautions (5.4) ].

Tramadol Hydrochloride

Tablets, USP are also contraindicated in patients with:

• Significant respiratory depression [see Error! Hyperlink reference not valid. ].
• Acute or severe bronchial asthma in an unmonitored setting or in the absence of resuscitative equipment [see Error! Hyperlink reference not valid. ].
• Known or suspected gastrointestinal obstruction, including paralytic ileus [see Error! Hyperlink reference not valid. ].
• Hypersensitivity to tramadol, any other component of this product or opioids [see Error! Hyperlink reference not valid. ].
• Concurrent use of monoamine oxidase inhibitors (MAOIs) or use within the last 14 days [see Error! Hyperlink reference not valid. ].
• Children younger than 12 years of age ( 4) .
• Post-operative management in children younger than 18 years of age following tonsillectomy and/or adenoidectomy ( 4) .
• Significant respiratory depression ( 4) .
• Acute or severe bronchial asthma in an unmonitored setting or in the absence of resuscitative equipment ( 4) .
• Known or suspected gastrointestinal obstruction, including paralytic ileus ( 4) .
• Hypersensitivity to tramadol, any other component of this product or opioids ( 4) .
• Concurrent use of monoamine oxidase inhibitors (MAOIs) or use of MAOIs within the last 14 days ( 4) .

ADVERSE REACTIONS The following serious adverse reactions are described, or described in greater detail, in other sections: Addiction, Abuse, and Misuse (see WARNINGS ) Life-Threatening Respiratory Depression (see WARNINGS ) Ultra-Rapid Metabolism of Tramadol and Other Risk Factors for Life-Threatening Respiratory Depression in Children (see WARNINGS )

Neonatal Opioid Withdrawal

Syndrome (see WARNINGS ) Interactions with Benzodiazepines or Other CNS Depressants (see WARNINGS ) Opioid-Induced Hyperalgesia and Allodynia (see WARNINGS )

Serotonin

Syndrome (see WARNINGS ) Seizures (see WARNINGS ) Suicide (see WARNINGS )

Adrenal

Insufficiency (see WARNINGS )

Severe

Hypotension (see WARNINGS )

Gastrointestinal Adverse

Reactions (see WARNINGS )

Hypersensitivity

Reactions (see WARNINGS ) Withdrawal (see WARNINGS )

Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. Tramadol hydrochloride extended-release tablets were administered to a total of 2707 subjects (2406 patients and 301 healthy volunteers) during clinical studies, including four randomized double-blind studies (treatment ≥ 12 weeks) and two open-label long-term studies (treatment up to 12 months) in patients with moderate to severe pain due to osteoarthritis of the knee. A total of 844 patients were exposed to tramadol hydrochloride extended-release tablets for 12 weeks, 493 patients for 6 months and 243 patients for 12 months. Treatment emergent adverse events increased with dose from 100 mg to 300 mg in the three twelve-week, randomized, double-blind, placebo-controlled studies (Table 2).

Table

2. Percentage of Patients with Incidence of Adverse Events ≥ 2% from Three 12-week Placebo-Controlled Studies (MDT3-002, MDT3-003 and MDT3-005) ADVERSE EVENTS (MEDRA Preferred Terms)

Tramadol Hydrochloride

Extended-Release Tablets Placebo 100 mg 200 mg 300 mg Total * N=216 N=311 N=530 N=1095 N=668 Nausea 28 (13%) 42 (14%) 76 (14%) 179 (16%) 37 (6%)

Constipation

21 (10%) 36 (12%) 52 (10%) 140 (13%) 26 (4%)

Dizziness

16 (7%) 28 (9%) 52 (10%) 106 (10%) 18 (3%)

Somnolence

11 (5%) 22 (7%) 23 (4%) 77 (7%) 12 (2%)

Vomiting

7 (3%) 16 (5%) 31 (6%) 58 (5%) 4 (1%)

Pruritus

9 (4%) 15 (5%) 18 (3%) 51 (5%) 7 (1%)

Headache

10 (5%) 9 (3%) 15 (3%) 41 (4%) 21 (3%) Sweating increased 1 (0%) 9 (3%) 14 (3%) 35 (3%) 5 (1%) Dry mouth 7 (3%) 13 (4%) 6 (1%) 32 (3%) 8 (1%)

Fatigue

6 (3%) 7 (2%) 9 (2%) 26 (2%) 6 (1%)

Anorexia

4 (2%) 4 (1%) 10 (2%) 25 (2%) 2 (0%)

Vertigo

2 (1%) 3 (1%) 6 (1%) 21 (2%) 3 (0%)

Insomnia

2 (1%) 6 (2%) 9 (2%) 18 (2%) 8 (1%) *Due to the difference in study design of MDT3-005, only the results of the double-blind phase of the study are presented and the dose specific results include maintenance period data only. The majority of patients who experienced the most common adverse events (≥5%) reported mild to moderate symptoms. Less than 3% of adverse events were rated as severe. Overall, onset of these adverse events usually occurred within the first two weeks of treatment. Adverse reactions with an incidence of 1.0% to <5.0% Ear and labyrinth disorders: vertigo Gastrointestinal disorders: abdominal pain, diarrhea, dry mouth, dyspepsia, upper abdominal pain General disorders : fatigue, weakness Investigations: weight decreased Metabolism and nutrition disorders : anorexia Musculoskeletal and connective tissue disorders: arthralgia Nervous system disorders : headache, tremor Psychiatric disorders : anxiety, insomnia Skin and subcutaneous tissue disorders : pruritus, sweating increased Vascular disorders: hot flushes Adverse reactions with an incidence of <1.0% Blood and lymphatic system disorders: anemia, thrombocytopenia Cardiac disorders : bradycardia Eye disorders: blurred vision, visual disturbance Gastrointestinal disorders : abdominal discomfort, abdominal distension, abdominal tenderness, change in bowel habit, constipation aggravated, diverticulitis, diverticulum, dyspepsia aggravated, dysphagia, fecal impaction, gastric irritation, gastritis, gastrointestinal hemorrhage, gastrointestinal irritation, gastro-esophageal reflux disease, lower abdominal pain, pancreatitis aggravated, rectal hemorrhage, rectal prolapse, retching General disorders : asthenia, malaise Hepatobiliary disorders: biliary tract disorder, cholelithiasis Immune system disorders: hypersensitivity Investigations : alanine aminotransferase decreased, alanine aminotransferase increased, aspartate aminotransferase decreased, aspartate aminotransferase increased, blood amylase increased, blood creatinine increased, blood in stool, blood potassium abnormal, blood pressure increased gamma glutamyltransferase increased Metabolism and nutrition disorders : appetite decreased, dehydration Nervous system disorders : ataxia, disturbance in attention, dysarthria, gait abnormal, headache aggravated, mental impairment, sedation, seizure, sleep apnea syndrome, syncope, tremor Psychiatric disorders : abnormal behavior, agitation, anxiety, confusion, depression, emotional disturbance, euphoric mood, indifference, irritability, libido decreased, nervousness, sleep disorder Renal and urinary disorders : difficulty in micturition, urinary hesitation, urinary retention Reproductive system and breast disorders : erectile dysfunction, sexual dysfunction Respiratory, thoracic and mediastinal disorders : dyspnea Skin and subcutaneous tissue disorders : allergic dermatitis, cold sweat, dermatitis, night sweats, pallor, generalized pruritus, urticaria Vascular disorders : flushing, hypertension, hypotension, orthostatic hypotension Postmarketing Experience The following adverse reactions have been identified during post approval use of tramadol. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Serotonin syndrome: Cases of serotonin syndrome, a potentially life-threatening condition, have been reported during concomitant use of opioids with serotonergic drugs. Adrenal insufficiency: Cases of adrenal insufficiency have been reported with opioid use, more often following greater than one month of use. Anaphylaxis: Anaphylaxis has been reported with ingredients contained in tramadol hydrochloride extended-release tablets. Androgen deficiency: Cases of androgen deficiency have occurred with use of opioids for an extended period of time . Hyperalgesia and Allodynia : Cases of hyperalgesia and allodynia have been reported with opioid therapy of any duration [see Warnings] Hyponatremia: Cases of severe hyponatremia and/or SIADH have been reported in patients taking tramadol, most often in females over the age of 65, and within the first week of therapy [see PRECAUTIONS ]. Hypoglycemia: Cases of hypoglycemia have been reported in patients taking tramadol. Most reports were in patients with predisposing risk factors, including diabetes or renal insufficiency, or in elderly patients [see PRECAUTIONS ]. Opioid-induced esophageal dysfunction (OIED): Cases of OIED have been reported in patients taking opioids, and may occur more frequently in patients taking higher doses of opioids, and/or in patients taking opioids longer term [see WARNINGS ].

Adverse

Reactions from Observational Studies A prospective, observational cohort study estimated the risks of addiction, abuse, and misuse in patients initiating long-term use of Schedule II opioid analgesics between 2017 and 2021. Study participants included in one or more analyses had been enrolled in selected insurance plans or health systems for at least one year, were free of at least one outcome at baseline, completed a minimum number of follow-up assessments, and either: 1) filled multiple extended-release/long-acting opioid analgesic prescriptions during a 90 day period (n=978); or 2) filled any Schedule II opioid analgesic prescriptions covering at least 70 of 90 days (n=1,244). Those included also had no dispensing of the qualifying opioids in the previous 6 months.

Over

12 months:

• approximately 1% to 6% of participants across the two cohorts newly met criteria for addiction, as assessed with two validated interview-based measures of moderate-to-severe opioid use disorder based on Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria, and
• approximately 9% and 22% of participants across the two cohorts newly met criteria for prescription opioid abuse and misuse [defined in DRUG ABUSE AND DEPENDENCE], respectively, as measured with a validated self-reported instrument. A retrospective, observational cohort study estimated the risk of opioid-involved overdose or opioid overdose-related death in patients with new long-term use of Schedule II opioid analgesics from 2006 through 2016 (n=220,249). Included patients had been enrolled in either one of two commercial insurance programs, one managed care program, or one Medicaid program for at least 9 months. New long-term use was defined as having Schedule II opioid analgesic prescriptions covering at least 70 days’ supply over the 3 months prior to study entry and none during the preceding 6 months. Patients were excluded if they had an opioid-involved overdose in the 9 months prior to study entry. Overdose was measured using a validated medical code-based algorithm with linkage to the National Death Index database.

The

5-year cumulative incidence estimates for opioid-involved overdose or opioid overdose-related death ranged from approximately 1.5% to 4% across study sites, counting only the first event during follow-up.

