DIAZEPAM Drug Interactions: What You Need to Know

DRUG INTERACTIONS There have been no clinical studies or reports in literature to evaluate the interaction of rectally administered diazepam with other drugs. As with all drugs, the potential for interaction by a variety of mechanisms is a possibility. Effect of Concomitant Use of Benzodiazepines and Opioids: The concomitant use of benzodiazepines and opioids increases the risk of respiratory depression because of actions at different receptor sites in the CNS that control respiration. Benzodiazepines interact at GABA A sites, and opioids interact primarily at mu receptors. When benzodiazepines and opioids are combined, the potential for benzodiazepines to significantly worsen opioid-related respiratory depression exists. Limit dosage and duration of concomitant use of benzodiazepines and opioids, and follow patients closely for respiratory depression and sedation.

Other Psychotropic

Agents or Other CNS Depressants: If diazepam rectal gel is to be combined with other psychotropic agents or other CNS depressants, careful consideration should be given to the pharmacology of the agents to be employed particularly with known compounds which may potentiate the action of diazepam, such as phenothiazines, narcotics, barbiturates, MAO inhibitors and other antidepressants. Cimetidine: The clearance of diazepam and certain other benzodiazepines can be delayed in association with cimetidine administration. The clinical significance of this is unclear. Valproate: Valproate may potentiate the CNS-depressant effects of diazepam. Effect of Other Drugs on Diazepam Metabolism: In vitro studies using human liver preparations suggest that CYP2C19 and CYP3A4 are the principal isozymes involved in the initial oxidative metabolism of diazepam. Therefore, potential interactions may occur when diazepam is given concurrently with agents that affect CYP2C19 and CYP3A4 activity. Potential inhibitors of CYP2C19 (e.g., cimetidine, quinidine, and tranylcypromine) and CYP3A4 (e.g., ketoconazole, troleandomycin, and clotrimazole) could decrease the rate of diazepam elimination, while inducers of CYP2C19 (e.g., rifampin) and CYP3A4 (e.g., carbamazepine, phenytoin, dexamethasone and phenobarbital) could increase the rate of elimination of diazepam. Effect of Diazepam on the Metabolism of Other Drugs: There are no reports as to which isozymes could be inhibited or induced by diazepam. But, based on the fact that diazepam is a substrate for CYP2C19 and CYP3A4, it is possible that diazepam may interfere with the metabolism of drugs which are substrates for CYP2C19, (e.g. omeprazole, propranolol, and imipramine) and CYP3A4 (e.g. cyclosporine, paclitaxel, terfenadine, theophylline, and warfarin) leading to a potential drug-drug interaction. Carcinogenesis, Mutagenesis, Impairment of Fertility The carcinogenic potential of rectal diazepam has not been evaluated. In studies in which mice and rats were administered diazepam in the diet at a dose of 75 mg/kg/day (approximately six and 12 times, respectively, the maximum recommended human dose [MRHD=1 mg/kg/day] on a mg/m2 basis) for 80 and 104 weeks, respectively, an increased incidence of liver tumors was observed in males of both species. The data currently available are inadequate to determine the mutagenic potential of diazepam. Reproduction studies in rats showed decreases in the number of pregnancies and in the number of surviving offspring following administration of an oral dose of 100 mg/kg/day (approximately 16 times the MRHD on a mg/m2 basis) prior to and during mating and throughout gestation and lactation. No adverse effects on fertility or offspring viability were noted at a dose of 80 mg/kg/day (approximately 13 times the MRHD on a mg/m2 basis).

Pregnancy Risk Summary

Neonates born to mothers using benzodiazepines late in pregnancy have been reported to experience symptoms of sedation and/or neonatal withdrawal (see WARNINGS: Neonatal Sedation and Withdrawal Syndrome and PRECAUTIONS: Pregnancy, Clinical Considerations ). Available data from published observational studies of pregnant women exposed to benzodiazepines do not report a clear association with benzodiazepines and major birth defects (see Human Data ). In animal studies, administration of diazepam during the organogenesis period of pregnancy resulted in increased incidences of fetal malformations at doses greater than those used clinically. Data for diazepam and other benzodiazepines suggest the possibility of increased neuronal cell death and long-term effects on neurobehavioral and immunological function based on findings in animals following prenatal or early postnatal exposure at clinically relevant doses (see Animal Data ). The 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 risk of major birth defects and of miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively.

Clinical Considerations Fetal/Neonatal

Adverse Reactions Benzodiazepines cross the placenta and may produce respiratory depression, hypotonia, and sedation in neonates. Monitor neonates exposed to diazepam rectal gel during pregnancy or labor for signs of sedation, respiratory depression, hypotonia, and feeding problems. Monitor neonates exposed to diazepam rectal gel during pregnancy for signs of withdrawal. Manage these neonates accordingly (see WARNINGS: Neonatal Sedation and Withdrawal Syndrome ).

