Clobazam

SYMPAZAN ® is indicated for the adjunctive treatment of seizures associated with Lennox-Gastaut Syndrome (LGS) in patients 2 years of age or older. SYMPAZAN ® is a benzodiazepine indicated for adjunctive treatment of seizures associated with Lennox-Gastaut Syndrome (LGS) in patients 2 years of age or older ( 1 ).

SYMPAZAN ® Oral Film: Thin, white, rectangular, orally dissolving film strips: 5 mg imprinted with C5 10 mg imprinted with C10 20 mg imprinted with C20 Oral Film: 5 mg, 10 mg and 20 mg ( 3 )

SYMPAZAN ® is contraindicated in patients with a history of hypersensitivity to the drug or its ingredients. Hypersensitivity reactions have included serious dermatological reactions [see Warnings and Precautions (5.6) ]. History of hypersensitivity to the drug or its ingredients ( 4 )

Somnolence or Sedation: Monitor for central nervous system (CNS) depression. Risk may be increased with concomitant use of other CNS depressants ( 5.4 , 5.5 ) Serious Dermatological Reactions (including Stevens-Johnson Syndrome and toxic epidermal necrolysis): Discontinue SYMPAZAN ® at first sign of rash unless the rash is clearly not drug-related ( 5.6 ) Drug Reaction with Eosinophilia and Systemic Symptoms (Dress)/Multiorgan Hypersensitivity: Discontinue if no alternative etiology ( 5.7 ) Suicidal Behavior and Ideation: Monitor for suicidal thoughts or behaviors ( 5.8 ) Neonatal Sedation and Withdrawal Syndrome: SYMPAZAN use during pregnancy can result in neonatal sedation and/or neonatal withdrawal ( 5.9 , 8.1 )

5.1 Risks from Concomitant Use with Opioids Concomitant use of benzodiazepines, including SYMPAZAN ® , and opioids may result in profound sedation, respiratory depression, coma, and death. Because of these risks, reserve concomitant prescribing of benzodiazepines and opioids 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 opioids alone. If a decision is made to prescribe SYMPAZAN ® 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 SYMPAZAN ® is used with opioids [see Drug Interactions (7.1) ].

5.2 Abuse, Misuse, and Addiction The use of benzodiazepines, including SYMPAZAN, 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 [see Drug Abuse and Dependence (9.2) ]. Before prescribing SYMPAZAN and throughout treatment, assess each patient’s risk for abuse, misuse, and addiction (e.g., using a standardized screening tool). Use of SYMPAZAN, particularly in patients at elevated risk, necessitates counseling about the risks and proper use of SYMPAZAN along with monitoring for signs and symptoms of abuse, misuse, and addiction. Prescribe the lowest effective dosage; 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 To reduce the risk of withdrawal reactions, use a gradual taper to discontinue SYMPAZAN or reduce the dosage [see Dosage and Administration (2.2) ]. 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, including SYMPAZAN, may lead to clinically significant physical dependence. Abrupt discontinuation or rapid dosage reduction of SYMPAZAN after continued use, 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 Potentiation of Sedation from Concomitant Use with Central Nervous System Depressants Since SYMPAZAN ® has a central nervous system (CNS) depressant effect, patients or their caregivers should be cautioned against simultaneous use with other CNS depressant drugs or alcohol, and cautioned that the effects of other CNS depressant drugs or alcohol may be potentiated [see Drug Interactions (7.2) ].

5.5 Somnolence or Sedation SYMPAZAN ® causes somnolence and sedation. In clinical trials, somnolence or sedation was reported at all effective doses and was dose-related [see Adverse Reactions (6.1) ]. In general, somnolence and sedation begin within the first month of treatment and may diminish with continued treatment. Prescribers should monitor patients for somnolence and sedation, particularly with concomitant use of other central nervous system depressants. Prescribers should caution patients against engaging in hazardous activities requiring mental alertness, such as operating dangerous machinery or motor vehicles, until the effect of SYMPAZAN ® is known.