Approximately

17% of first opioid overdoses observed over the entire study period (5-11 years, depending on the study site) were fatal. Higher baseline opioid dose was the strongest and most consistent predictor of opioid-involved overdose or opioid overdose-related death. Study exclusion criteria may have selected patients at lower risk of overdose, and substantial loss to follow-up (approximately 80%) also may have biased estimates. The risk estimates from the studies described above may not be generalizable to all patients receiving opioid analgesics, such as those with exposures shorter or longer than the duration evaluated in the studies.

Drug Abuse And Dependence

Controlled Substance Tramadol hydrochloride extended-release tablets contain tramadol, a Schedule IV controlled substance.

Abuse

Tramadol hydrochloride extended-release tablets contain tramadol, a substance with high potential for misuse and abuse, which can lead to the development of substance use disorder, including addiction [see Warnings ] . Misuse is the intentional use, for therapeutic purposes, of a drug by an individual in a way other than prescribed by a healthcare provider or for whom it was not prescribed. Abuse is the intentional, non-therapeutic use of a drug, even once, for its desirable psychological or physiological effects. Drug addiction is a cluster of behavioral, cognitive, and physiological phenomena that may include a strong desire to take the drug, difficulties in controlling drug use (e.g., continuing drug use despite harmful consequences, giving a higher priority to drug use than other activities and obligations), and possible tolerance or physical dependence. Misuse and abuse of tramadol hydrochloride extended-release tablets increases risk of overdose, which may lead to central nervous system and respiratory depression, hypotension, seizures, and death. The risk is increased with concurrent use of tramadol hydrochloride extended-release tablets with alcohol and/or other CNS depressants. Abuse of and addiction to opioids in some individuals may not be accompanied by concurrent tolerance and symptoms of physical dependence. In addition, abuse of opioids can occur in the absence of addiction. All patients treated with opioids require careful and frequent re-evaluation for signs of misuse, abuse, and addiction, because use of opioid analgesic products carries the risk of addiction even under appropriate medical use. Patients at high risk of tramadol hydrochloride extended-release tablets abuse include those with a history of prolonged use of any opioids, including products containing tramadol, those with a history of drug or alcohol abuse, or those who use tramadol hydrochloride extended-release tablets in combination with other abused drugs. “Drug-seeking” behavior is very common in persons with substance use disorders. Drug-seeking tactics include emergency calls or visits near the end of office hours, refusal to undergo appropriate examination, testing, or referral, repeated “loss” of prescriptions, tampering with prescriptions, and reluctance to provide prior medical records or contact information for other treating healthcare provider(s). “Doctor shopping” (visiting multiple prescribers to obtain additional prescriptions) is common among people who abuse drugs and people with substance use disorder. Preoccupation with achieving adequate pain relief can be appropriate behavior in a patient with inadequate pain control. Tramadol hydrochloride extended-release tablets, like other opioids, can be diverted for nonmedical use into illicit channels of distribution. Careful record-keeping of prescribing information, including quantity, frequency, and renewal requests, as required by state and federal law, is strongly advised. Proper assessment of the patient, proper prescribing practices, periodic reevaluation of therapy, and proper dispensing and storage are appropriate measures that help to limit abuse of opioid drugs.

Risks

Specific to Abuse of Tramadol Hydrochloride Extended-Release Tablets Abuse of tramadol hydrochloride extended-release tablets poses a risk of overdose and death. Tramadol hydrochloride extended-release tablets are approved for oral use only. Inappropriate intravenous, intramuscular, or subcutaneous use of tramadol hydrochloride extended-release tablets can result in local tissue necrosis, infection, pulmonary granulomas, increased risk of endocarditis and valvular heart injury, embolism, and death. Parenteral drug abuse is commonly associated with transmission of infectious diseases such as hepatitis and HIV.

Dependence

Both tolerance and physical dependence can develop during use of opioid therapy. Tolerance is a physiological state characterized by a reduced response to a drug after repeated administration (i.e., a higher dose of a drug is required to produce the same effect that was once obtained at a lower dose). Physical dependence is a state that develops as a result of a physiological adaptation in response to repeated drug use, manifested by withdrawal signs and symptoms after abrupt discontinuation or a significant dose reduction of a drug. Withdrawal may be precipitated through the administration of drugs with opioid antagonist activity (e.g., naloxone, nalmefene), mixed agonist/antagonist analgesics (e.g., pentazocine, butorphanol, nalbuphine), or partial agonists (e.g., buprenorphine). Physical dependence may not occur to a clinically significant degree until after several days to weeks of continued use. Do not rapidly reduce or abruptly discontinue tramadol hydrochloride extended-release tablets in a patient physically dependent on opioids. Rapid reduction or abrupt discontinuation of tramadol hydrochloride extended-release tablets in a patient physically dependent on opioids may lead to serious withdrawal symptoms, uncontrolled pain, and suicide. Rapid reduction or abrupt discontinuation has also been associated with attempts to find other sources of opioid analgesics, which may be confused with drug-seeking for abuse. When discontinuing tramadol hydrochloride extended-release tablets, gradually taper the dosage using a patient-specific plan that considers the following: the dose of tramadol hydrochloride extended-release tablets the patient has been taking, the duration of treatment, and the physical and psychological attributes of the patient. To improve the likelihood of a successful taper and minimize withdrawal symptoms, it is important that the opioid tapering schedule is agreed upon by the patient. In patients taking opioids for an extended period of time at high doses, ensure that a multimodal approach to pain management, including mental health support (if needed), is in place prior to initiating an opioid analgesic taper [see Dosage and Administration , and Warnings ] . Infants born to mothers physically dependent on opioids will also be physically dependent and may exhibit respiratory difficulties and withdrawal signs [see Precautions; Pregnancy ] .

AND PRECAUTIONS Opioid Induced Hyperalgesia (OIH) and Allodynia : Opioid-Induced Hyperalgesia (OIH) occurs when an opioid analgesic paradoxically causes an increase in pain, or an increase in sensitivity to pain. If OIH is suspected, carefully consider appropriately decreasing the dose of the current opioid analgesic, or opioid rotation. ( 5.8 )

Serotonin

Syndrome with Concomitant Use of Serotonergic Drugs : Potentially life-threatening condition could result from concomitant serotonergic drug administration. Discontinue tramadol hydrochloride extended-release tablets if serotonin syndrome is suspected. ( 5.9 )

Increased

Risk of Seizures : Present within recommended dosage range. Risk is increased with higher than recommended doses and concomitant use of SSRIs, SNRIs, anorectics, tricyclic antidepressants and other tricyclic compounds, other opioids, MAOIs, neuroleptics, other drugs that reduce seizure threshold, in patients with epilepsy or at risk for seizures. ( 5.10 , 7 ) Risk of Suicide : Do not use tramadol hydrochloride extended-release tablets in suicidal or addiction-prone patients. Use with caution in those taking tranquilizers, antidepressants or abuse alcohol. ( 5.11 ) Life-Threatening Respiratory Depression in Patients with Chronic Pulmonary Disease or in Elderly, Cachectic, or Debilitated Patients : Regularly evaluate closely, particularly during initiation and titration. ( 5.12 )

Adrenal

Insufficiency : If diagnosed, treat with physiologic replacement of corticosteroids, and wean patient off of the opioid. ( 5.13 )

Severe

Hypotension : Regularly evaluate during dosage initiation and titration. Avoid use of tramadol hydrochloride extended-release tablets in patients with circulatory shock. ( 5.14 ) Risks of Use in Patients with Increased Intracranial Pressure, Brain Tumors, Head Injury, or Impaired Consciousness : Regularly evaluate for sedation and respiratory depression. Avoid use of tramadol hydrochloride extended-release tablets in patients with impaired consciousness or coma. ( 5.15 )

5.1 Addiction, Abuse, and Misuse Tramadol hydrochloride extended-release tablet contains tramadol, a Schedule IV controlled substance. As an opioid, tramadol hydrochloride extended-release tablet exposes users to the risks of addiction, abuse, and misuse. Although the risk of addiction in any individual is unknown, it can occur in patients appropriately prescribed tramadol hydrochloride extended-release tablets. Addiction can occur at recommended dosages and if the drug is misused or abused. The risk of opioid-related overdose or overdose related death is increased with higher opioid doses, and this risk persists over the course of therapy. In postmarketing studies, addiction, abuse, misuse, and fatal and non-fatal opioid overdose were observed in patients with long-term opioid use <span class="opacity-50 text-xs">[see Adverse Reactions ( 6.2 )]</span>. Assess each patient&apos;s risk for opioid addiction, abuse, or misuse prior to prescribing tramadol hydrochloride extended-release tablets, and reassess all patients receiving tramadol hydrochloride extended-release tablets for the development of these behaviors and conditions. Risks are increased in patients with a personal or family history of substance abuse (including drug or alcohol abuse or addiction) or mental illness (e.g., major depression). The potential for these risks should not, however, prevent the proper management of pain in any given patient. Patients at increased risk may be prescribed opioids such as tramadol hydrochloride extended-release tablets, but use in such patients necessitates intensive counseling about the risks and proper use of tramadol hydrochloride extended-release tablets along with frequent reevaluation for signs of addiction, abuse, and misuse. Consider recommending or prescribing an opioid overdose reversal agent <span class="opacity-50 text-xs">[see Dosage and Administration ( 2.2 ), Warnings and Precautions ( 5.2 ) . Abuse or misuse of tramadol hydrochloride extended-release tablets by cutting, breaking, chewing, crushing, snorting, or injecting the dissolved product will result in the uncontrolled delivery of tramadol and can result in overdose and death [see Overdosage ( 10 )]</span> . Opioids are sought for non-medical use and are subject to diversion from legitimate prescribed use. Consider these risks when prescribing or dispensing tramadol hydrochloride extended-release tablets. Strategies to reduce these risks include prescribing the drug in the smallest appropriate quantity and advising the patient on careful storage of the drug during the course of treatment and proper disposal of unused drug. Contact local state professional licensing board or state-controlled substances authority for information on how to prevent and detect abuse or diversion of this product.