Data Human Data

Published data from observational studies on the use of benzodiazepines during pregnancy do not report a clear association with benzodiazepines and major birth defects. Although early studies reported an increased risk of congenital malformations with diazepam and chlordiazepoxide, there was no consistent pattern noted. In addition, the majority of more recent case-control and cohort studies of benzodiazepine use during pregnancy, which were adjusted for confounding exposures to alcohol, tobacco and other medications, have not confirmed these findings.

Animal Data

Diazepam has been shown to produce increased incidences of fetal malformations in mice and hamsters when given orally at single doses of 100 mg/kg or greater (approximately 20 times the maximum recommended adult human dose [0.4 mg/kg/day] or greater on a mg/m2 basis). Cleft palate and exencephaly are the most common and consistently reported malformations produced in these species by administration of high, maternally-toxic doses of diazepam during organogenesis. In published animal studies, administration of benzodiazepines or other drugs that enhance GABAergic neurotransmission to neonatal rats has been reported to result in widespread apoptotic neurodegeneration in the developing brain at plasma concentrations relevant for seizure control in humans. The window of vulnerability to these changes in rats (postnatal days 0-14) includes a period of brain development that takes place during the third trimester of pregnancy in humans.

Nursing Mothers Risk Summary

Diazepam is present in breastmilk. There are reports of sedation, poor feeding and poor weight gain in infants exposed to benzodiazepines through breast milk. There are no data on the effects of diazepam on milk production. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for diazepam rectal gel and any potential adverse effects on the breastfed infant from diazepam rectal gel or from the underlying maternal condition.

Clinical Considerations

Infants exposed to diazepam rectal gel through breast milk should be monitored for sedation, poor feeding and poor weight gain. Because diazepam and its metabolites may be present in human breast milk for prolonged periods of time after acute use of diazepam rectal gel, patients should be advised not to breastfeed for an appropriate period of time after receiving treatment with diazepam rectal gel. Caution in Renally Impaired Patients Metabolites of diazepam rectal gel are excreted by the kidneys; to avoid their excess accumulation, caution should be exercised in the administration of the drug to patients with impaired renal function. Caution in Hepatically Impaired Patients Concomitant liver disease is known to decrease the clearance of diazepam (see CLINICAL PHARMACOLOGY: Special Populations, Hepatic Impairment ). Therefore, diazepam rectal gel should be used with caution in patients with liver disease. Use in Pediatrics The controlled trials demonstrating the effectiveness of diazepam rectal gel included children two years of age and older. Clinical studies have not been conducted to establish the efficacy and safety of diazepam rectal gel in children under two years of age. Use in Patients with Compromised Respiratory Function Diazepam rectal gel should be used with caution in patients with compromised respiratory function related to a concurrent disease process (e.g., asthma, pneumonia) or neurologic damage. Use in Elderly In elderly patients diazepam rectal gel should be used with caution due to an increase in half-life with a corresponding decrease in the clearance of free diazepam. It is also recommended that the dosage be decreased to reduce the likelihood of ataxia or oversedation.

CONTRAINDICATIONS Diazepam tablets are contraindicated in patients with a known hypersensitivity to diazepam and, because of lack of sufficient clinical experience, in pediatric patients under 6 months of age. Diazepam tablets are also contraindicated in patients with myasthenia gravis, severe respiratory insufficiency, severe hepatic insufficiency, and sleep apnea syndrome. They may be used in patients with open-angle glaucoma who are receiving appropriate therapy, but are contraindicated in acute narrow-angle glaucoma.

AND PRECAUTIONS CNS Depression: Monitor for central nervous system (CNS) depression. May cause an increased CNS-depressant effect when used with alcohol or other CNS depressants. ( 5.4 , 7.2 )

Suicidal

Behavior and Ideation: Monitor patients for suicidal ideation and behavior. ( 5.5 ) Glaucoma: VALTOCO can increase intraocular pressure in patients with glaucoma. VALTOCO may be used in patients with open-angle glaucoma only if they are receiving appropriate therapy. ( 4 , 5.6 )

Neonatal

Sedation and Withdrawal Syndrome: VALTOCO use during pregnancy can result in neonatal sedation and/or neonatal withdrawal. ( 5.7 , 8.1 )

5.1 Risk of Concomitant Use with Opioids Concomitant use of benzodiazepines, including VALTOCO, and opioids may result in profound sedation, respiratory depression, coma, and death <span class="opacity-50 text-xs">[see Drug Interactions (7.1) ]</span>. Because of these risks, reserve concomitant prescribing of benzodiazepines and opioids for 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 opioids alone. If a decision is made to prescribe VALTOCO concomitantly with opioids, prescribe the lowest effective dosages and minimum durations of concomitant use, and follow patients closely for signs and symptoms of respiratory depression and sedation. Advise both patients and caregivers about the risks of respiratory depression and sedation when VALTOCO is used with opioids.

