PREGABALIN: 102,360 Adverse Event Reports & Safety Profile

Pregabalin is described chemically as ( S )-3-(aminomethyl)-5-methylhexanoic acid. The molecular formula is C 8 H 17 NO 2 and the molecular weight is 159.23. The chemical structure of pregabalin is: Pregabalin is a white to off-white, crystalline solid with a pK a1 of 4.2 and a pK a2 of 10.6. It is freely soluble in water and both basic and acidic aqueous solutions. The log of the partition coefficient (n-octanol/0.05M phosphate buffer) at pH 7.4 is -1.35. LYRICA (pregabalin) Capsules are administered orally and are supplied as imprinted hard-shell capsules containing 25, 50, 75, 100, 150, 200, 225, and 300 mg of pregabalin, along with cornstarch, lactose monohydrate, and talc as inactive ingredients. The capsule shells contain gelatin and titanium dioxide. In addition, the orange capsule shells contain red iron oxide and the white capsule shells contain colloidal silicon dioxide and sodium lauryl sulfate. Colloidal silicon dioxide is a manufacturing aid that may or may not be present in the capsule shells. The imprinting ink contains black iron oxide, potassium hydroxide, propylene glycol, and shellac. LYRICA (pregabalin) oral solution, 20 mg/mL, is administered orally and is supplied as a clear, colorless solution contained in a 16 fluid ounce white HDPE bottle with a polyethylene-lined closure. The oral solution contains 20 mg/mL of pregabalin, along with artificial strawberry #11545, dibasic sodium phosphate anhydrous, methylparaben, monobasic sodium phosphate anhydrous, propylparaben, purified water, and sucralose as inactive ingredients.

Pregabalin Structural

Formula

AND USAGE Pregabalin capsules are indicated for:Pregabalin capsules are indicated for:

• Management of neuropathic pain associated with diabetic peripheral neuropathy
• Management of postherpetic neuralgia
• Adjunctive therapy for the treatment of partial-onset seizures in patients 17 years of age and older
• Management of fibromyalgia
• Management of neuropathic pain associated with spinal cord injury Pediatric use information is approved for Pfizer’s LYRICA (pregabalin) Capsules and Oral Solution products. However, due to Pfizer’s marketing exclusivity rights, this drug product is not labeled with that pediatric information. Pregabalin capsules are indicated for: Neuropathic pain associated with diabetic peripheral neuropathy (DPN) ( 1 ) Postherpetic neuralgia (PHN) ( 1 ) Adjunctive therapy for the treatment of partial onset seizures in patients 17 years of age and older ( 1 ) Fibromyalgia ( 1 ) Neuropathic pain associated with spinal cord injury ( 1 )

AND ADMINISTRATION For adult indications, begin dosing at 150 mg/day. For partial-onset seizure dosing in pediatric patients 1 month of age and older, refer to section 2.4. ( 2.2 , 2.3 , 2.4 , 2.5 , 2.6 ) Dosing recommendations: INDICATION Dosing Regimen Maximum Dose DPN Pain ( 2.2 ) 3 divided doses per day 300 mg/day within 1 week PHN ( 2.3 ) 2 or 3 divided doses per day 300 mg/day within 1 week. Maximum dose of 600 mg/day.

Adjunctive

Therapy for Partial-Onset Seizures in Pediatric and Adult Patients Weighing 30 kg or More ( 2.4 ) 2 or 3 divided doses per day Maximum dose of 600 mg/day.

Adjunctive

Therapy for Partial-Onset Seizures in Pediatric Patients Weighing Less than 30 kg ( 2.4 ) 1 month to less than 4 years : 3 divided doses per day 4 years and older : 2 or 3 divided doses per day 14 mg/kg/day. Fibromyalgia ( 2.5 ) 2 divided doses per day 300 mg/day within 1 week. Maximum dose of 450 mg/day.

Neuropathic Pain

Associated with Spinal Cord Injury ( 2.6 ) 2 divided doses per day 300 mg/day within 1 week. Maximum dose of 600 mg/day. Dose should be adjusted in adult patients with reduced renal function. ( 2.7 )

2.1 Important Administration Instructions Pregabalin capsules are given orally with or without food. When discontinuing pregabalin, taper gradually over a minimum of 1 week. <span class="opacity-50 text-xs">[see Warnings and Precautions (5.6) ]</span>. Because pregabalin is eliminated primarily by renal excretion, adjust the dose in adult patients with reduced renal function <span class="opacity-50 text-xs">[see Dosage and Administration (2.7) ]</span>.

2.2 Neuropathic Pain Associated with Diabetic Peripheral Neuropathy in Adults The maximum recommended dose of pregabalin capsule is 100 mg three times a day (300 mg/day) in patients with creatinine clearance of at least 60 mL/min. Begin dosing at 50 mg three times a day (150 mg/day). The dose may be increased to 300 mg/day within 1 week based on efficacy and tolerability. Although pregabalin was also studied at 600 mg/day, there is no evidence that this dose confers additional significant benefit and this dose was less well tolerated. In view of the dose-dependent adverse reactions, treatment with doses above 300 mg/day is not recommended <span class="opacity-50 text-xs">[see Adverse Reactions (6.1) ]</span> .

2.3 Postherpetic Neuralgia in Adults The recommended dose of pregabalin capsule is 75 to 150 mg two times a day, or 50 to 100 mg three times a day (150 to 300 mg/day) in patients with creatinine clearance of at least 60 mL/min. Begin dosing at 75 mg two times a day, or 50 mg three times a day (150 mg/day). The dose may be increased to 300 mg/day within 1 week based on efficacy and tolerability. Patients who do not experience sufficient pain relief following 2 to 4 weeks of treatment with 300 mg/day, and who are able to tolerate pregabalin, may be treated with up to 300 mg two times a day, or 200 mg three times a day (600 mg/day). In view of the dose-dependent adverse reactions and the higher rate of treatment discontinuation due to adverse reactions, reserve dosing above 300 mg/day for those patients who have on-going pain and are tolerating 300 mg daily <span class="opacity-50 text-xs">[see Adverse Reactions (6.1) ]</span> .

2.3 Postherpetic Neuralgia in Adults The recommended dose of pregabalin capsule is 75 to 150 mg two times a day, or 50 to 100 mg three times a day (150 to 300 mg/day) in patients with creatinine clearance of at least 60 mL/min. Begin dosing at 75 mg two times a day, or 50 mg three times a day (150 mg/day). The dose may be increased to 300 mg/day within 1 week based on efficacy and tolerability. Patients who do not experience sufficient pain relief following 2 to 4 weeks of treatment with 300 mg/day, and who are able to tolerate pregabalin, may be treated with up to 300 mg two times a day, or 200 mg three times a day (600 mg/day). In view of the dose-dependent adverse reactions and the higher rate of treatment discontinuation due to adverse reactions, reserve dosing above 300 mg/day for those patients who have on-going pain and are tolerating 300 mg daily <span class="opacity-50 text-xs">[see Adverse Reactions (6.1) ]</span> .

2.4 Adjunctive Therapy for Partial-Onset Seizures in Patients 17 Years of Age and Older The recommended dosage for adult and pediatric patients 1 month of age and older is included in Table 1. Administer the total daily dosage orally in two or three divided doses as indicated in Table 1. In pediatric patients, the recommended dosing regimen is dependent upon body weight. Based on clinical response and tolerability, dosage may be increased, approximately weekly.

Table

1.