5.2 Life Threatening Respiratory Depression Serious, life-threatening, or fatal respiratory depression has been reported with the use of opioids, even when used as recommended. Respiratory depression, if not immediately recognized and treated, may lead to respiratory arrest and death. Management of respiratory depression may include close observation, supportive measures, and use of opioid overdose reversal agents, depending on the patient&apos;s clinical status <span class="opacity-50 text-xs">[see Overdosage ( 10 )]</span> . Carbon dioxide (CO 2 ) retention from opioid-induced respiratory depression can exacerbate the sedating effects of opioids. While serious, life-threatening, or fatal respiratory depression can occur at any time during the use of tramadol hydrochloride extended-release tablets, the risk is greatest during the initiation of therapy or following a dosage increase of tramadol hydrochloride extended-release tablets. To reduce the risk of respiratory depression, proper dosing and titration of tramadol hydrochloride extended-release tablets are essential <span class="opacity-50 text-xs">[see Dosage and Administration ( 2 )]</span> . Overestimating the tramadol hydrochloride extended-release tablets dosage when converting patients from another opioid product can result in a fatal overdose with the first dose. Accidental ingestion of even one dose of tramadol hydrochloride extended-release tablets, especially by children, can result in respiratory depression and death due to an overdose of tramadol. Educate patients and caregivers on how to recognize respiratory depression and emphasize the importance of calling 911 or getting emergency medical help right away in the event of a known or suspected overdose . Opioids can cause sleep-related breathing disorders including central sleep apnea (CSA) and sleep-related hypoxemia. Opioid use increases the risk of CSA in a dose-dependent fashion. In patients who present with CSA, consider decreasing the opioid dosage using best practices for opioid taper <span class="opacity-50 text-xs">[see Dosage and Administration ( 2.5 )]</span>.

Patient

Access to an Opioid Overdose Reversal Agent for the Emergency Treatment of Opioid Overdose Inform patients and caregivers about opioid overdose reversal agents (e.g., naloxone, nalmefene). Discuss the importance of having access to an opioid overdose reversal agent, especially if the patient has risk factors for overdose (e.g., concomitant use of CNS depressants, a history of opioid use disorder, or prior opioid overdose) or if there are household members (including children) or other close contacts at risk for accidental ingestion or opioid overdose. The presence of risk factors for overdose should not prevent the management of pain in any patient. [See Warnings and Precautions ( 5.1 , 5.3 ]. Discuss the options for obtaining an opioid overdose reversal agent (e.g., prescription, over-the-counter, or as part of a community-based program). There are important differences among the opioid overdose reversal agents, such as route of administration, product strength, approved patient age range, and pharmacokinetics. Be familiar with these differences, as outlined in the approved labeling for those products, prior to recommending or prescribing such an agent. Educate patients and caregivers on how to recognize respiratory depression, and how to use an opioid overdose reversal agent for the emergency treatment of opioid overdose. Emphasize the importance of calling 911 or getting emergency medical help, even if an opioid overdose reversal agent is administered [see Dosage and Administration ( 2.2 ), Warnings and Precautions ( 5.1 , 5.3 ), Overdosage ( 10 )].

5.3 Risks from Concomitant Use with Benzodiazepines or Other CNS Depressants Profound sedation, respiratory depression, coma, and death may result from the concomitant use of tramadol hydrochloride extended-release tablets with benzodiazepines and/or other CNS depressants, including alcohol (e.g., non-benzodiazepine sedatives/hypnotics, anxiolytics, tranquilizers, muscle relaxants, general anesthetics, antipsychotics, gabapentinoids [gabapentin or pregabalin], and other opioids). Because of these risks, reserve concomitant prescribing of these drugs for use in patients for whom alternative treatment options are inadequate. Observational studies have demonstrated that concomitant use of opioid analgesics and benzodiazepines increases the risk of drug-related mortality compared to use of opioid analgesics alone. Because of similar pharmacological properties, it is reasonable to expect similar risk with the concomitant use of other CNS depressant drugs with opioid analgesics <span class="opacity-50 text-xs">[see Drug Interactions ( 7 )]</span> . If the decision is made to prescribe a benzodiazepine or other CNS depressant concomitantly with an opioid analgesic, prescribe the lowest effective dosages and minimum durations of concomitant use. In patients already receiving an opioid analgesic, prescribe a lower initial dose of the benzodiazepine or other CNS depressant than indicated in the absence of an opioid, and titrate based on clinical response. If an opioid analgesic is initiated in a patient already taking a benzodiazepine or other CNS depressant, prescribe a lower initial dose of the opioid analgesic, and titrate based on clinical response. Inform patients and caregivers of this potential interaction and educate them on the signs and symptoms of respiratory depression (including sedation). If concomitant use is warranted, consider recommending or prescribing an opioid overdose reversal agent <span class="opacity-50 text-xs">[see Dosage and Administration ( 2.2 ), Warnings and Precautions ( 5.2 ), Overdosage ( 10 )]</span> . Advise both patients and caregivers about the risks of respiratory depression and sedation when tramadol hydrochloride extended-release tablets are used with benzodiazepines or other CNS depressants (including alcohol and illicit drugs). Advise patients not to drive or operate heavy machinery until the effects of concomitant use of the benzodiazepine or other CNS depressants have been determined. Screen patients for risk of substance use disorders, including opioid abuse and misuse, and warn them of the risk for overdose and death associated with the use of additional CNS depressants including alcohol and illicit drugs <span class="opacity-50 text-xs">[see Drug Interactions ( 7 )]</span> .

5.4 Neonatal Opioid Withdrawal Syndrome (NOWS) Use of tramadol hydrochloride extended-release tablets for an extended period of time during pregnancy can result in withdrawal in the neonate. Neonatal opioid withdrawal syndrome, unlike opioid withdrawal syndrome in adults, may be life-threatening if not recognized and treated, and requires management according to protocols developed by neonatology experts. Observe newborns for signs of neonatal opioid withdrawal syndrome and manage accordingly. Advise pregnant women using opioids for an extended period of time of the risk of neonatal opioid withdrawal syndrome and ensure that appropriate treatment will be available <span class="opacity-50 text-xs">[see Use in Specific Populations ( 8.1 ), Patient Counseling Information ( 17 )]</span> .

5.5 Opioid Analgesic Risk Evaluation and Mitigation Strategy (REMS) To ensure that the benefits of opioid analgesics outweigh the risks of addiction, abuse, and misuse, the Food and Drug Administration (FDA) has required a Risk Evaluation and Mitigation Strategy (REMS) for these products. Under the requirements of the REMS, drug companies with approved opioid analgesic products must make REMS compliant education programs available to healthcare providers. Healthcare providers are strongly encouraged to do all of the following: Complete a REMS-compliant education program offered by an accredited provider of continuing education (CE) or another education program that includes all the elements of the FDA Education Blueprint for Health Care Providers Involved in the Management or Support of Patients with Pain. Discuss the safe use, serious risks, and proper storage and disposal of opioid analgesics with patients and/or their caregivers every time these medicines are prescribed.

The Patient Counseling

Guide (PCG) can be obtained at this link: www.fda.gov/OpioidAnalgesicREMSPCG . Emphasize to patients and their caregivers the importance of reading the Medication Guide that they will receive from their pharmacist every time an opioid analgesic is dispensed to them. Consider using other tools to improve patient, household, and community safety, such as patient-prescriber agreements that reinforce patient-prescriber responsibilities. To obtain further information on the opioid analgesic REMS and for a list of accredited REMS CME/CE, call 800-503-0784, or log on to www.opioidanalgesicrems.com . The FDA Blueprint can be found at www.fda.gov/OpioidAnalgesicREMSBlueprint .

5.6 Ultra-Rapid Metabolism of Tramadol and Other Risk Factors for Life-threatening Respiratory Depression in Children Life-threatening respiratory depression and death have occurred in children who received tramadol. Tramadol and codeine are subject to variability in metabolism based upon CYP2D6 genotype (described below), which can lead to increased exposure to an active metabolite. Based upon postmarketing reports with tramadol or with codeine, children younger than 12 years of age may be more susceptible to the respiratory depressant effects of tramadol. Furthermore, children with obstructive sleep apnea who are treated with opioids for post-tonsillectomy and/or adenoidectomy pain may be particularly sensitive to their respiratory depressant effect. Because of the risk of life-threatening respiratory depression and death: Tramadol hydrochloride extended-release tablets are contraindicated for all children younger than 12 years of age <span class="opacity-50 text-xs">[see Contraindications ( 4 )]</span>. Tramadol hydrochloride extended-release tablets are contraindicated for post-operative management in pediatric patients younger than 18 years of age following tonsillectomy and/or adenoidectomy <span class="opacity-50 text-xs">[see Contraindications ( 4 )]</span> . Avoid the use of tramadol hydrochloride extended-release tablets in adolescents 12 to 18 years of age who have other risk factors that may increase their sensitivity to the respiratory depressant effects of tramadol unless the benefits outweigh the risks. Risk factors include conditions associated with hypoventilation, such as postoperative status, obstructive sleep apnea, obesity, severe pulmonary disease, neuromuscular disease, and concomitant use of other medications that cause respiratory depression. As with adults, when prescribing opioids for adolescents, healthcare providers should choose the lowest effective dose for the shortest period of time and inform patients and caregivers about these risks and the signs of opioid overdose <span class="opacity-50 text-xs">[see Use in Specific Populations ( 8.4 ), Overdosage ( 10 )]</span>.

Nursing Mothers

Tramadol is subject to the same polymorphic metabolism as codeine, with ultra-rapid metabolizers of CYP2D6 substrates being potentially exposed to life-threatening levels of O-desmethyltramadol (M1). At least one death was reported in a nursing infant who was exposed to high levels of morphine in breast milk because the mother was an ultra-rapid metabolizer of codeine. A baby nursing from an ultra-rapid metabolizer mother taking tramadol hydrochloride extended-release tablets could potentially be exposed to high levels of M1, and experience life-threatening respiratory depression. For this reason, breastfeeding is not recommended during treatment with tramadol hydrochloride extended-release tablets [see Use in Specific Populations ( 8.2 )] . CYP2D6 Genetic Variability: Ultra-rapid metabolizer Some individuals may be ultra-rapid metabolizers because of a specific CYP2D6 genotype (e.g., gene duplications denoted as *1/*1xN or *1/*2xN). The prevalence of this CYP2D6 phenotype varies widely and has been estimated at 1 to 10% for Whites (European, North American), 3 to 4% for Blacks (African Americans), 1 to 2% for East Asians (Chinese, Japanese, Korean), and may be greater than 10% in certain racial/ethnic groups (i.e., Oceanian, Northern African, Middle Eastern, Ashkenazi Jews, Puerto Rican). These individuals convert tramadol into its active metabolite, O-desmethyltramadol (M1), more rapidly and completely than other people. This rapid conversion results in higher than expected serum M1 levels. Even at labeled dosage regimens, individuals who are ultra-rapid metabolizers may have life-threatening or fatal respiratory depression or experience signs of overdose (such as extreme sleepiness, confusion, or shallow breathing) [see Overdosage ( 10 )] . Therefore, individuals who are ultra-rapid metabolizers should not use tramadol hydrochloride extended-release tablets.