5.2 Abuse, Misuse, and Addiction The use of benzodiazepines, including VALTOCO, exposes users to the risks of abuse, misuse, and addiction, which can lead to overdose or death. Abuse and misuse of benzodiazepines often (but not always) involve the use of doses greater than the maximum recommended dosage and commonly involve concomitant use of other medications, alcohol, and/or illicit substances, which is associated with an increased frequency of serious adverse outcomes, including respiratory depression, overdose, or death <span class="opacity-50 text-xs">[see Drug Abuse and Dependence (9.2) ]</span> . Before prescribing VALTOCO and throughout treatment, assess each patient&apos;s risk for abuse, misuse, and addiction. Use of VALTOCO, particularly in patients at elevated risk, necessitates counseling about the risks and proper use of VALTOCO along with monitoring for signs and symptoms of abuse, misuse, and addiction. Do not exceed the recommended dosing frequency; avoid or minimize concomitant use of CNS depressants and other substances associated with abuse, misuse, and addiction (e.g., opioid analgesics, stimulants); and advise patients on the proper disposal of unused drug. If a substance use disorder is suspected, evaluate the patient and institute (or refer them for) early treatment, as appropriate.

5.3 Dependence and Withdrawal Reactions After Use of VALTOCO More Frequently Than Recommended For patients using VALTOCO more frequently than recommended, to reduce the risk of withdrawal reactions, use a gradual taper to discontinue VALTOCO (a patient-specific plan should be used to taper the dose). Patients at an increased risk of withdrawal adverse reactions after benzodiazepine discontinuation or rapid dosage reduction include those who take higher dosages, and those who have had longer durations of use.

Acute Withdrawal Reactions

The continued use of benzodiazepines may lead to clinically significant physical dependence. Although VALTOCO is indicated only for intermittent use [see Indications and Usage (1) and Dosage and Administration (2) ] , if used more frequently than recommended, abrupt discontinuation or rapid dosage reduction of VALTOCO, or administration of flumazenil (a benzodiazepine antagonist) may precipitate acute withdrawal reactions, which can be life-threatening (e.g., seizures) [see Drug Abuse and Dependence (9.3) ].

Protracted Withdrawal

Syndrome In some cases, benzodiazepine users have developed a protracted withdrawal syndrome with withdrawal symptoms lasting weeks to more than 12 months [see Drug Abuse and Dependence (9.3) ] .

5.4 CNS Depression Benzodiazepines, including VALTOCO, produce CNS depression. Caution patients against engaging in hazardous activities requiring mental alertness (e.g., operating machinery, driving a motor vehicle, or riding a bicycle) until the effects of the drug, such as drowsiness, have subsided, and as their medical condition permits. Although VALTOCO is indicated for use solely on an intermittent basis, the potential for synergistic CNS-depressant effects when used simultaneously with alcohol or other CNS depressants must be considered by the prescriber and appropriate recommendations made to the patient and/or caregiver.

5.5 Suicidal Behavior and Ideation Antiepileptic drugs (AEDs), including VALTOCO, increase the risk of suicidal thoughts or behavior in patients taking these drugs for any indication. Patients treated with any AED for any indication should be monitored 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 (5-100 years) 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/1000 Patients Drug Patients with Events per 1000 Patients Relative Risk: Incidence of Drug 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 VALTOCO or any other AED must balance the risk of suicidal thoughts or behaviors with the risk of untreated illness. Epilepsy and 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.

5.6 Glaucoma Benzodiazepines, including VALTOCO, can increase intraocular pressure in patients with glaucoma. VALTOCO may be used in patients with open-angle glaucoma only if they are receiving appropriate therapy. VALTOCO is contraindicated in patients with narrow-angle glaucoma.

5.7 Neonatal Sedation and Withdrawal Syndrome Use of VALTOCO late in pregnancy can result in sedation (respiratory depression, lethargy, hypotonia) and/or withdrawal symptoms (hyperreflexia, irritability, restlessness, tremors, inconsolable crying, and feeding difficulties) in the neonate <span class="opacity-50 text-xs">[see Use in Specific Populations (8.1) ]</span> . Monitor neonates exposed to VALTOCO during pregnancy or labor for signs of sedation and monitor neonates exposed to VALTOCO during pregnancy for signs of withdrawal; manage these neonates accordingly.

5.8 Risk of Serious Adverse Reactions in Infants due to Benzyl Alcohol Preservative VALTOCO is not approved for use in neonates or infants. Serious and fatal adverse reactions including &quot;gasping syndrome&quot; can occur in neonates and low birth weight infants treated with benzyl alcohol-preserved drugs, including VALTOCO. The &quot;gasping syndrome&quot; is characterized by central nervous system depression, metabolic acidosis, and gasping respirations. The minimum amount of benzyl alcohol at which serious adverse reactions may occur is not known (VALTOCO contains 10.5 mg of benzyl alcohol per 0.1 mL) <span class="opacity-50 text-xs">[see Use in Specific Populations (8.4) ]</span>.