Recommended

Dosage for Adult and Pediatric Patients 1 Month and Older Age and Body Weight Recommended Initial Dosage Recommended Maximum Dosage Frequency of Administration Adults (17 years and older) 150 mg/day 600 mg/day 2 or 3 divided doses Pediatric patients weighing 30 kg or more 2.5 mg/kg/day 10 mg/kg/day (not to exceed 600 mg/day) 2 or 3 divided doses Pediatric patients weighing less than 30 kg 3.5 mg/kg/day 14 mg/kg/day 1 month to less than 4 years of age: 3 divided doses 4 years of age and older: 2 or 3 divided doses Both the efficacy and adverse event profiles of pregabalin have been shown to be dose-related. The effect of dose escalation rate on the tolerability of pregabalin has not been formally studied. The efficacy of adjunctive pregabalin in patients taking gabapentin has not been evaluated in controlled trials. Consequently, dosing recommendations for the use of pregabalin with gabapentin cannot be offered.

2.5 Management of Fibromyalgia in Adults The recommended dose of pregabalin capsules for fibromyalgia is 300 to 450 mg/day. Begin dosing at 75 mg two times a day (150 mg/day). The dose may be increased to 150 mg two times a day (300 mg/day) within 1 week based on efficacy and tolerability. Patients who do not experience sufficient benefit with 300 mg/day may be further increased to 225 mg two times a day (450 mg/day). Although pregabalin was also studied at 600 mg/day, there is no evidence that this dose confers additional benefit and this dose was less well tolerated. In view of the dose-dependent adverse reactions, treatment with doses above 450 mg/day is not recommended <span class="opacity-50 text-xs">[see Adverse Reactions (6.1) ]</span> .

2.6 Neuropathic Pain Associated with Spinal Cord Injury in Adults The recommended dose range of pregabalin capsules for the treatment of neuropathic pain associated with spinal cord injury is 150 to 600 mg/day. The recommended starting dose is 75 mg two times a day (150 mg/day). The dose may be increased to 150 mg two times a day (300 mg/day) within 1 week based on efficacy and tolerability. Patients who do not experience sufficient pain relief after 2 to 3 weeks of treatment with 150 mg two times a day and who tolerate pregabalin may be treated with up to 300 mg two times a day <span class="opacity-50 text-xs">[see Clinical Studies (14.5) ]</span> .

2.7 Dosing for Adult Patients with Renal Impairment In view of dose-dependent adverse reactions and since pregabalin is eliminated primarily by renal excretion, adjust the dose in adult patients with reduced renal function. The use of pregabalin in pediatric patients with compromised renal function has not been studied. Base the dose adjustment in patients with renal impairment on creatinine clearance (CLcr), as indicated in Table 2. To use this dosing table, an estimate of the patient&apos;s CLcr in mL/min is needed. CLcr in mL/min may be estimated from serum creatinine (mg/dL) determination using the Cockcroft and Gault equation: Next, refer to the Dosage and Administration section to determine the recommended total daily dose based on indication, for a patient with normal renal function (CLcr greater than or equal to 60 mL/min). Then refer to Table 2 to determine the corresponding renal adjusted dose. (For example: A patient initiating pregabalin therapy for postherpetic neuralgia with normal renal function (CLcr greater than or equal to 60 mL/min), receives a total daily dose of 150 mg/day pregabalin. Therefore, a renal impaired patient with a CLcr of 50 mL/min would receive a total daily dose of 75 mg/day pregabalin administered in two or three divided doses.) For patients undergoing hemodialysis, adjust the pregabalin daily dose based on renal function. In addition to the daily dose adjustment, administer a supplemental dose immediately following every 4-hour hemodialysis treatment (see Table 2).

Table

2.

Pregabalin Dosage Adjustment

Based on Renal Function TID= Three divided doses; BID = Two divided doses; QD = Single daily dose. * Total daily dose (mg/day) should be divided as indicated by dose regimen to provide mg/dose. † Supplementary dose is a single additional dose.

Creatinine

Clearance (CLcr) (mL/min)

Total Pregabalin Daily

Dose (mg/day)* Dose Regimen Greater than or equal to 60 150 300 450 600 BID or TID 30–60 75 150 225 300 BID or TID 15–30 25–50 75 100–150 150 QD or BID Less than 15 25 25–50 50–75 75 QD Supplementary dosage following hemodialysis (mg)† Patients on the 25 mg QD regimen: take one supplemental dose of 25 mg or 50 mg Patients on the 25–50 mg QD regimen: take one supplemental dose of 50 mg or 75 mg Patients on the 50–75 mg QD regimen: take one supplemental dose of 75 mg or 100 mg Patients on the 75 mg QD regimen: take one supplemental dose of 100 mg or 150 mg Cockcroft and Gault equation

Pregabalin capsules are contraindicated in patients with known hypersensitivity to pregabalin or any of its components. Angioedema and hypersensitivity reactions have occurred in patients receiving pregabalin therapy [see Warnings and Precautions ( Error! Hyperlink reference not valid. )] .

• Known hypersensitivity to pregabalin or any of its components. ( Error! Hyperlink reference not valid. )

REACTIONS The following serious adverse reactions are described elsewhere in the labeling:

• Angioedema [see Warnings and Precautions ( Error! Hyperlink reference not valid. )]
• Hypersensitivity [see Warnings and Precautions ( Error! Hyperlink reference not valid. )]
• Suicidal Behavior and Ideation [see Warnings and Precautions ( Error! Hyperlink reference not valid. )]
• Respiratory Depression [see Warnings and Precautions ( Error! Hyperlink reference not valid. )]
• Dizziness and Somnolence [see Warnings and Precautions ( Error! Hyperlink reference not valid. )]
• Increased Risk of Adverse Reactions with Abrupt or Rapid Discontinuation [see Warnings and Precautions ( Error! Hyperlink reference not valid. )]
• Peripheral Edema [see Warnings and Precautions ( Error! Hyperlink reference not valid. )]
• Weight Gain [see Warnings and Precautions ( Error! Hyperlink reference not valid. )]
• Tumorigenic Potential [see Warnings and Precautions ( Error! Hyperlink reference not valid. )]
• Ophthalmological Effects [see Warnings and Precautions ( Error! Hyperlink reference not valid. )]
• Creatine Kinase Elevations [see Warnings and Precautions ( Error! Hyperlink reference not valid. )]
• Decreased Platelet Count [see Warnings and Precautions ( Error! Hyperlink reference not valid. )]
• PR Interval Prolongation [see Warnings and Precautions ( Error! Hyperlink reference not valid. )] Most common adverse reactions (greater than or equal to 5% and twice placebo) in adults are dizziness, somnolence, dry mouth, edema, blurred vision, weight gain, and thinking abnormal (primarily difficulty with concentration/attention). ( Error! Hyperlink reference not valid. ) Most common adverse reactions (greater than or equal to 5% and twice placebo) in pediatric patients for the treatment of partial-onset seizures are increased weight and increased appetite. ( Error! Hyperlink reference not valid. ) To report SUSPECTED ADVERSE REACTIONS, contact Hetero Labs Limited at 1-866-495-1995 or FDA at 1-800-FDA-1088 orwww.fda.gov/medwatch.

6.1 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. In all controlled and uncontrolled trials across various patient populations during the premarketing development of pregabalin capsules, more than 10,000 patients have received pregabalin capsules.

Approximately

5,000 patients were treated for 6 months or more, over 3,100 patients were treated for 1 year or longer, and over 1,400 patients were treated for at least 2 years.