5.7 Risks of Interactions with Drugs Affecting Cytochrome P450 Isoenzymes The effects of concomitant use or discontinuation of cytochrome P450 3A4 inducers, 3A4 inhibitors, or 2D6 inhibitors on levels of tramadol and M1 from tramadol hydrochloride extended-release tablets are complex. Use of cytochrome P450 3A4 inducers, 3A4 inhibitors, or 2D6 inhibitors with tramadol hydrochloride extended-release tablet requires careful consideration of the effects on the parent drug, tramadol which is a weak serotonin and norepinephrine reuptake inhibitor and µ-opioid agonist, and the active metabolite, M1, which is more potent than tramadol in µ-opioid receptor binding <span class="opacity-50 text-xs">[see Drug Interactions ( 7 )]</span> . Risks of Concomitant Use or Discontinuation of Cytochrome P450 2D6 Inhibitors The concomitant use of tramadol hydrochloride extended-release tablets with all cytochrome P450 2D6 inhibitors (e.g., amiodarone, quinidine) may result in an increase in tramadol plasma levels and a decrease in the levels of the active metabolite, M1. A decrease in M1 exposure in patients who have developed physical dependence to tramadol, may result in signs and symptoms of opioid withdrawal and reduced efficacy. The effect of increased tramadol levels may be an increased risk for serious adverse events including seizures and serotonin syndrome. Discontinuation of a concomitantly used cytochrome P450 2D6 inhibitor may result in a decrease in tramadol plasma levels and an increase in active metabolite M1 levels, which could increase or prolong adverse reactions related to opioid toxicity and may cause potentially fatal respiratory depression. Evaluate patients receiving tramadol hydrochloride extended-release tablets and any CYP2D6 inhibitor at frequent intervals for the risk of serious adverse events including seizures and serotonin syndrome, signs and symptoms that may reflect opioid toxicity, and opioid withdrawal when tramadol hydrochloride extended-release tablets are used in conjunction with inhibitors of CYP2D6 <span class="opacity-50 text-xs">[see Drug Interactions ( 7 )]</span> . Cytochrome P450 3A4 Interaction The concomitant use of tramadol hydrochloride extended-release tablets with cytochrome P450 3A4 inhibitors, such as macrolide antibiotics (e.g., erythromycin), azole-antifungal agents (e.g., ketoconazole), and protease inhibitors (e.g., ritonavir) or discontinuation of a cytochrome P450 3A4 inducer such as rifampin, carbamazepine, and phenytoin, may result in an increase in tramadol plasma concentrations, which could increase or prolong adverse reactions, increase the risk for serious adverse events including seizures and serotonin syndrome, and may cause potentially fatal respiratory depression. The concomitant use of tramadol hydrochloride extended-release tablets with all cytochrome P450 3A4 inducers or discontinuation of a cytochrome P450 3A4 inhibitor may result in lower tramadol levels. This may be associated with a decrease in efficacy, and in some patients, may result in signs and symptoms of opioid withdrawal. Evaluate patients receiving tramadol hydrochloride extended-release tablets and any CYP3A4 inhibitor at frequent intervals for the risk for serious adverse events including seizures and serotonin syndrome, signs and symptoms that may reflect opioid toxicity and opioid withdrawal when tramadol hydrochloride extended-release tablets are used in conjunction with inhibitors and inducers of CYP3A4 <span class="opacity-50 text-xs">[see Drug Interactions ( 7 )]</span> .

5.8 Opioid-Induced Hyperalgesia and Allodynia Opioid-Induced Hyperalgesia (OIH) occurs when an opioid analgesic paradoxically causes an increase in pain, or an increase in sensitivity to pain. This condition differs from tolerance, which is the need for increasing doses of opioids to maintain a defined effect [ see Dependence ( 9.3 ) ]. Symptoms of OIH include (but may not be limited to) increased levels of pain upon opioid dosage increase, decreased levels of pain upon opioid dosage decrease, or pain from ordinarily non-painful stimuli (allodynia). These symptoms may suggest OIH only if there is no evidence of underlying disease progression, opioid tolerance, opioid withdrawal, or addictive behavior. Cases of OIH have been reported, both with short-term and longer-term use of opioid analgesics. Though the mechanism of OIH is not fully understood, multiple biochemical pathways have been implicated. Medical literature suggests a strong biologic plausibility between opioid analgesics and OIH and allodynia. If a patient is suspected to be experiencing OIH, carefully consider appropriately decreasing the dose of the current opioid analgesic, or opioid rotation (safely switching the patient to a different opioid moiety) [ see Dosage and Administration ( 2.2 ); Warnings and Precautions ( 5.7 ) ].

5.9 Serotonin Syndrome with Concomitant Use of Serotonergic Drugs Cases of serotonin syndrome, a potentially life-threatening condition, have been reported with the use of tramadol products, including tramadol hydrochloride extended-release tablets, particularly during concomitant use with serotonergic drugs. Serotonergic drugs include selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), triptans, 5-HT3 receptor antagonists, drugs that affect the serotonergic neurotransmitter system (e.g., mirtazapine, trazodone, tramadol), certain muscle relaxants (i.e., cyclobenzaprine, metaxalone), and drugs that impair metabolism of serotonin (including monoamine oxidase inhibitors, both those intended to treat psychiatric disorders and also others, such as linezolid and intravenous methylene blue) <span class="opacity-50 text-xs">[see Drug Interactions ( 7 )]</span> . This may occur within the recommended dosage range. Serotonin syndrome symptoms may include mental status changes (e.g., agitation, hallucinations, coma), autonomic instability (e.g., tachycardia, labile blood pressure, hyperthermia), neuromuscular aberrations (e.g., hyperreflexia, incoordination, rigidity), and/or gastrointestinal symptoms (e.g., nausea, vomiting, diarrhea). The onset of symptoms generally occurs within several hours to a few days of concomitant use, but may occur later than that. Discontinue tramadol hydrochloride extended-release tablets if serotonin syndrome is suspected.

5.10 Increased Risk of Seizures Seizures have been reported in patients receiving tramadol within the recommended dosage range. Spontaneous post-marketing reports indicate that seizure risk is increased with doses of tramadol above the recommended range. Concomitant use of tramadol increases the seizure risk in patients taking: <span class="opacity-50 text-xs">[see Drug Interactions ( 7 )]</span> . Selective serotonin re-uptake inhibitors (SSRIs) and Serotonin-norepinephrine re-uptake inhibitors (SNRIs) antidepressants or anorectics, Tricyclic antidepressants (TCAs), and other tricyclic compounds (e.g., cyclobenzaprine, promethazine, etc.), Other opioids, Monoamine oxidase inhibitors <span class="opacity-50 text-xs">[see Warnings and Precautions ( 5.8 ), Drug Interactions ( 7 )]</span> Neuroleptics, or Other drugs that reduce the seizure threshold. Risk of seizures may also increase in patients with epilepsy, those with a history of seizures, or in patients with a recognized risk for seizure (such as head trauma, metabolic disorders, alcohol and drug withdrawal, CNS infections). In tramadol overdose, administration of an opioid overdose reversal agent (e.g., naloxone or nalmefene) may increase the risk of seizure.

5.11 Suicide Risk Do not prescribe tramadol hydrochloride extended-release tablets for patients who are suicidal or addiction-prone. Consideration should be given to the use of non-narcotic analgesics in patients who are suicidal or depressed. <span class="opacity-50 text-xs">[see Drug Abuse and Dependence ( 9.2 )]</span> Prescribe tramadol hydrochloride extended-release tablets with caution for patients with a history of misuse and/or who are currently taking CNS-active drugs including tranquilizers, or antidepressant drugs, or alcohol in excess, and patients who suffer from emotional disturbance or depression <span class="opacity-50 text-xs">[see Drug Interactions ( 7 )]</span> . Inform patients not to exceed the recommended dose and to limit their intake of alcohol <span class="opacity-50 text-xs">[see Dosage and Administration ( 2.1 ), Warnings and Precautions ( 5.7 , 5.8 , 5.14 )]</span> .

5.12 Life-Threatening Respiratory Depression in Patients with Chronic Pulmonary Disease or in Elderly, Cachectic, or Debilitated Patients The use of tramadol hydrochloride extended-release tablets in patients with acute or severe bronchial asthma in an unmonitored setting or in the absence of resuscitative equipment is contraindicated. Patients with Chronic Pulmonary Disease: Tramadol hydrochloride extended-release tablets-treated patients with significant chronic obstructive pulmonary disease or cor pulmonale, and those with a substantially decreased respiratory reserve, hypoxia, hypercapnia, or pre-existing respiratory depression are at increased risk of decreased respiratory drive including apnea, even at recommended dosages of tramadol hydrochloride extended-release tablets <span class="opacity-50 text-xs">[see Warnings and Precautions ( 5.3 )]</span> . Elderly, Cachectic, or Debilitated Patients: Life-threatening respiratory depression is more likely to occur in elderly, cachectic, or debilitated patients because they may have altered pharmacokinetics or altered clearance compared to younger, healthier patients <span class="opacity-50 text-xs">[see Warnings and Precautions ( 5.3 )]</span>. Regularly evaluate patients, particularly when initiating and titrating tramadol hydrochloride extended-release tablets and when tramadol hydrochloride extended-release tablets are given concomitantly with other drugs that depress respiration <span class="opacity-50 text-xs">[see Warnings and Precautions ( 5.3 , 5.6 )]</span> . Alternatively, consider the use of non-opioid analgesics in these patients.

5.13 Adrenal Insufficiency Cases of adrenal insufficiency have been reported with opioid use, more often following greater than one month of use. Presentation of adrenal insufficiency may include non-specific symptoms and signs including nausea, vomiting, anorexia, fatigue, weakness, dizziness, and low blood pressure. If adrenal insufficiency is suspected, confirm the diagnosis with diagnostic testing as soon as possible. If adrenal insufficiency is diagnosed, treat with physiologic replacement doses of corticosteroids. Wean the patient off of the opioid to allow adrenal function to recover and continue corticosteroid treatment until adrenal function recovers. Other opioids may be tried as some cases reported use of a different opioid without recurrence of adrenal insufficiency. The information available does not identify any particular opioids as being more likely to be associated with adrenal insufficiency.

5.14 Severe Hypotension Tramadol hydrochloride extended-release tablets may cause severe hypotension including orthostatic hypotension and syncope in ambulatory patients. There is increased risk in patients whose ability to maintain blood pressure has already been compromised by a reduced blood volume or concurrent administration of certain CNS depressant drugs (e.g., phenothiazines or general anesthetics) <span class="opacity-50 text-xs">[see Drug Interactions ( 7 )]</span> . Regularly evaluate these patients for signs of hypotension after initiating or titrating the dosage of tramadol hydrochloride extended-release tablets. In patients with circulatory shock, tramadol hydrochloride extended-release tablets may cause vasodilation that can further reduce cardiac output and blood pressure. Avoid the use of tramadol hydrochloride extended-release tablets in patients with circulatory shock.