5.6 Serious Dermatological Reactions Serious skin reactions, including Stevens-Johnson Syndrome (SJS) and toxic epidermal necrolysis (TEN), have been reported with clobazam in both children and adults during the post-marketing period. Patients should be closely monitored for signs or symptoms of SJS/TEN, especially during the first 8 weeks of treatment initiation or when re-introducing therapy. SYMPAZAN ® should be discontinued at the first sign of rash, unless the rash is clearly not drug-related. If signs or symptoms suggest SJS/TEN, use of this drug should not be resumed and alternative therapy should be considered [see Contraindications (4) ].

5.7 Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS)/Multiorgan Hypersensitivity Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS), also known as multiorgan hypersensitivity, has been reported in patients taking antiepileptic drugs, including clobazam. These events can be fatal or life-threatening, particularly if diagnosis and treatment do not occur as early as possible. DRESS typically, although not exclusively, presents with fever, rash, lymphadenopathy, and/or facial swelling, in association with other organ system involvement, such as hepatitis, nephritis, hematological abnormalities, myocarditis, or myositis, sometimes resembling an acute viral infection. Eosinophilia is often present. Because this disorder is variable in its expression, other organ systems not noted here may be involved. It is important to note that early manifestations of hypersensitivity, such as fever or lymphadenopathy, may be present even though rash is not evident. If such signs or symptoms are present, the patient should be evaluated immediately. SYMPAZAN should be discontinued if an alternative etiology for the signs or symptoms cannot be established [see Contraindications ( 4 )] .

5.8 Suicidal Behavior and Ideation Antiepileptic drugs (AEDs), including SYMPAZAN ® , 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% confidence interval [CI]: 1.2, 2.7) of suicidal thinking or behavior compared to patients randomized to placebo. […]

Clinically significant adverse reactions that appear in other sections of the labeling include the following: Risks from Concomitant Use with Opioids [see Warnings and Precautions (5.1) ] Abuse, Misuse, and Addiction [see Warnings and Precautions (5.2) ] Dependence and Withdrawal Reactions [see Warnings and Precautions (5.3) ] Potentiation of Sedation from Concomitant Use with Central Nervous System Depressants [see Warnings and Precautions (5.4) ] Somnolence or Sedation [see Warnings and Precautions (5.5) ] Serious Dermatological Reactions [see Contraindications (4) , Warnings and Precautions (5.6) ] Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS)/Multiorgan Hypersensitivity [see Warnings and Precautions (5.7) ] Suicidal Behavior and Ideation [see Warnings and Precautions (5.8) ] Neonatal Sedation and Withdrawal Syndrome [see Warnings and Precautions (5.9) ] Adverse reactions that occurred at least 10% more frequently than placebo in any clobazam dose included constipation, somnolence or sedation, pyrexia, lethargy, and drooling ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact 1-800-518-1084 or FDA at 1-800-FDA-1088 or www.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. The following adverse events have been reported in clinical trials of patients treated with clobazam, the active ingredient of SYMPAZAN ® . During its development for the adjunctive treatment of seizures associated with LGS, clobazam was administered to 333 healthy volunteers and 300 patients with a current or prior diagnosis of LGS, including 197 patients treated for 12 months or more. The conditions and duration of exposure varied greatly and included single- and multiple-dose clinical pharmacology studies in healthy volunteers and two double-blind studies in patients with LGS (Study 1 and 2) [see Clinical Studies (14) ]. Only Study 1 included a placebo group, allowing comparison of adverse reaction rates on clobazam at several doses to placebo. Adverse Reactions Leading to Discontinuation in an LGS Placebo Controlled Clinical Trial (Study 1) The adverse reactions associated with clobazam treatment discontinuation in ≥1% of patients in decreasing order of frequency included lethargy, somnolence, ataxia, aggression, fatigue, and insomnia. Most Common Adverse Reactions in an LGS Placebo Controlled Clinical Trial (Study 1) Table 3 lists the adverse reactions that occurred in ≥5% of clobazam-treated patients (at any dose), and at a rate greater than placebo-treated patients, in the randomized, double-blind, placebo-controlled, parallel group clinical study of adjunctive AED therapy for 15 weeks (Study 1). Table 3: Adverse Reactions Reported for ≥5% of Patients and More Frequently than Placebo in Any Treatment Group Clobazam Dose Level All Clobazam N=179 % Placebo N=59 % Low a N=58 % Medium b N=62 % High c N=59 % Gastrointestinal Disorders Vomiting 5 9 5 7 7 Constipation 0 2 2 10 5 Dysphagia 0 0 0 5 2 General Disorders and Administration Site Conditions Pyrexia 3 17 10 12 13 Irritability 5 3 11 5 7 Fatigue 2 5 5 3 5 Infections and Infestations Upper respiratory tract infection 10 10 13 14 12 Pneumonia 2 3 3 7 4 Urinary tract infection 0 2 5 5 4 Bronchitis 0 2 0 5 2 Metabolism and Nutrition Disorders Decreased appetite 3 3 0 7 3 Increased appetite 0 2 3 5 3 Nervous System Disorders Somnolence or Sedation 15 17 27 32 26 Somnolence 12 16 24 25 22 Sedation 3 2 3 9 5 Lethargy 5 10 5 15 10 Drooling 3 0 13 14 9 Ataxia 3 3 2 10 5 Psychomotor hyperactivity 3 3 3 5 4 Dysarthria 0 2 2 5 3 Psychiatric Disorders Aggression 5 3 8 14 8 Insomnia 2 2 5 7 5 Respiratory Disorders Cough 0 3 5 7 5 a Maximum daily dose of 5 mg for ≤30 kg body weight; 10 mg for >30 kg body weight b Maximum daily dose of 10 mg for ≤30 kg body weight; 20 mg for >30 kg body weight c Maximum daily dose of 20 mg for ≤30 kg body weight; 40 mg for >30 kg body weight