Adverse Reactions Most Commonly

Leading to Discontinuation in All Premarketing Controlled Clinical Studies In premarketing controlled trials of all adult populations combined, 14% of patients treated with pregabalin capsules and 7% of patients treated with placebo discontinued prematurely due to adverse reactions. In the pregabalin capsules treatment group, the adverse reactions most frequently leading to discontinuation were dizziness (4%) and somnolence (4%). In the placebo group, 1% of patients withdrew due to dizziness and less than 1% withdrew due to somnolence. Other adverse reactions that led to discontinuation from controlled trials more frequently in the pregabalin capsules group compared to the placebo group were ataxia, confusion, asthenia, thinking abnormal, blurred vision, incoordination, and peripheral edema (1% each).

Most Common Adverse

Reactions in All Controlled Clinical Studies in Adults In premarketing controlled trials of all adult patient populations combined (including DPN, PHN, and adult patients with partial-onset seizures), dizziness, somnolence, dry mouth, edema, blurred vision, weight gain, and "thinking abnormal" (primarily difficulty with concentration/attention) were more commonly reported by subjects treated with pregabalin capsules than by subjects treated with placebo (greater than or equal to 5% and twice the rate of that seen in placebo).

Controlled

Studies with Neuropathic Pain Associated with Diabetic Peripheral Neuropathy Adverse Reactions Leading to Discontinuation In clinical trials in adults with neuropathic pain associated with diabetic peripheral neuropathy, 9% of patients treated with pregabalin capsules and 4% of patients treated with placebo discontinued prematurely due to adverse reactions. In the pregabalin capsules treatment group, the most common reasons for discontinuation due to adverse reactions were dizziness (3%) and somnolence (2%). In comparison, less than 1% of placebo patients withdrew due to dizziness and somnolence. Other reasons for discontinuation from the trials, occurring with greater frequency in the pregabalin capsules group than in the placebo group, were asthenia, confusion, and peripheral edema. Each of these events led to withdrawal in approximately 1% of patients.

Most Common Adverse Reactions Table

4 lists all adverse reactions, regardless of causality, occurring in greater than or equal to 1% of patients with neuropathic pain associated with diabetic neuropathy in the combined pregabalin capsules group for which the incidence was greater in this combined pregabalin capsules group than in the placebo group. A majority of pregabalin-treated patients in clinical studies had adverse reactions with a maximum intensity of "mild" or "moderate”.

Table

4.

Adverse Reaction

Incidence in Controlled Trials in Neuropathic Pain Associated with Diabetic Peripheral Neuropathy Body systemPreferred term 75 mg/day [N=77] % 150 mg/day [N=212] % 300 mg/day [N=321] % 600 mg/day [N=369] % All PGB* [N=979] % Placebo [N=459] % Body as a whole Asthenia 4 2 4 7 5 2 Accidental injury 5 2 2 6 4 3 Back pain 0 2 1 2 2 0 Chest pain 4 1 1 2 2 1 Face edema 0 1 1 2 1 0 Digestive system Dry mouth 3 2 5 7 5 1 Constipation 0 2 4 6 4 2 Flatulence 3 0 2 3 2 1 Metabolic and nutritional disorders Peripheral edema 4 6 9 12 9 2 Weight gain 0 4 4 6 4 0 Edema 0 2 4 2 2 0 Hypoglycemia 1 3 2 1 2 1 Nervous system Dizziness 8 9 23 29 21 5 Somnolence 4 6 13 16 12 3 Neuropathy 9 2 2 5 4 3 Ataxia 6 1 2 4 3 1 Vertigo 1 2 2 4 3 1 Confusion 0 1 2 3 2 1 Euphoria 0 0 3 2 2 0 Incoordination 1 0 2 2 2 0 Thinking abnormal † 1 0 1 3 2 0 Tremor 1 1 1 2 1 0 Abnormal gait 1 0 1 3 1 0 Amnesia 3 1 0 2 1 0 Nervousness 0 1 1 1 1 0 Respiratory system Dyspnea 3 0 2 2 2 1 Special senses Blurry vision ‡ 3 1 3 6 4 2 Abnormal vision 1 0 1 1 1 0 * PGB: pregabalin † Thinking abnormal primarily consists of events related to difficulty with concentration/attention but also includes events related to cognition and language problems and slowed thinking. ‡ Investigator term; summary level term is amblyopia Controlled Studies in Postherpetic Neuralgia Adverse Reactions Leading to Discontinuation In clinical trials in adults with postherpetic neuralgia, 14% of patients treated with pregabalin capsules and 7% of patients treated with placebo discontinued prematurely due to adverse reactions. In the pregabalin capsules treatment group, the most common reasons for discontinuation due to adverse reactions were dizziness (4%) and somnolence (3%). In comparison, less than 1% of placebo patients withdrew due to dizziness and somnolence. Other reasons for discontinuation from the trials, occurring in greater frequency in the pregabalin capsules group than in the placebo group, were confusion (2%), as well as peripheral edema, asthenia, ataxia, and abnormal gait (1% each).

Most Common Adverse Reactions Table

5 lists all adverse reactions, regardless of causality, occurring in greater than or equal to 1% of patients with neuropathic pain associated with postherpetic neuralgia in the combined pregabalin capsules group for which the incidence was greater in this combined pregabalin capsules group than in the placebo group. In addition, an event is included, even if the incidence in the all pregabalin capsules group is not greater than in the placebo group, if the incidence of the event in the 600 mg/day group is more than twice that in the placebo group. A majority of pregabalin-treated patients in clinical studies had adverse reactions with a maximum intensity of "mild" or "moderate". Overall, 12.4% of all pregabalin-treated patients and 9.0% of all placebo-treated patients had at least one severe event while 8% of pregabalin-treated patients and 4.3% of placebo-treated patients had at least one severe treatment-related adverse event.

Table

5.

Adverse Reaction

Incidence in Controlled Trials in Neuropathic Pain Associated with Postherpetic Neuralgia Body system Preferred term 75 mg/d [N=84] % 150 mg/d [N=302] % 300 mg/d [N=312] % 600 mg/d [N=154] % All PGB*[N=852] % Placebo [N=398] % Body as a whole Infection 14 8 6 3 7 4 Headache 5 9 5 8 7 5 Pain 5 4 5 5 5 4 Accidental injury 4 3 3 5 3 2 Flu syndrome 1 2 2 1 2 1 Face edema 0 2 1 3 2 1 Digestive system Dry mouth 7 7 6 15 8 3 Constipation 4 5 5 5 5 2 Flatulence 2 1 2 3 2 1 Vomiting 1 1 3 3 2 1 Metabolic and nutritional disorders Peripheral edema 0 8 16 16 12 4 Weight gain 1 2 5 7 4 0 Edema 0 1 2 6 2 1 Musculoskeletal system Myasthenia 1 1 1 1 1 0 Nervous system Dizziness 11 18 31 37 26 9 Somnolence 8 12 18 25 16 5 Ataxia 1 2 5 9 5 1 Abnormal gait 0 2 4 8 4 1 Confusion 1 2 3 7 3 0 Thinking abnormal † 0 2 1 6 2 2 Incoordination 2 2 1 3 2 0 Amnesia 0 1 1 4 2 0 Speech disorder 0 0 1 3 1 0 Respiratory system Bronchitis 0 1 1 3 1 1 Special senses Blurry vision ‡ 1 5 5 9 5 3 Diplopia 0 2 2 4 2 0 Abnormal vision 0 1 2 5 2 0 Eye Disorder 0 1 1 2 1 0 Urogenital System Urinary Incontinence 0 1 1 2 1 0 * PGB: pregabalin † Thinking abnormal primarily consists of events related to difficulty with concentration/attention but also includes events related to cognition and language problems and slowed thinking. ‡ Investigator term; summary level term is amblyopia Controlled Studies of Adjunctive Therapy for Partial-Onset Seizures in Adult Patients Adverse Reactions Leading to Discontinuation Approximately 15% of patients receiving pregabalin capsules and 6% of patients receiving placebo in trials of adjunctive therapy for partial-onset seizures discontinued prematurely due to adverse reactions. In the pregabalin capsules treatment group, the adverse reactions most frequently leading to discontinuation were dizziness (6%), ataxia (4%), and somnolence (3%). In comparison, less than 1% of patients in the placebo group withdrew due to each of these events. Other adverse reactions that led to discontinuation of at least 1% of patients in the pregabalin capsules group and at least twice as frequently compared to the placebo group were asthenia, diplopia, blurred vision, thinking abnormal, nausea, tremor, vertigo, headache, and confusion (which each led to withdrawal in 2% or less of patients).