5.15 Risks of Use in Patients with Increased Intracranial Pressure, Brain Tumors, Head Injury, or Impaired Consciousness In patients who may be susceptible to the intracranial effects of CO 2 retention (e.g., those with evidence of increased intracranial pressure or brain tumors), tramadol hydrochloride extended-release tablets may reduce respiratory drive, and the resultant CO 2 retention can further increase intracranial pressure. Monitor such patients for signs of sedation and respiratory depression, particularly when initiating therapy with tramadol hydrochloride extended-release tablets. Opioids may also obscure the clinical course in a patient with a head injury. Avoid the use of tramadol hydrochloride extended-release tablets in patients with impaired consciousness or coma.

5.16 Risks of Gastrointestinal Complication Tramadol hydrochloride extended-release tablets are contraindicated in patients with known or suspected gastrointestinal obstruction, including paralytic ileus. The tramadol in tramadol hydrochloride extended-release tablets may cause spasm of the sphincter of Oddi. Opioids may cause increases in serum amylase. Regularly evaluate patients with biliary tract disease, including acute pancreatitis, for worsening symptoms. Cases of opioid-induced esophageal dysfunction (OIED) have been reported in patients taking opioids. The risk of OIED may increase as the dose and/or duration of opioids increases. Regularly evaluate patients for signs and symptoms of OIED (e.g., dysphagia, regurgitation, non-cardiac chest pain) and, if necessary, adjust opioid therapy as clinically appropriate <span class="opacity-50 text-xs">[see Clinical Pharmacology ( 12.2 ) ]</span>.

5.17 Anaphylaxis and Other Hypersensitivity Reactions Serious and rarely fatal hypersensitive reactions have been reported in patients receiving therapy with tramadol. When these events do occur it is often following the first dose. Other reported hypersensitivity reactions include pruritus, hives, bronchospasm, angioedema, toxic epidermal necrolysis and Stevens-Johnson syndrome. Patients with a history of hypersensitivity reactions to tramadol and other opioids may be at increased risk and therefore should not receive tramadol hydrochloride extended-release tablets. If anaphylaxis or other hypersensitivity occurs, stop administration of tramadol hydrochloride extended-release tablets immediately, discontinue tramadol hydrochloride extended-release tablets permanently, and do not rechallenge with any formulation of tramadol. Advise patients to seek immediate medical attention if they experience any symptoms of a hypersensitivity reaction <span class="opacity-50 text-xs">[see Patient Counseling Information ( 17 )]</span> .

5.18 Withdrawal Do not rapidly reduce or abruptly discontinue tramadol hydrochloride extended-release tablets in a patient physically dependent on opioids. When discontinuing tramadol hydrochloride extended-release tablets in a physically dependent patient, gradually taper the dosage. Rapid tapering of tramadol hydrochloride extended-release tablets in a patient physically dependent on opioids may lead to a withdrawal syndrome and return of pain <span class="opacity-50 text-xs">[see Dosage and Administration ( 2.5 ), Drug Abuse and Dependence ( 9 )]</span> . Additionally, avoid the use of mixed agonist/antagonist (e.g., pentazocine, nalbuphine, and butorphanol) or partial agonist (e.g., buprenorphine) analgesics in patients who are receiving a full opioid agonist analgesic, including tramadol hydrochloride extended-release tablets. In these patients, mixed agonist/antagonist and partial agonist analgesics may reduce the analgesic effect and/or precipitate withdrawal symptoms <span class="opacity-50 text-xs">[see Drug Interactions ( 7 )]</span> . When discontinuing tramadol hydrochloride extended-release tablets, gradually taper the dosage <span class="opacity-50 text-xs">[see Dosage and Administration ( 2.5 )]</span> . Do not abruptly discontinue tramadol hydrochloride extended-release tablets <span class="opacity-50 text-xs">[see Drug Abuse and Dependence ( 9.3 )]</span> .

5.19 Risks of Driving and Operating Machinery Tramadol hydrochloride extended-release tablets may impair the mental or physical abilities needed to perform potentially hazardous activities such as driving a car or operating machinery. Warn patients not to drive or operate dangerous machinery unless they are tolerant to the effects of tramadol hydrochloride extended-release tablets and know how they will react to the medication <span class="opacity-50 text-xs">[see Patient Counseling Information ( 17 )]</span> .

5.20 Hyponatremia Hyponatremia (serum sodium &lt; 135 mmol/L) has been reported with the use of tramadol, and many cases are severe (sodium level &lt; 120 mmol/L). Most cases of hyponatremia occurred in females over the age of 65 and within the first week of therapy. In some reports, hyponatremia resulted from the syndrome of inappropriate antidiuretic hormone secretion (SIADH). Assess patients for signs and symptoms of hyponatremia (e.g., confusion, disorientation), during treatment with tramadol hydrochloride extended-release tablets, especially during initiation of therapy. If signs and symptoms of hyponatremia are present, initiate appropriate treatment (e.g., fluid restriction) and discontinue tramadol hydrochloride extended-release tablets <span class="opacity-50 text-xs">[see Dosage and Administration: Safe Reduction or Discontinuation of tramadol hydrochloride extended-release tablets ( 2.5 )]</span> .

5.21 Hypoglycemia Cases of tramadol- associated hypoglycemia have been reported, some resulting in hospitalization. In most cases, patients had predisposing risk factors (e.g. diabetes). If hypoglycemia is suspected, monitor blood glucose levels and consider drug discontinuation as appropriate <span class="opacity-50 text-xs">[see Dosage and Administration: Safe Reduction or Discontinuation of tramadol hydrochloride extended-release tablets ( 2.5 )]</span> .

PRECAUTIONS Use in Renal and Hepatic Disease Impaired renal function results in a decreased rate and extent of excretion of tramadol and its active metabolite, M1 in patients taking an immediate-release formulation of tramadol. Tramadol hydrochloride extended-release tablets have not been studied in patients with renal impairment. The limited availability of dose strengths and once daily dosing of tramadol hydrochloride extended-release tablets do not permit the dosing flexibility required for safe use in patients with renal impairment. Therefore, tramadol hydrochloride extended-release tablets should not be used in patients with severe renal impairment [ s ee CLINICAL PHARMACOLOGY and DOSAGE and ADMINISTRATION ]. The metabolism of tramadol and M1 is reduced in patients with advanced cirrhosis of the liver. Tramadol hydrochloride extended-release tablets have not been studied in patients with hepatic impairment. The limited availability of dose strengths and once daily dosing of tramadol hydrochloride extended-release tablets do not permit the dosing flexibility required for safe use in patients with hepatic impairment. Therefore, tramadol hydrochloride extended-release tablets should not be used in patients with hepatic impairment [ s ee CLINICAL PHARMACOLOGY and DOSAGE and ADMINISTRATION ]. Information for Patients/Caregivers Advise the patient to read the FDA-approved patient labeling (Medication Guide). Storage and Disposal Because of the risks associated with accidental ingestion, misuse, and abuse, advise patients to store tramadol hydrochloride extended-release tablets securely, out of sight and reach of children, and in a location not accessible by others, including visitors to the home [see WARNINGS, DRUG ABUSE and DEPENDENCE ] . Inform patients that leaving tramadol hydrochloride extended-release tablets unsecured can pose a deadly risk to others in the home. Advise patients and caregivers that when medicines are no longer needed, they should be disposed of promptly. Inform patients that medicine take-back options are the preferred way to safely dispose of most types of unneeded medicines. If no take back programs or DEA-registered collectors are available, instruct patients to dispose of tramadol hydrochloride extended-release tablets by following these four steps: Mix tramadol hydrochloride extended-release tablets (do not crush) with an unpalatable substance such as dirt, cat litter, or used coffee grounds; Place the mixture in a container such as a sealed plastic bag; Throw the container in the household trash; Remove all personal information on the prescription label of the empty bottle Inform patients that they can visit www.fda.gov/drugdisposal for additional information on disposal of unused medicines. Addiction, Abuse, and Misuse Inform patients that the use of tramadol hydrochloride extended-release tablets, even when taken as recommended, can result in addiction, abuse, and misuse, which can lead to overdose and death [see WARNINGS] . Instruct patients not to share tramadol hydrochloride extended-release tablets with others and to take steps to protect tramadol hydrochloride extended-release tablets from theft or misuse. Life-Threatening Respiratory Depression Inform patients of the risk of life-threatening respiratory depression, including information that the risk is greatest when starting tramadol hydrochloride extended-release tablets or when the dosage is increased, and that it can occur even at recommended dosages. Educate patients and caregivers on how to recognize respiratory depression and emphasize the importance of calling 911 or getting emergency medical help right away in the event of a known or suspected overdose [see WARNINGS; Life Threatening Respiratory Depression].

Accidental Ingestion

Inform patients that accidental ingestion, especially by children, may result in respiratory depression or death [see WARNINGS] . Interactions with Benzodiazepines or Other CNS Depressants Inform patients and caregivers that potentially fatal additive effects may occur if tramadol hydrochloride extended-release tablets are used with benzodiazepines or other CNS depressants, including alcohol (e.g., non-benzodiazepine sedative/hypnotics, anxiolytics, tranquilizers, muscle relaxants, general anesthetics, antipsychotics, gabapentinoids [gabapentin or pregabalin], and other opioids), and not to use these concomitantly unless supervised by a healthcare provider [see WARNINGS and PRECAUTIONS; Drug Interactions ].

Patient

Access to an Opioid Overdose Reversal Agent for the Emergency Treatment of Opioid Overdose Inform patients and caregivers about opioid overdose reversal agents (e.g., naloxone, nalmefene). Discuss the importance of having access to an opioid overdose reversal agent, especially if the patient has risk factors for overdose (e.g., concomitant use of CNS depressants, a history of opioid use disorder, or prior opioid overdose) or if there are household members (including children) or other close contacts at risk for accidental ingestion or opioid overdose. Discuss with the patient the options for obtaining an opioid overdose reversal agent (e.g., prescription, over-the-counter, or as part of a community-based program) [see WARNINGS, DOSAGE AND ADMINISTRATION]. Educate patients and caregivers on how to recognize the signs and symptoms of an overdose. Explain to patients and caregivers that effects of opioid overdose reversal agents like naloxone and nalmefene are temporary, and that they must call 911 or get emergency medical help right away in all cases of known or suspected opioid overdose, even if an opioid overdose reversal agent is administered [see OVERDOSAGE ]. Advise patients and caregivers:

• how to treat with the overdose reversal agent in the event of an opioid overdose.
• to tell family and friends about their opioid overdose reversal agent, and to keep it in a place where family and friends can access it in an emergency.
• to read the Patient Information (or other educational material) that will come with their opioid overdose reversal agent. Emphasize the importance of doing this before an opioid emergency happens, so the patient and caregiver will know what to do. Ultra-Rapid Metabolism of Tramadol and Other Risk Factors for Life-threatening Respiratory Depression in Children Advise caregivers that tramadol hydrochloride extended-release tablets are contraindicated in all children younger than 12 years of age and in children younger than 18 years of age following tonsillectomy and/or adenoidectomy. Advise caregivers of children ages 12 to 18 years of age receiving tramadol hydrochloride extended-release tablets to monitor for signs of respiratory depression [see WARNINGS] . Hyperalgesia and Allodynia Inform patients and caregivers not to increase opioid dosage without first consulting a clinician. Advise patients to seek medical attention if they experience symptoms of hyperalgesia, including worsening pain, increased sensitivity to pain, or new pain [see Warnings ; Adverse Reactions ] .

Serotonin Syndrome

Inform patients that opioids could cause a rare but potentially life-threatening condition resulting from concomitant administration of serotonergic drugs. Warn patients of the symptoms of serotonin syndrome and to seek medical attention right away if symptoms develop. Instruct patients to inform their healthcare provider if they are taking, or plan to take serotonergic medications [see WARNINGS] .

Seizures

Inform patients that tramadol hydrochloride extended-release tablets may cause seizures with concomitant use of serotonergic agents (including SSRIs, SNRIs, and triptans) or drugs that significantly reduce the metabolic clearance of tramadol [see WARNINGS ] .

Maoi

Interaction Inform patients not to take tramadol hydrochloride extended-release tablets while using any drugs that inhibit monoamine oxidase. Patients should not start MAOIs while taking tramadol hydrochloride extended-release tablets [see PRECAUTIONS; Drug Interactions ].

Important Administration Instructions

Instruct patients how to properly take tramadol hydrochloride extended-release tablets, including the following: Tramadol hydrochloride extended-release tablets are designed to work properly only if swallowed intact. Taking cut, broken, chewed, crushed, or dissolved tramadol hydrochloride extended-release tablets can result in a fatal overdose [see DOSAGE and ADMINISTRATION ]. Advise patients not to exceed the single-dose and 24-hour dose limit and the time interval between doses, since exceeding these recommendations can result in respiratory depression, seizures, hepatic toxicity, and death. [see DOSAGE and ADMINISTRATION ]. Do not discontinue tramadol hydrochloride extended-release tablets without first discussing the need for a tapering regimen with the prescriber [see DOSAGE and ADMINISTRATION ] .

Important Discontinuation

Instructions In order to avoid developing withdrawal symptoms, instruct patients not to discontinue tramadol hydrochloride extended-release tablets without first discussing a tapering plan with the prescriber [see DOSAGE and ADMINISTRATION ]. Driving or Operating Heavy Machinery Inform patients that tramadol hydrochloride extended-release tablets may impair the ability to perform potentially hazardous activities such as driving a car or operating heavy machinery. Advise patients not to perform such tasks until they know how they will react to the medication [see WARNINGS ] .

Constipation

Advise patients of the potential for severe constipation, including management instructions and when to seek medical attention [see ADVERSE REACTIONS , CLINICAL PHARMACOLOGY ].

Adrenal Insufficiency

Inform patients that opioids could cause adrenal insufficiency, a potentially life-threatening condition. Adrenal insufficiency may present with non-specific symptoms and signs such as nausea, vomiting, anorexia, fatigue, weakness, dizziness, and low blood pressure. Advise patients to seek medical attention if they experience a constellation of these symptoms [see WARNINGS] .

Hypotension

Inform patients that tramadol hydrochloride extended-release tablets may cause orthostatic hypotension and syncope. Instruct patients how to recognize symptoms of low blood pressure and how to reduce the risk of serious consequences should hypotension occur (e.g., sit or lie down, carefully rise from a sitting or lying position) [see WARNINGS ] .

Anaphylaxis

Inform patients that anaphylaxis has been reported with ingredients contained in tramadol hydrochloride extended-release tablets. Advise patients how to recognize such a reaction and when to seek medical attention [see CONTRAINDICATIONS, ADVERSE REACTIONS ].

Pregnancy Neonatal Opioid Withdrawal Syndrome

Inform female patients of reproductive potential that use of tramadol hydrochloride extended-release tablets for an extended period of time during pregnancy can result in neonatal opioid withdrawal syndrome, which may be life-threatening if not recognized and treated [see WARNINGS, PRECAUTIONS; Pregnancy ]. Embryo-Fetal Toxicity Inform female patients of reproductive potential that tramadol hydrochloride extended-release tablets can cause fetal harm and to inform their healthcare provider of a known or suspected pregnancy [see PRECAUTIONS; Pregnancy ].

Lactation

Advise women that breastfeeding is not recommended during treatment with tramadol hydrochloride extended-release tablets [see PRECAUTIONS; Nursing Mothers ].

Infertility

Inform patients that use of opioids for an extended period of time may cause reduced fertility. It is not known whether these effects on fertility are reversible [see ADVERSE REACTIONS ].

Drug Interactions

Inhibitors of CYP2D6 The concomitant use of tramadol hydrochloride extended-release tablets and CYP2D6 inhibitors such as quinidine, fluoxetine, paroxetine and bupropion may result in an increase in the plasma concentration of tramadol and a decrease in the plasma concentration of M1, particularly when an inhibitor is added after a stable dose of tramadol hydrochloride extended-release tablets is achieved. Since M1 is a more potent μ-opioid agonist, decreased M1 exposure could result in decreased therapeutic effects, and may result in signs and symptoms of opioid withdrawal in patients who had developed physical dependence to tramadol. Increased tramadol exposure can result in increased or prolonged therapeutic effects and increased risk for serious adverse events including seizures and serotonin syndrome. After stopping a CYP2D6 inhibitor, as the effects of the inhibitor decline, the tramadol plasma concentration will decrease and the M1 plasma concentration will increase which could increase or prolong therapeutic effects but also increase adverse reactions related to opioid toxicity, and may cause potentially fatal respiratory depression [see CLINICAL PHARMACOLOGY ] . If concomitant use of a CYP2D6 inhibitor is necessary, follow patients closely for adverse reactions including opioid withdrawal, seizures and serotonin syndrome. If a CYP2D6 inhibitor is discontinued, consider lowering tramadol hydrochloride extended-release tablets dosage until stable drug effects are achieved. Evaluate patients at frequent intervals for adverse events including respiratory depression and sedation. Inhibitors of CYP3A4 The concomitant use of tramadol hydrochloride extended-release tablets and CYP3A4 inhibitors such as macrolide antibiotics (e.g., erythromycin), azole-antifungal agents (e.g. ketoconazole), protease inhibitors (e.g., ritonavir) can increase the plasma concentration of tramadol and may result in a greater amount of metabolism via CYP2D6 and greater levels of M1. Follow patients closely for increased risk of serious adverse events including seizures and serotonin syndrome, and adverse reactions related to opioid toxicity including potentially fatal respiratory depression, particularly when an inhibitor is added after a stable dose of tramadol hydrochloride extended-release tablets is achieved. After stopping a CYP3A4 inhibitor, as the effects of the inhibitor decline, the tramadol plasma concentration will decrease [see CLINICAL PHARMACOLOGY ] , resulting in decreased opioid efficacy and possibly signs and symptoms of opioid withdrawal in patients who had developed physical dependence to tramadol. If concomitant use is necessary, consider dosage reduction of tramadol hydrochloride extended-release tablets until stable drug effects are achieved. Inform patients and caregivers of this potential interaction, educate them on the signs and symptoms of seizures, serotonin syndrome, and signs of respiratory depression and sedation. If a CYP3A4 inhibitor is discontinued, consider increasing the tramadol hydrochloride extended-release tablets dosage until stable drug effects are achieved and evaluate patients at frequent intervals for signs and symptoms of opioid withdrawal. CYP3A4 Inducers The concomitant use of tramadol hydrochloride extended-release tablets and CYP3A4 inducers such as rifampin, carbamazepine, phenytoin can decrease the plasma concentration of tramadol, [see CLINICAL PHARMACOLOGY ] , resulting in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence to tramadol [see WARNINGS ] . After stopping a CYP3A4 inducer, as the effects of the inducer decline, the tramadol plasma concentration will increase [see CLINICAL PHARMACOLOGY ] , which could increase or prolong both the therapeutic effects and adverse reactions, and may cause seizures and serotonin syndrome, and potentially fatal respiratory depression. If concomitant use is necessary, consider increasing the tramadol hydrochloride extended-release tablets dosage until stable drug effects are achieved. Evaluate patients for signs of opioid withdrawal. If a CYP3A4 inducer is discontinued, consider tramadol hydrochloride extended-release tablets dose reduction and evaluate patients at frequent intervals for signs of respiratory depression and sedation. Patients taking carbamazepine, a CYP3A4 inducer, may have a significantly reduced analgesic effect of tramadol. Because carbamazepine increases tramadol metabolism and because of the seizure risk associated with tramadol, concomitant administration of tramadol hydrochloride extended-release tablets and carbamazepine is not recommended. Benzodiazepines and Other Central Nervous System (CNS)

Depressants

Due to additive pharmacologic effect, the concomitant use of benzodiazepines or other CNS depressants such as alcohol, other sedatives/hypnotics, anxiolytics, tranquilizers, muscle relaxants, general anesthetics, antipsychotics, and other opioids, can increases the risk of respiratory depression, profound sedation, coma, and death. Reserve concomitant prescribing of these drugs for use in patients for whom alternative treatment options are inadequate. Limit dosages and durations to the minimum required. Inform patients and caregivers of this potential interaction, educate them on the signs and symptoms of respiratory depression (including sedation). If concomitant use is warranted, consider recommending or prescribing an opioid overdose reversal agent. [see WARNINGS, DOSAGE AND ADMINISTRATION].

Serotonergic Drugs

The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system such as selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), triptans, 5-HT3 receptor antagonists, drugs that affect the serotonin neurotransmitter system (e.g., mirtazapine, trazodone, tramadol), certain muscle relaxants (i.e., cyclobenzaprine, metaxalone), monoamine oxidase (MAO) inhibitors (those intended to treat psychiatric disorders and also others, such as linezolid and intravenous methylene blue) has resulted in serotonin syndrome. If concomitant use is warranted, carefully observe the patient, particularly during treatment initiation and dose adjustment. Discontinue tramadol hydrochloride extended-release tablets if serotonin syndrome is suspected.

Monoamine Oxidase

Inhibitors (MAOIs) MAOI interactions with opioids may manifest as serotonin syndrome [see WARNINGS ] or opioid toxicity (e.g., respiratory depression, coma) [see WARNINGS ]. Do not use tramadol hydrochloride extended-release tablets in patients taking MAOIs or within 14 days of stopping such treatment.