Most Common Adverse Reactions Table

6 lists all dose-related adverse reactions occurring in at least 2% of all pregabalin capsules-treated patients. Dose-relatedness was defined as the incidence of the adverse event in the 600 mg/day group was at least 2% greater than the rate in both the placebo and 150 mg/day groups. In these studies, 758 patients received pregabalin capsules and 294 patients received placebo for up to 12 weeks. A majority of pregabalin-treated patients in clinical studies had adverse reactions with a maximum intensity of "mild" or "moderate”.

Table

6. Dose-related Adverse Reaction Incidence in Controlled Trials of Adjunctive Therapy for Partial-Onset Seizures in Adult Patients Body SystemPreferred Term 150 mg/d [N = 185] % 300 mg/d [N = 90] % 600 mg/d [N = 395] % All PGB * [N = 670] † % Placebo [N = 294] % Body as a Whole Accidental Injury 7 11 10 9 5 Pain 3 2 5 4 3 Digestive System Increased Appetite 2 3 6 5 1 Dry Mouth 1 2 6 4 1 Constipation 1 1 7 4 2 Metabolic and Nutritional Disorders Weight Gain 5 7 16 12 1 Peripheral Edema 3 3 6 5 2 Nervous System Dizziness 18 31 38 32 11 Somnolence 11 18 28 22 11 Ataxia 6 10 20 15 4 Tremor 3 7 11 8 4 Thinking Abnormal ‡ 4 8 9 8 2 Amnesia 3 2 6 5 2 Speech Disorder 1 2 7 5 1 Incoordination 1 3 6 4 1 Abnormal Gait 1 3 5 4 0 Twitching 0 4 5 4 1 Confusion 1 2 5 4 2 Myoclonus 1 0 4 2 0 Special Senses Blurred Vision § 5 8 12 10 4 Diplopia 5 7 12 9 4 Abnormal Vision 3 1 5 4 1 * PGB: pregabalin † Excludes patients who received the 50 mg dose in Study E1. ‡ Thinking abnormal primarily consists of events related to difficulty with concentration/attention but also includes events related to cognition and language problems and slowed thinking. § Investigator term; summary level term is amblyopia.

Controlled

Study of Adjunctive Therapy for Partial-Onset Seizures in Patients 4 to Less Than 17 Years of Age Adverse Reactions Leading to Discontinuation Approximately 2.5% of patients receiving pregabalin and no patients receiving placebo in trials of adjunctive therapy for partial-onset seizures discontinued prematurely due to adverse reactions. In the pregabalin treatment group, the adverse reactions leading to discontinuation were somnolence (3 patients), worsening of epilepsy (1 patient), and hallucination (1 patient).

Most Common Adverse Reactions Table

7 lists all dose-related adverse reactions occurring in at least 2% of all pregabalin capsules -treated patients. Dose-relatedness was defined as an incidence of the adverse event in the 10 mg/kg/day group that was at least 2% greater than the rate in both the placebo and 2.5 mg/kg/day groups. In this study, 201 patients received pregabalin and 94 patients received placebo for up to 12 weeks. A majority of pregabalin-treated patients in the clinical study had adverse reactions with a maximum intensity of "mild" or "moderate”.

Table

7. Dose-related Adverse Reaction Incidence in a Controlled Trial in Adjunctive Therapy for Partial-Onset Seizures in Patients 4 to Less Than 17 Years of Age Body System Preferred Term 2.5 mg/kg/day a [N=104] % 10 mg/kg/day b [N=97] % All PGB [N=201] % Placebo [N=94] % Gastrointestinal disorders Salivary hypersecretion 1 4 2 0 Investigations Weight increased 4 13 8 4 Metabolism and nutrition disorders Increased appetite 7 10 8 4 Nervous system disorders Somnolence 17 26 21 14 Abbreviations: N=number of patients; PGB = pregabalin. a. 2.5 mg/kg/day: Maximum dose 150 mg/day. Includes patients less than 30 kg for whom dose was adjusted to 3.5 mg/kg/day. b. 10 mg/kg/day: Maximum dose 600 mg/day. Includes patients less than 30 kg for whom dose was adjusted to 14 mg/kg/day.

Controlled

Study of Adjunctive Therapy for Partial-Onset Seizures in Patients 1 Month to Less Than 4 Years of Age Most Common Adverse Reactions Table 8 lists all dose-related adverse reactions occurring in at least 2% of all pregabalin capsules -treated patients. Dose-relatedness was defined as an incidence of the adverse event in the 14 mg/kg/day group that was at least 2% greater than the rate in both the placebo and 7 mg/kg/day groups. In this study, 105 patients received pregabalin and 70 patients received placebo for up to 14 days.

Table

8. Dose-related Adverse Reaction Incidence in a Controlled Trial in Adjunctive Therapy for Partial-Onset Seizures in Patients 1 Month to Less Than 4 Years of Age Body System Preferred Term 7 mg/kg/day [N=71] % 14 mg/kg/day [N=34] % All PGB [N=105] % Placebo [N=70] % Nervous system disorders Somnolence* 13 21 15 9 Infections and infestations Pneumonia 1 9 4 0 Viral infection 3 6 4 3 Abbreviations: N=number of patients; PGB=pregabalin. * includes related terms including lethargy, sluggishness, and hypersomnia.

Controlled

Studies with Fibromyalgia Adverse Reactions Leading to Discontinuation In clinical trials of patients with fibromyalgia, 19% of patients treated with pregabalin (150 mg to 600 mg/day) and 10% of patients treated with placebo discontinued prematurely due to adverse reactions. In the pregabalin treatment group, the most common reasons for discontinuation due to adverse reactions were dizziness (6%) and somnolence (3%). In comparison, less than 1% of placebo-treated patients withdrew due to dizziness and somnolence. Other reasons for discontinuation from the trials, occurring with greater frequency in the pregabalin treatment group than in the placebo treatment group, were fatigue, headache, balance disorder, and weight increased. Each of these adverse reactions led to withdrawal in approximately 1% of patients.

Most Common Adverse Reactions Table

9 lists all adverse reactions, regardless of causality, occurring in greater than or equal to 2% of patients with fibromyalgia in the ‘all pregabalin’ treatment group for which the incidence was greater than in the placebo treatment group. A majority of pregabalin-treated patients in clinical studies experienced adverse reactions with a maximum intensity of "mild" or "moderate".

Table

9.

Adverse Reaction

Incidence in Controlled Trials in Fibromyalgia System Organ Class Preferred term 150 mg/d [N=132] % 300 mg/d [N=502] % 450 mg/d [N=505] % 600 mg/d [N=378] % All PGB* [N=1,517] % Placebo [N=505] % Ear and Labyrinth Disorders Vertigo 2 2 2 1 2 0 Eye Disorders Vision blurred 8 7 7 12 8 1 Gastrointestinal Disorders Dry mouth 7 6 9 9 8 2 Constipation 4 4 7 10 7 2 Vomiting 2 3 3 2 3 2 Flatulence 1 1 2 2 2 1 Abdominal distension 2 2 2 2 2 1 General Disorders and Administrative Site Conditions Fatigue 5 7 6 8 7 4 Edema peripheral 5 5 6 9 6 2 Chest pain 2 1 1 2 2 1 Feeling abnormal 1 3 2 2 2 0 Edema 1 2 1 2 2 1 Feeling drunk 1 2 1 2 2 0 Infections and Infestations Sinusitis 4 5 7 5 5 4 Investigations Weight increased 8 10 10 14 11 2 Metabolism and Nutrition Disorders Increased appetite 4 3 5 7 5 1 Fluid retention 2 3 3 2 2 1 Musculoskeletal and Connective Tissue Disorders Arthralgia 4 3 3 6 4 2 Muscle spasms 2 4 4 4 4 2 Back pain 2 3 4 3 3 3 Nervous System Disorders Dizziness 23 31 43 45 38 9 Somnolence 13 18 22 22 20 4 Headache 11 12 14 10 12 12 Disturbance in attention 4 4 6 6 5 1 Balance disorder 2 3 6 9 5 0 Memory impairment 1 3 4 4 3 0 Coordination abnormal 2 1 2 2 2 1 Hypoesthesia 2 2 3 2 2 1 Lethargy 2 2 1 2 2 0 Tremor 0 1 3 2 2 0 Psychiatric Disorders Euphoric Mood 2 5 6 7 6 1 Confusional state 0 2 3 4 3 0 Anxiety 2 2 2 2 2 1 Disorientation 1 0 2 1 2 0 Depression 2 2 2 2 2 2 Respiratory, Thoracic and Mediastinal Disorders Pharyngolaryngeal pain 2 1 3 3 2 2 * PGB: pregabalin Controlled Studies in Neuropathic Pain Associated with Spinal Cord Injury Adverse Reactions Leading to Discontinuation In clinical trials of adults with neuropathic pain associated with spinal cord injury, 13% of patients treated with pregabalin and 10% of patients treated with placebo discontinued prematurely due to adverse reactions. In the pregabalin treatment group, the most common reasons for discontinuation due to adverse reactions were somnolence (3%) and edema (2%). In comparison, none of the placebo-treated patients withdrew due to somnolence and edema. Other reasons for discontinuation from the trials, occurring with greater frequency in the pregabalin treatment group than in the placebo treatment group, were fatigue and balance disorder. Each of these adverse reactions led to withdrawal in less than 2% of patients.

Most Common Adverse Reactions Table

10 lists all adverse reactions, regardless of causality, occurring in greater than or equal to 2% of patients for which the incidence was greater than in the placebo treatment group with neuropathic pain associated with spinal cord injury in the controlled trials. A majority of pregabalin-treated patients in clinical studies experienced adverse reactions with a maximum intensity of "mild" or "moderate".

Table

10.

Adverse Reaction

Incidence in Controlled Trials in Neuropathic Pain Associated with Spinal Cord Injury System Organ Class Preferred term PGB* (N=182) Placebo (N=174) % % Ear and labyrinth disorders Vertigo 2.7