Mixed

Agonist/Antagonist and Partial Agonist Opioid Analgesics Mixed agonist/antagonist and partial agonist opioid analgesics such as butorphanol, nalbuphine, pentazocine, buprenorphine, may reduce the analgesic effect of tramadol hydrochloride extended-release tablets and/or precipitate withdrawal symptoms. Advise patient to avoid concomitant use of these drugs.

Muscle Relaxants

Tramadol hydrochloride extended-release tablets may enhance the neuromuscular blocking action of skeletal muscle relaxants and produce an increased degree of respiratory depression. Because respiratory depression may be greater than otherwise expected, decrease the dosage of tramadol hydrochloride extended-release tablets and/or the muscle relaxant as necessary. Due to the risk of respiratory depression with concomitant use of muscle relaxants and opioids, consider recommending or prescribing an opioid overdose reversal agent [see WARNINGS, DOSAGE AND ADMINISTRATION].

Diuretics

Opioids can reduce the efficacy of diuretics by inducing the release of antidiuretic hormone. Evaluate patients for signs of diminished diuresis and/or effects on blood pressure and increase the dosage of the diuretic as needed.

Anticholinergic Drugs

The concomitant use of anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Evaluate patients for signs of urinary retention or reduced gastric motility when tramadol hydrochloride extended-release tablets are used concomitantly with anticholinergic drugs.

Digoxin

Postmarketing surveillance has revealed rare reports of digoxin toxicity. Follow patients for signs of digoxin toxicity and adjust dosage of digoxin as needed.

Warfarin

Postmarketing surveillance of tramadol has revealed rare reports of alteration of warfarin effect, including elevation of prothrombin times. Monitor the prothrombin time of patients on warfarin for signs of an interaction and adjust the dosage of warfarin as needed. Carcinogenesis, Mutagenesis and Impairment of Fertility Carcinogenesis Carcinogenicity assessment has been conducted in mice, rats and p53(+/-) heterozygous mice. A slight but statistically significant increase in two common murine tumors, pulmonary and hepatic, was observed in an NMRI mouse carcinogenicity study, particularly in aged mice. Mice were dosed orally up to 30 mg/kg in the drinking water (0.5 times the maximum recommended daily human dosage or MRHD) for approximately two years, although the study was not done with the Maximum Tolerated Dose. This finding is not believed to suggest risk in humans.

Mutagenesis

Tramadol was mutagenic in the presence of metabolic activation in the mouse lymphoma assay. Tramadol was not mutagenic in the in vitro bacterial reverse mutation assay using Salmonella and E. coli (Ames), the mouse lymphoma assay in the absence of metabolic activation, the in vitro chromosomal aberration assay, or the in vivo micronucleus assay in bone marrow. Impairment of Fertility No effects on fertility were observed for tramadol at oral dose levels up to 50 mg/kg in male rats and 75 mg/kg in female rats. These dosages are 1.2 and 1.8 times the maximum recommended human daily dose based on body surface area, respectively.

Infertility

Use of opioids for an extended period of time may cause reduced fertility in females and males of reproductive potential. It is not known whether these effects on fertility are reversible [ see ADVERSE REACTIONS ].

Pregnancy Risk Summary

Use of opioid analgesics for an extended period of time during pregnancy may cause neonatal opioid withdrawal syndrome [see Warnings ] . Available data with tramadol hydrochloride extended-release tablets in pregnant women are insufficient to inform a drug-associated risk for major birth defects and miscarriage. In animal reproduction studies, tramadol administration during organogenesis decreased fetal weights and reduced ossification in mice, rats, and rabbits at 1.4, 0.6, and 3.6 times the maximum recommended human daily dosage (MRHD). Tramadol decreased pup body weight and increased pup mortality at 1.2 and 1.9 times the MRHD [see Data]. Based on animal data, advise pregnant women of the potential risk to a fetus. The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively.

Clinical Considerations Fetal/Neonatal

Adverse Reactions Use of opioid analgesics for an extended period of time during pregnancy for medical or nonmedical purposes can result in physical dependence in the neonate and neonatal opioid withdrawal syndrome shortly after birth. Neonatal opioid withdrawal syndrome presents as irritability, hyperactivity and abnormal sleep pattern, high pitched cry, tremor, vomiting, diarrhea, and failure to gain weight. The onset, duration, and severity of neonatal opioid withdrawal syndrome vary based on the specific opioid used, duration of use, timing and amount of last maternal use, and rate of elimination of the drug by the newborn. Observe newborns for symptoms and signs of neonatal opioid withdrawal syndrome and manage accordingly [see WARNINGS ] . Neonatal seizures, neonatal withdrawal syndrome, fetal death and stillbirth have been reported with tramadol hydrochloride during post-approval use of tramadol hydrochloride extended release tablets. Labor or Delivery Opioids cross the placenta and may produce respiratory depression and psycho-physiologic effects in neonates. An opioid overdose reversal agent, such as naloxone or nalmefene, must be available for reversal of opioid-induced respiratory depression in the neonate. Tramadol hydrochloride extended-release tablets are not recommended for use in pregnant women during or immediately prior to labor, when use of shorter-acting analgesics or other analgesic techniques are more appropriate. Opioid analgesics, including tramadol hydrochloride extended-release tablets, can prolong labor through actions which temporarily reduce the strength, duration, and frequency of uterine contractions. However, this effect is not consistent and may be offset by an increased rate of cervical dilation, which tends to shorten labor. Monitor neonates exposed to opioid analgesics during labor for signs of excess sedation and respiratory depression. Tramadol has been shown to cross the placenta. The mean ratio of serum tramadol in the umbilical veins compared to maternal veins was 0.83 for 40 women given tramadol during labor. The effect of tramadol hydrochloride extended-release tablets, if any, on the later growth, development, and functional maturation of the child is unknown.

Data Animal Data

Tramadol has been shown to be embryotoxic and fetotoxic in mice, (120 mg/kg), rats (25 mg/kg) and rabbits (75 mg/kg) at maternally toxic dosages, but was not teratogenic at these dose levels. These doses on a mg/m2 basis are 1.9, 0.8, and 4.9 times the maximum recommended human daily dosage (MRHD) for mouse, rat and rabbit, respectively. No drug-related teratogenic effects were observed in progeny of mice (up to 140 mg/kg), rats (up to 80 mg/kg) or rabbits (up to 300 mg/kg) treated with tramadol by various routes. Embryo and fetal toxicity consisted primarily of decreased fetal weights, decreased skeletal ossification, and increased supernumerary ribs at maternally toxic dose levels. Transient delays in developmental or behavioral parameters were also seen in pups from rat dams allowed to deliver. Embryo and fetal lethality were reported only in one rabbit study at 300 mg/kg, a dose that would cause extreme maternal toxicity in the rabbit. The dosages listed for mouse, rat, and rabbit are 2.3, 2.6, and 19 times the MRHD, respectively. Tramadol was evaluated in pre- and post-natal studies in rats. Progeny of dams receiving oral (gavage) dose levels of 50 mg/kg (1.6 times the MRHD) or greater had decreased weights, and pup survival was decreased early in lactation at 80 mg/kg (2.6 times the MRHD).

Nursing Mothers Risk Summary

Tramadol hydrochloride extended-release tablets are not recommended for obstetrical preoperative medication or for post-delivery analgesia in nursing mothers because its safety in infants and newborns has not been studied. Tramadol and its metabolite, O-desmethyl tramadol (M1), are present in human milk. There is no information on the effects of the drug on the breastfed infant or the effects of the drug on milk production. The M1 metabolite is more potent than tramadol in mu opioid receptor binding [see CLINICAL PHARMACOLOGY ]. Published studies have reported tramadol and M1 in colostrum with administration of tramadol to nursing mothers in the early post-partum period. Women who are ultra-rapid metabolizers of tramadol may have higher than expected serum levels of M1, potentially leading to higher levels of M1 in breast milk that can be dangerous in their breastfed infants. In women with normal tramadol metabolism, the amount of tramadol secreted into human milk is low and dose-dependent. Because of the potential for serious adverse reactions, including excess sedation and respiratory depression in a breastfed infant, advise patients that breastfeeding is not recommended during treatment with tramadol hydrochloride extended-release tablets.

Clinical Considerations

Monitor infants exposed to tramadol hydrochloride extended-release tablets through breast milk for excess sedation and respiratory depression. Withdrawal symptoms can occur in breastfed infants when maternal administration of an opioid analgesic is stopped, or when breast-feeding is stopped.

Data

Following a single IV 100 mg dose of tramadol, the cumulative excretion in breast milk within 16 hours post dose was 100 mcg of tramadol (0.1% of the maternal dose) and 27 mcg of M1.

Pediatric Use

The safety and effectiveness of tramadol hydrochloride extended-release tablets in pediatric patients have not been established. Life-threatening respiratory depression and death have occurred in children who received tramadol [ see WARNINGS ]. In some of the reported cases, these events followed tonsillectomy and/or adenoidectomy, and one of the children had evidence of being an ultra-rapid metabolizer of tramadol (i.e., multiple copies of the gene for cytochrome P450 isoenzyme 2D6 or high morphine concentrations). Children with sleep apnea may be particularly sensitive to the respiratory depressant effects of tramadol. Because of the risk of life-threatening respiratory depression and death: Tramadol hydrochloride extended-release tablets are contraindicated for all children younger than 12 years of age [ see CONTRAINDICATIONS ]. Tramadol hydrochloride extended-release tablets are contraindicated for post-operative management in pediatric patients younger than 18 years of age following tonsillectomy and/or adenoidectomy [ see CONTRAINDICATIONS ]. Avoid the use of tramadol hydrochloride extended-release tablets in adolescents 12 to 18 years of age who have other risk factors that may increase their sensitivity to the respiratory depressant effects of tramadol unless the benefits outweigh the risks. Risk factors include conditions associated with hypoventilation, such as postoperative status, obstructive sleep apnea, obesity, severe pulmonary disease, neuromuscular disease, and concomitant use of other medications that cause respiratory depression.

Geriatric Use In

12-week clinical trials, tramadol hydrochloride extended-release tablets were administered to 534 patients aged 65 years and older. Of those, 68 patients were 75 years of age and older. Comparable incidence rates of patients experiencing adverse events were observed for patients older than 65 years of age compared with younger patients (< 65 years of age), except constipation for which the incidence was higher in older patients. Tramadol hydrochloride extended-release tablets should be used with caution in patients older than 75 years of age [see CLINICAL PHARMACOLOGY , DOSAGE and ADMINISTRATION ] . Respiratory depression is the chief risk for elderly patients treated with opioids, and has occurred after large initial doses were administered to patients who were not opioid-tolerant or when opioids were coadministered with other agents that depress respiration. Titrate the dosage of tramadol hydrochloride extended-release tablets slowly in geriatric patients and frequently reevaluate the patient for signs of central nervous system and respiratory depression [see Warnings ] . Tramadol is known to be substantially excreted by the kidney, and the risk of adverse reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function.