1.1 Eye disorders Vision blurred 6.6

1.1 Gastrointestinal disorders Dry mouth 11.0

2.9 Constipation 8.2

5.7 Nausea 4.9

4.0 Vomiting 2.7

1.1 General disorders and administration site conditions Fatigue 11.0

4.0 Edema peripheral 10.4

5.2 Edema 8.2

1.1 Pain 3.3

1.1 Infections and infestations Nasopharyngitis 8.2

4.6 Investigations Weight increased 3.3

1.1 Blood creatine phosphokinase increased 2.7 0 Musculoskeletal and connective tissue disorders Muscular weakness 4.9

1.7 Pain in extremity 3.3

2.3 Neck pain 2.7

1.1 Back pain 2.2

1.7 Joint swelling 2.2 0 Nervous system disorders Somnolence 35.7

11.5 Dizziness 20.9

6.9 Disturbance in attention 3.8 0 Memory impairment 3.3

1.1 Paresthesia 2.2

0.6 Psychiatric disorders Insomnia 3.8

2.9 Euphoric mood 2.2

0.6 Renal and urinary disorders Urinary incontinence 2.7

1.1 Skin and subcutaneous tissue disorders Decubitus ulcer 2.7

1.1 Vascular disorders Hypertension 2.2

1.1 Hypotension 2.2 0 * PGB: Pregabalin Other Adverse Reactions Observed During the Clinical Studies of Pregabalin Capsules Following is a list of treatment-emergent adverse reactions reported by patients treated with pregabalin capsules during all clinical trials. The listing does not include those events already listed in the previous tables or elsewhere in labeling, those events for which a drug cause was remote, those events which were so general as to be uninformative, and those events reported only once which did not have a substantial probability of being acutely life-threatening. Events are categorized by body system and listed in order of decreasing frequency according to the following definitions: frequent adverse reactions are those occurring on one or more occasions in at least 1/100 patients; infrequent adverse reactions are those occurring in 1/100 to 1/1,000 patients; rare reactions are those occurring in fewer than 1/1,000 patients. Events of major clinical importance are described in the Warnings and Precautions section ( 5 ). Body as a Whole – Frequent : Abdominal pain, Allergic reaction, Fever, Infrequent : Abscess, Cellulitis, Chills, Malaise, Neck rigidity, Overdose, Pelvic pain, Photosensitivity reaction, Rare : Anaphylactoid reaction, Ascites, Granuloma, Hangover effect, Intentional Injury, Retroperitoneal Fibrosis, Shock Cardiovascular System – Infrequent : Deep thrombophlebitis, Heart failure, Hypotension, Postural hypotension, Retinal vascular disorder, Syncope; Rare : ST Depressed, Ventricular Fibrillation Digestive System – Frequent : Gastroenteritis, Increased appetite; Infrequent : Cholecystitis, Cholelithiasis, Colitis, Dysphagia, Esophagitis, Gastritis, Gastrointestinal hemorrhage, Melena, Mouth ulceration, Pancreatitis, Rectal hemorrhage, Tongue edema; Rare : Aphthous stomatitis, Esophageal Ulcer, Periodontal abscess Hemic and Lymphatic System – Frequent : Ecchymosis; Infrequent : Anemia, Eosinophilia, Hypochromic anemia, Leukocytosis, Leukopenia, Lymphadenopathy, Thrombocytopenia; Rare : Myelofibrosis, Polycythemia, Prothrombin decreased, Purpura, Thrombocythemia, Alanine aminotransferase increased, Aspartate aminotransferase increased Metabolic and Nutritional Disorders – Rare : Glucose Tolerance Decreased, Urate Crystalluria Musculoskeletal System – Frequent : Arthralgia, Leg cramps, Myalgia, Myasthenia; Infrequent : Arthrosis; Rare : Chondrodystrophy, Generalized Spasm Nervous System – Frequent : Anxiety, Depersonalization, Hypertonia, Hypoesthesia, Libido decreased, Nystagmus, Paresthesia, Sedation, Stupor, Twitching; Infrequent : Abnormal dreams, Agitation, Apathy, Aphasia, Circumoral paresthesia, Dysarthria, Hallucinations, Hostility, Hyperalgesia, Hyperesthesia, Hyperkinesia, Hypokinesia, Hypotonia, Libido increased, Myoclonus, Neuralgia; Rare : Addiction, Cerebellar syndrome, Cogwheel rigidity, Coma, Delirium, Delusions, Dysautonomia, Dyskinesia, Dystonia, Encephalopathy, Extrapyramidal syndrome, Guillain-Barré syndrome, Hypalgesia, Intracranial hypertension, Manic reaction, Paranoid reaction, Peripheral neuritis, Personality disorder, Psychotic depression, Schizophrenic reaction, Sleep disorder, Torticollis, Trismus Respiratory System – Rare : Apnea, Atelectasis, Bronchiolitis, Hiccup, Laryngismus, Lung edema, Lung fibrosis, Yawn Skin and Appendages – Frequent : Pruritus, Infrequent : Alopecia, Dry skin, Eczema, Hirsutism, Skin ulcer, Urticaria, Vesiculobullous rash; Rare : Angioedema, Exfoliative dermatitis, Lichenoid dermatitis, Melanosis, Nail Disorder, Petechial rash, Purpuric rash, Pustular rash, Skin atrophy, Skin necrosis, Skin nodule, Stevens-Johnson syndrome, Subcutaneous nodule Special senses – Frequent : Conjunctivitis, Diplopia, Otitis media, Tinnitus; Infrequent : Abnormality of accommodation, Blepharitis, Dry eyes, Eye hemorrhage, Hyperacusis, Photophobia, Retinal edema, Taste loss, Taste perversion; Rare : Anisocoria, Blindness, Corneal ulcer, Exophthalmos, Extraocular palsy, Iritis, Keratitis, Keratoconjunctivitis, Miosis, Mydriasis, Night blindness, Ophthalmoplegia, Optic atrophy, Papilledema, Parosmia, Ptosis, Uveitis Urogenital System – Frequent : Anorgasmia, Impotence, Urinary frequency, Urinary incontinence; Infrequent : Abnormal ejaculation, Albuminuria, Amenorrhea, Dysmenorrhea, Dysuria, Hematuria, Kidney calculus, Leukorrhea, Menorrhagia, Metrorrhagia, Nephritis, Oliguria, Urinary retention, Urine abnormality; Rare : Acute kidney failure, Balanitis, Bladder Neoplasm, Cervicitis, Dyspareunia, Epididymitis, Female lactation, Glomerulitis, Ovarian disorder, Pyelonephritis Comparison of Gender and Race The overall adverse event profile of pregabalin was similar between women and men. There are insufficient data to support a statement regarding the distribution of adverse experience reports by race.

6.2 Postmarketing Experience The following adverse reactions have been identified during postapproval use of pregabalin capsules. 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.

Nervous System

Disorders – Headache Gastrointestinal Disorders – Nausea, Diarrhea Reproductive System and Breast Disorders – Gynecomastia, Breast Enlargement Skin and subcutaneous tissue disorders – Bullous pemphigoid There are postmarketing reports of life-threatening or fatal respiratory depression in patients taking pregabalin capsules with opioids or other CNS depressants, or in the setting of underlying respiratory impairment. In addition, there are postmarketing reports of events related to reduced lower gastrointestinal tract function (e.g., intestinal obstruction, paralytic ileus, constipation) when pregabalin capsules were co-administered with medications that have the potential to produce constipation, such as opioid analgesics.

AND PRECAUTIONS Angioedema : Angioedema [e.g., swelling of the face, mouth (tongue, lips, and gums) and neck (throat and larynx)] can occur and may be associated with life-threatening respiratory compromise requiring emergency treatment. Discontinue pregabalin extended-release tablets immediately inpatients with these symptoms. ( 5.1 )

Hypersensitivity

Reactions : Hypersensitivity reactions (e.g., hives, dyspnea, and wheezing) can occur. Discontinue pregabalin extended-release tablets immediately in these patients. ( 5.2 )

Suicidal

Behavior and Ideation : Antiepileptic drugs, including pregabalin, the active ingredient in pregabalin extended-release tablets, increase the risk of suicidal thoughts or behavior. ( 5.3 ) Abrupt or rapid discontinuation may increase the risk for seizures. Withdrawal symptoms or suicidal behavior and ideation have been observed after discontinuation. Taper PREGABALIN extended-release tablets gradually over a minimum of 1 week. ( 5.4 )

Respiratory

Depression: May occur with pregabalin when used with concomitant CNS depressants or in the setting of underlying respiratory impairment. Monitor patients and adjust dosage as appropriate. ( 5.5 ) Dizziness and Somnolence: May cause dizziness and somnolence and impair patients ability to drive or operate machinery. ( 5.6 )

Peripheral

Edema : May cause peripheral edema. Monitor patients for the development of edema when co-administering pregabalin extended-release tablets and thiazolidinedione antidiabetic agents. ( 5.7 )

5.1 Angioedema There have been postmarketing reports of angioedema in patients during initial and chronic treatment with pregabalin. Specific symptoms included swelling of the face, mouth (tongue, lips, and gums), and neck (throat and larynx). There were reports of life-threatening angioedema with respiratory compromise requiring emergency treatment. Discontinue pregabalin extended-release tablets immediately in patients with these symptoms. Exercise caution when prescribing pregabalin extended-release tablets to patients who have had a previous episode of angioedema. In addition, patients who are taking other drugs associated with angioedema (e.g., angiotensin converting enzyme inhibitors [ACE-inhibitors]) may be at increased risk of developing angioedema.

5.2 Hypersensitivity Reactions There have been postmarketing reports of hypersensitivity reactions in patients shortly after initiation of treatment with pregabalin. Adverse reactions included skin redness, blisters, hives, rash, dyspnea, and wheezing. Discontinue pregabalin extended-release tablets immediately in patients with these symptoms.

5.3 Suicidal Behavior and Ideation Antiepileptic drugs (AEDs), including pregabalin, the active ingredient in pregabalin extended-release tablets, increase the risk of suicidal thoughts or behavior in patients taking these drugs for any indication. Suicidal behavior and ideation have also been reported in patients after discontinuation of pregabalin <span class="opacity-50 text-xs">[see Warnings and Precautions (5.4)]</span> . Monitor patients treated with any AED for any indication for the emergence or worsening of depression, suicidal thoughts or behavior, and/or any unusual changes in mood or behavior. Pooled analyses of 199 placebo-controlled clinical trials (mono- and adjunctive therapy) of 11 different AEDs showed that patients randomized to one of the AEDs had approximately twice the risk (adjusted Relative Risk 1.8, 95% CI:1.2, 2.7) of suicidal thinking or behavior compared to patients randomized to placebo. In these trials, which had a median treatment duration of 12 weeks, the estimated incidence rate of suicidal behavior or ideation among 27,863 AED-treated patients was 0.43%, compared to 0.24% among 16,029 placebo-treated patients, representing an increase of approximately one case of suicidal thinking or behavior for every 530 patients treated. There were four suicides in drug-treated patients in the trials and none in placebo-treated patients, but the number is too small to allow any conclusion about drug effect on suicide. The increased risk of suicidal thoughts or behavior with AEDs was observed as early as one week after starting drug treatment with AEDs and persisted for the duration of treatment assessed. Because most trials included in the analysis did not extend beyond 24 weeks, the risk of suicidal thoughts or behavior beyond 24 weeks could not be assessed. The risk of suicidal thoughts or behavior was generally consistent among drugs in the data analyzed. The finding of increased risk with AEDs of varying mechanisms of action and across a range of indications suggests that the risk applies to all AEDs used for any indication. The risk did not vary substantially by age (5-100years) in the clinical trials analyzed.

Table

3 shows absolute and relative risk by indication for all evaluated AEDs.

Table

3. Risk by Indication for Antiepileptic Drugs in the Pooled Analysis Indication Placebo Patients With Events per 1000 Patients Drug Patients With Events per 1000 Patients Relative Risk: Incidence of Events in Drug Patients/Incidence in Placebo Patients Risk Difference: Additional Drug Patients With Events per 1000 Patients Epilepsy 1.0 3.4 3.5

2.4 Psychiatric 5.7 8.5 1.5

2.9 Other 1.0 1.8 1.9

0.9 Total 2.4 4.3 1.8

1.9 The relative risk for suicidal thoughts or behavior was higher in clinical trials for epilepsy than in clinical trials for psychiatric or other conditions, but the absolute risk differences were similar for the epilepsy and psychiatric indications. Anyone considering prescribing pregabalin extended-release tablets must balance the risk of suicidal thoughts or behavior with the risk of untreated illness. Many other illnesses for which AEDs are prescribed are themselves associated with morbidity and mortality and an increased risk of suicidal thoughts and behavior. Should suicidal thoughts and behavior emerge during treatment, the prescriber needs to consider whether the emergence of these symptoms in any given patient may be related to the illness being treated. Inform patients, their caregivers, and families that pregabalin extended-release tablets can increase the risk of suicidal thoughts and behavior and advise them of the need to be alert for the emergence or worsening of the signs and symptoms of depression, any unusual changes in mood or behavior, or the emergence of suicidal thoughts, behavior, or thoughts about self-harm. Report behaviors of concern immediately to healthcare providers.

5.4 Increased Risk of Adverse Reactions with Abrupt or Rapid Discontinuation Following abrupt or rapid discontinuation of pregabalin extended-release tablets, some patients reported symptoms including, insomnia, nausea, headache, anxiety, and diarrhea <span class="opacity-50 text-xs">[see Adverse Reactions (6.2), Drug Abuse and Dependence (9.3)]</span> . Suicidal behavior and ideation have also been reported in patients after discontinuation of pregabalin <span class="opacity-50 text-xs">[see Warnings and Precautions (5.3)]</span> . Increased seizure frequency may occur in patients with seizure disorders taking pregabalin extended-release tablets for pain if pregabalin extended-release tablets is rapidly discontinued. Taper pregabalin extended-release tablets gradually over a minimum of 1 week rather than discontinuing the drug abruptly. The efficacy of pregabalin extended-release tablets as adjunctive therapy for adult patients with partial onset seizures has not been established.

5.5 Respiratory Depression There is evidence from case reports, human studies, and animal studies associating pregabalin with serious, life- threatening, or fatal respiratory depression when co-administered with central nervous system (CNS) depressants, including opioids, or in the setting of underlying respiratory impairment. When the decision is made to co-prescribe pregabalin extended-release tablets with another CNS depressant, particularly an opioid, or to prescribe pregabalin extended-release tablets to patients with underlying respiratory impairment, monitor patients for symptoms of respiratory depression and sedation, and consider initiating pregabalin extended-release tablets at a low dose. The management of respiratory depression may include close observation, supportive measures, and reduction or withdrawal of CNS depressants (including pregabalin extended-release tablets). There is more limited evidence from case reports, animal studies, and human studies associating pregabalin with serious respiratory depression, without co-administered CNS depressants or without underlying respiratory impairment.

5.6 Dizziness and Somnolence Pregabalin extended-release tablets may cause dizziness and somnolence. Inform patients that pregabalin extended-release tablets-related dizziness and somnolence may impair their ability to perform tasks such as driving or operating machinery. Concomitant use of pregabalin extended-release tablets with other central nervous system (CNS) depressants may exacerbate these effects <span class="opacity-50 text-xs">[see Drug Interactions (7) ]</span> . In the pregabalin extended-release tablets controlled trials for pain indications, dizziness was experienced by 24% of pregabalin extended-release tablets-treated patients during the single-blind phase; somnolence was experienced by 15.8% of pregabalin extended-release tablets-treated patients. Dizziness and somnolence generally began shortly after the initiation of pregabalin extended-release tablets therapy and occurred more frequently at higher doses. Dizziness and somnolence were the adverse reactions most frequently leading to withdrawal (2.4%, 1.2% each) during the single-blind phase of the controlled studies. In pregabalin-treated patients reporting these adverse reactions in short-term, controlled studies, dizziness persisted until the last dose in 30% and somnolence persisted until the last dose in 42% of patients.

5.7 Peripheral Edema Pregabalin extended-release tablets treatment may cause peripheral edema. In short-term trials of patients without clinically significant heart or peripheral vascular disease, there was no apparent association between peripheral edema and cardiovascular complications such as hypertension or congestive heart failure. Peripheral edema was not associated with laboratory changes suggestive of deterioration in renal or hepatic function. In controlled clinical trials for pain indications, the incidence of peripheral edema for patients receiving pregabalin extended-release tablets in the single-blind phase was 5.3% of patients. In controlled clinical trials for pain indications, 0.8% of pregabalin extended-release tablets patients withdrew due to peripheral edema during the single-blind phase. Higher frequencies of weight gain and peripheral edema were observed in patients taking both pregabalin and a thiazolidinedione antidiabetic agent compared to patients taking either drug alone. The majority of patients using thiazolidinedione antidiabetic agents in the overall safety database were participants in studies of pain associated with diabetic peripheral neuropathy. In this population, peripheral edema was reported in 3% (2/60) of patients who were using thiazolidinedione antidiabetic agents only, 8% (69/859) of patients who were treated with pregabalin only, and 19% (23/120) of patients who were on both pregabalin and thiazolidinedione antidiabetic agents. Similarly, weight gain was reported in 0% (0/60) of patients on thiazolidinediones only;4% (35/859) of patients on pregabalin only; and 7.5% (9/120) of patients on both drugs. As the thiazolidinedione class of antidiabetic drugs can cause weight gain and/or fluid retention, possibly exacerbating or leading to heart failure, monitor patients for the development of edema when co-administering pregabalin extended-release tablets and these agents. Because there are limited data on congestive heart failure patients with New York Heart Association (NYHA) Class III or IV cardiac status, monitor these patients for possible exacerbation of congestive heart failure symptoms when using pregabalin extended-release tablets.