Hyponatremia

Hyponatremia (serum sodium < 135 mmol/L) has been reported with the use of tramadol, and many cases are severe (sodium level < 120 mmol/L). Most cases of hyponatremia occurred in females over the age of 65 and within the first week of therapy. In some reports, hyponatremia resulted from the syndrome of inappropriate antidiuretic hormone secretion (SIADH). Monitor for signs and symptoms of hyponatremia (e.g., confusion, disorientation), during treatment with tramadol hydrochloride extended-release tablets, especially during initiation of therapy. If signs and symptoms of hyponatremia are present, initiate appropriate treatment (e.g., fluid restriction) and discontinue tramadol hydrochloride extended-release tablets [see DOSAGE and ADMINISTRATION: Safe Reduction or Discontinuation of Tramadol Hydrochloride Extended-Release Tablets ] .

Hypoglycemia

Cases of tramadol-associated hypoglycemia have been reported, some resulting in hospitalization. In most cases, patients had predisposing risk factors (e.g. diabetes). If hypoglycemia is suspected, monitor blood glucose levels and consider drug discontinuation as appropriate [see DOSAGE and ADMINISTRATION: Safe Reduction or Discontinuation of Tramadol Hydrochloride Extended-Release Tablets ] .

INTERACTIONS Table 2 includes clinically significant drug interactions with tramadol hydrochloride extended-release tablets.

Table

2: Clinically Significant Drug Interactions with Tramadol Hydrochloride Extended-Release Tablets Inhibitors of CYP2D6 Clinical Impact: The concomitant use of tramadol hydrochloride extended-release tablets and CYP2D6 inhibitors may result in an increase in the plasma concentration of tramadol and a decrease in the plasma concentration of M1, particularly when an inhibitor is added after a stable dose of tramadol hydrochloride extended-release tablet is achieved. Since M1 is a more potent μ-opioid agonist, decreased M1 exposure could result in decreased therapeutic effects, and may result in signs and symptoms of opioid withdrawal in patients who had developed physical dependence to tramadol. Increased tramadol exposure can result in increased or prolonged therapeutic effects and increased risk for serious adverse events including seizures and serotonin syndrome. After stopping a CYP2D6 inhibitor, as the effects of the inhibitor decline, the tramadol plasma concentration will decrease and the M1 plasma concentration will increase which could increase or prolong therapeutic effects but also increase adverse reactions related to opioid toxicity and may cause potentially fatal respiratory depression [see Clinical Pharmacology ( 12.3 )] . Intervention: If concomitant use of a CYP2D6 inhibitor is necessary, evaluate patients at frequent intervals for adverse reactions including opioid withdrawal, seizures, and serotonin syndrome. If a CYP2D6 inhibitor is discontinued, consider lowering tramadol hydrochloride extended-release tablets dosage until stable drug effects are achieved. Evaluate patients at frequent intervals for adverse events including respiratory depression and sedation.

Examples

Quinidine, fluoxetine, paroxetine and bupropion Inhibitors of CYP3A4 Clinical Impact: The concomitant use of tramadol hydrochloride extended-release tablets and CYP3A4 inhibitors can increase the plasma concentration of tramadol and may result in a greater amount of metabolism via CYP2D6 and greater levels of M1. Follow patients closely for increased risk of serious adverse events including seizures and serotonin syndrome, and adverse reactions related to opioid toxicity including potentially fatal respiratory depression, particularly when an inhibitor is added after a stable dose of tramadol hydrochloride extended-release tablets is achieved. After stopping a CYP3A4 inhibitor, as the effects of the inhibitor decline, the tramadol plasma concentration will decrease [see Clinical Pharmacology ( 12.3 )] , resulting in decreased opioid efficacy and possibly signs and symptoms of opioid withdrawal in patients who had developed physical dependence to tramadol. Intervention: If concomitant use is necessary, consider dosage reduction of tramadol hydrochloride extended-release tablets until stable drug effects are achieved. Inform patients and caregivers of this potential interaction, educate them on the signs and symptoms of seizures, serotonin syndrome, and signs of respiratory depression and sedation. Evaluate patients at frequent intervals for seizures and serotonin syndrome, and signs of respiratory depression and sedation. If a CYP3A4 inhibitor is discontinued, consider increasing the tramadol hydrochloride extended-release tablets dosage until stable drug effects are achieved and evaluate patients at frequent intervals for signs and symptoms of opioid withdrawal.

Examples

Macrolide antibiotics (e.g., erythromycin), azole-antifungal agents (e.g. ketoconazole), protease inhibitors (e.g., ritonavir) CYP3A4 Inducers Clinical Impact: The concomitant use of tramadol hydrochloride extended-release tablets and CYP3A4 inducers can decrease the plasma concentration of tramadol [see Clinical Pharmacology ( 12.3 )] , resulting in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence to tramadol, [see Warnings and Precautions ( 5.7 )] . After stopping a CYP3A4 inducer, as the effects of the inducer decline, the tramadol plasma concentration will increase [see Clinical Pharmacology ( 12.3 )] , which could increase or prolong both the therapeutic effects and adverse reactions, and may cause seizures and serotonin syndrome, and potentially fatal respiratory depression. Intervention: If concomitant use is necessary, consider increasing the tramadol hydrochloride extended-release tablets dosage until stable drug effects are achieved. Evaluate patients for signs of opioid withdrawal. If a CYP3A4 inducer is discontinued, consider tramadol hydrochloride extended-release tablets dosage reduction and evaluate patients at frequent intervals for seizures and serotonin syndrome, and signs of respiratory depression and sedation. Patients taking carbamazepine, a CYP3A4 inducer, may have a significantly reduced analgesic effect of tramadol. Because carbamazepine increases tramadol metabolism and because of the seizure risk associated with tramadol, concomitant administration of tramadol hydrochloride extended-release tablets and carbamazepine is not recommended. Examples: Rifampin, carbamazepine, phenytoin Benzodiazepines and Other Central Nervous System (CNS)

Depressants Clinical

Impact: Due to additive pharmacologic effect, the concomitant use of benzodiazepines or other CNS depressants, including alcohol, can increase the risk of hypotension, respiratory depression, profound sedation, coma, and death .[see Warnings and Precautions ( 5.3 )]. Intervention: Reserve concomitant prescribing of these drugs for use in patients for whom alternative treatment options are inadequate. Limit dosages and durations to the minimum required. Inform patients and caregivers of this potential interaction and educate them on the signs and symptoms of respiratory depression (including sedation). If concomitant use is warranted, consider recommending or prescribing an opioid overdose reversal agent [ see Dosage and Administration ( 2.2 ), Warnings and Precautions ( 5.1 , 5.2 , 5.3 )]. Examples: Benzodiazepines and other sedatives/hypnotics, anxiolytics, tranquilizers, muscle relaxants, general anesthetics, antipsychotics, gabapentinoids (gabapentin or pregabalin), other opioids, alcohol.

Serotonergic Drugs Clinical

Impact: The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome .[see Warnings and Precautions ( 5.9 )]. Intervention: If concomitant use is warranted, frequently evaluate the patient, particularly during treatment initiation and dose adjustment. Discontinue tramadol hydrochloride extended-release tablets if serotonin syndrome is suspected. Examples: Selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), triptans, 5-HT3 receptor antagonists, drugs that affect the serotonin neurotransmitter system (e.g., mirtazapine, trazodone, tramadol), certain muscle relaxants (i.e., cyclobenzaprine, metaxalone), monoamine oxidase (MAO) inhibitors (those intended to treat psychiatric disorders and also others, such as linezolid and intravenous methylene blue).

Monoamine Oxidase

Inhibitors (MAOIs)

Clinical

Impact: MAOI interactions with opioids may manifest as serotonin syndrome [see Warnings and Precautions ( 5.3 )] or opioid toxicity (e.g., respiratory depression, coma) [see Warnings and Precautions ( 5.2 )]. Intervention: Do not use tramadol hydrochloride extended-release tablets in patients taking MAOIs or within 14 days of stopping such treatment. Examples: phenelzine, tranylcypromine, linezolid Mixed Agonist/Antagonist and Partial Agonist Opioid Analgesics Clinical Impact: May reduce the analgesic effect of tramadol hydrochloride extended-release tablets and/or precipitate withdrawal symptoms. Intervention: Avoid concomitant use. Examples: butorphanol, nalbuphine, pentazocine, buprenorphine Muscle Relaxants Clinical Impact: Tramadol may enhance the neuromuscular blocking action of skeletal muscle relaxants and produce an increased degree of respiratory depression. Intervention: Because respiratory depression may be greater than otherwise expected, decrease the dosage of tramadol hydrochloride extended-release tablets and/or the muscle relaxant as necessary. Due to the risk of respiratory depression with concomitant use of skeletal muscle relaxants and opioids, consider recommending or prescribing an opioid overdose reversal agent [see Dosage and Administration ( 2.2 ), Warnings and Precautions ( 5.2 , 5.3 )]. Examples: cyclobenzaprine, metaxalone Diuretics Clinical Impact: Opioids can reduce the efficacy of diuretics by inducing the release of antidiuretic hormone. Intervention: Evaluate patients for signs of diminished diuresis and/or effects on blood pressure and increase the dosage of the diuretic as needed.

Anticholinergic Drugs Clinical

Impact: The concomitant use of anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Intervention: Evaluate patients for signs of urinary retention or reduced gastric motility when tramadol hydrochloride extended-release tablets are used concomitantly with anticholinergic drugs.

Digoxin Clinical

Impact: Post-marketing surveillance of tramadol has revealed rare reports of digoxin toxicity. Intervention: Evaluate patients at frequent intervals for signs of digoxin toxicity and adjust the dosage of digoxin as needed.

Warfarin Clinical

Impact: Post-marketing surveillance of tramadol has revealed rare reports of alteration of warfarin effect, including elevation of prothrombin times. Intervention: Frequently reevaluate the prothrombin time of patients on warfarin for signs of an interaction and adjust the dosage of warfarin as needed.

• Mixed Agonist/Antagonist and Partial Agonist Opioid Analgesics : Avoid use with tramadol hydrochloride extended-release tablets because they may reduce analgesic effect of tramadol hydrochloride extended-release tablets or precipitate withdrawal symptoms. ( 5.18 , 7 )