5.8 Weight Gain Pregabalin extended-release tablets treatment may cause weight gain. In pregabalin extended-release tablets controlled trials for pain indications, weight gain was experienced by 4% of pregabalin extended-release tablets-treated patients during the single-blind phase. Adverse events of weight gain were observed in 3.7% of pregabalin extended-release tablets-treated patients and 1% of placebo-treated patients during the double-blind phase. In pregabalin controlled clinical trials of up to 14 weeks a gain of 7% or more over baseline weight was observed in 9% of pregabalin -treated patients and 2% of placebo-treated patients. Few patients treated with pregabalin (0.3%) withdrew from controlled trials due to weight gain. In studies with pregabalin, associated weight gain was related to pregabalin dose and duration of exposure, but did not appear to be associated with baseline BMI, gender, or age. Weight gain was not limited to patients with edema <span class="opacity-50 text-xs">[see Warnings and Precautions (5.7) ]</span> . Although weight gain was not associated with clinically important changes in blood pressure in short-term controlled studies with pregabalin, the long-term cardiovascular effects of pregabalin-associated weight gain are unknown. Among diabetic patients, pregabalin -treated patients gained an average of 1.6 kg (range: -16 to 16 kg), compared to an average 0.3 kg (range: -10 to 9 kg) weight gain in placebo patients. In a cohort of 333 diabetic patients who received pregabalin for at least 2 years, the average weight gain was 5.2 kg. While the effects of pregabalin-associated weight gain on glycemic control have not been systematically assessed, in controlled and longer-term open-label clinical trials with diabetic patients, pregabalin treatment did not appear to be associated with loss of glycemic control (as measured by HbA 1C ).

5.9 Tumorigenic Potential In standard preclinical in vivo lifetime carcinogenicity studies of pregabalin, an unexpectedly high incidence of hemangiosarcoma was identified in 2 different strains of mice <span class="opacity-50 text-xs">[see Nonclinical Toxicology (13.1) ]</span> . The clinical significance of this finding is unknown. Clinical experience during premarketing development of pregabalin provides no direct means to assess its potential for inducing tumors in humans. In clinical studies across various patient populations, comprising 6396 patient-years of exposure in patients greater than 12 years of age, new or worsening preexisting tumors were reported in 57 patients. Without knowledge of the background incidence and recurrence in similar populations not treated with pregabalin, it is impossible to know whether the incidence seen in these cohorts is or is not affected by treatment.

5.10 Ophthalmological Effects In controlled studies for pain indications, 4.8% of patients treated with pregabalin extended-release tablets in the single-blind phase reported blurred vision, which resolved in a majority of cases with continued dosing. Less than 1% of patients discontinued pregabalin extended-release tablets treatment due to vision-related events (primarily blurred vision). Additionally, 0.7% of pregabalin extended-release tablets-treated patients as compared to no placebo-treated patients experienced blurred vision in the double-blind phase. Prospectively planned ophthalmologic testing during the premarketing development of pregabalin, including visual acuity testing, formal visual field testing and dilated funduscopic examination, was performed in over 3600 patients. In these patients, visual acuity was reduced in 7% of pregabalin -treated patients and 5% of placebo-treated patients. Visual field changes were detected in 13% of pregabalin -treated and 12% of placebo-treated patients. Funduscopic changes were observed in 2% of pregabalin -treated and 2% of placebo-treated patients. Although the clinical significance of the ophthalmologic findings is unknown, inform patients to notify their physician if changes in vision occur. If visual disturbance persists, consider further assessment. Consider more frequent assessment for patients who are already routinely monitored for ocular conditions.

5.11 Creatine Kinase Elevations Pregabalin treatment was associated with creatine kinase elevations. Mean changes in creatine kinase from baseline to the maximum value were 60 U/L for pregabalin -treated patients and 28 U/L for the placebo patients. In all controlled trials across multiple patient populations, 1.5% of patients on pregabalin and 0.7% of placebo patients had a value of creatine kinase at least 3 times the upper limit of normal. Three pregabalin -treated subjects had events reported as rhabdomyolysis in premarketing clinical trials. The relationship between these myopathy events and pregabalin is not completely understood because the cases had documented factors that may have caused or contributed to these events. Instruct patients to promptly report unexplained muscle pain, tenderness, or weakness, particularly if these muscle symptoms are accompanied by malaise or fever. Discontinue treatment with pregabalin extended-release tablets if myopathy is diagnosed or suspected or if markedly elevated creatine kinase levels occur.

5.12 Decreased Platelet Count Both pregabalin extended-release tablets and pregabalin treatment were associated with a decrease in platelet count. In the double-blind phase of controlled studies for pain indication, pregabalin extended-release tablets-treated patients experienced a median change from baseline in platelet count of 11 × 10 3 /mm 3 (for the PHN population) and 14 × 10 3 /mm 3 (for the FM population) as compared to 1 × 10 3 /mm 3 in placebo-treated patients (for both populations). Pregabalin -treated patients experienced a mean maximal decrease in platelet count of 20 × 10 3 /µL, compared to 11 × 10 3 /µL in placebo patients. In the overall database of controlled trials, 2% of placebo patients and 3% of pregabalin patients experienced a potentially clinically significant decrease in platelets, defined as 20% below baseline value and less than 150 × 10 3 /µL. A single pregabalin -treated subject developed severe thrombocytopenia with a platelet count less than 20 × 10 3 /µL. In randomized controlled trials, pregabalin or pregabalin extended-release tablets were not associated with an increase in bleeding-related adverse reactions.

5.13 PR Interval Prolongation Pregabalin treatment was associated with PR interval prolongation. In analyses of clinical trial ECG data, the mean PR interval increase was 3–6 msec at pregabalin doses greater than or equal to 300 mg/day. This mean change difference was not associated with an increased risk of PR increase greater than or equal to 25% from baseline, an increased percentage of subjects with on-treatment PR greater than 200 msec, or an increased risk of adverse reactions of second or third degree AV block. Subgroup analyses did not identify an increased risk of PR prolongation in patients with baseline PR prolongation or in patients taking other PR prolonging medications. However, these analyses cannot be considered definitive because of the limited number of patients in these categories.

INTERACTIONS Since pregabalin is predominantly excreted unchanged in the urine, undergoes negligible metabolism in humans (less than 2% of a dose recovered in urine as metabolites), and does not bind to plasma proteins, its pharmacokinetics are unlikely to be affected by other agents through metabolic interactions or protein binding displacement. In vitro and in vivo studies showed that pregabalin is unlikely to be involved in significant pharmacokinetic drug interactions. Specifically, there are no pharmacokinetic interactions between pregabalin and the following antiepileptic drugs: carbamazepine, valproic acid, lamotrigine, phenytoin, phenobarbital, and topiramate. Important pharmacokinetic interactions would also not be expected to occur between pregabalin and commonly used antiepileptic drugs [see Clinical Pharmacology (12) ] .

Pharmacodynamics

Multiple oral doses of pregabalin were co-administered with oxycodone, lorazepam, or ethanol. Although no pharmacokinetic interactions were seen, additive effects on cognitive and gross motor functioning were seen when pregabalin was co-administered with these drugs. No clinically important effects on respiration were seen.

Drug Interactions In Vitro Studies

Pregabalin, at concentrations that were, in general, 10-times those attained in clinical trials, does not inhibit human CYP1A2, CYP2A6, CYP2C9, CYP2C19, CYP2D6, CYP2E1, and CYP3A4 enzyme systems. In vitro drug interaction studies demonstrate that pregabalin does not induce CYP1A2 or CYP3A4 activity. Therefore, an increase in the metabolism of coadministered CYP1A2 substrates (e.g., theophylline, caffeine) or CYP3A4 substrates (e.g., midazolam, testosterone) is not anticipated.

In Vivo Studies

The drug interaction studies described in this section were conducted in healthy adults, and across various patient populations.