6.2 Postmarketing Experience The following adverse reactions have been identified during post-approval use of clobazam tablets. These reactions are reported voluntarily from a population of uncertain size; therefore, it is not possible to estimate their frequency or establish a causal relationship to drug exposure. Adverse reactions are categorized by system organ class. Blood Disorders: Anemia, eosinophilia, leukopenia, thrombocytopenia Eye Disorders: Diplopia, vision blurred Gastrointestinal Disorders: Abdominal distention General Disorders and Administration Site Conditions: Hypothermia Investigations: Hepatic enzyme increased Musculoskeletal: Muscle spasms Psychiatric Disorders: Agitation, anxiety, apathy, confusional state, depression, delirium, delusion, hallucination Renal and Urinary Disorders: Urinary retention Respiratory Disorders: Aspiration, respiratory depression Skin and Subcutaneous Tissue Disorders: Rash, urticaria, angioedema, and facial and lip edema

Alcohol: Increases blood levels of clobazam by about 50% ( 7.2 ) Drugs metabolized by CYP2D6: Lower doses of these drugs may be required when used concomitantly with SYMPAZAN ® ( 7.3 ) Strong or Moderate CYP2C19 Inhibitors: Dosage adjustment of SYMPAZAN ® may be necessary ( 7.4 ) Cannabidiol: May increase risk of SYMPAZAN-related adverse reactions; consider dosage adjustment if this occurs ( 7.4 )

7.1 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 [see Warnings and Precautions (5.1) ]. 7.2 CNS Depressants and Alcohol Concomitant use of SYMPAZAN ® with other CNS depressants may increase the risk of sedation and somnolence [see Warnings and Precautions (5.4) ]. Alcohol, as a CNS depressant, will interact with SYMPAZAN ® in a similar way and also increases clobazam's maximum plasma exposure by approximately 50%. Therefore, caution patients or their caregivers against simultaneous use with other CNS depressant drugs or alcohol, and caution that the effects of other CNS depressant drugs or alcohol may be potentiated [see Warnings and Precautions (5.4) ].

7.3 Effect of SYMPAZAN ® on Other Drugs Hormonal Contraceptives SYMPAZAN ® is a weak CYP3A4 inducer. As some hormonal contraceptives are metabolized by CYP3A4, their effectiveness may be diminished when given with SYMPAZAN ® . Additional non-hormonal forms of contraception are recommended when using SYMPAZAN ® [see Clinical Pharmacology (12.3) , Patient Counseling Information (17) ]. Drugs Metabolized by CYP2D6 SYMPAZAN ® inhibits CYP2D6. Dose adjustment of drugs metabolized by CYP2D6 may be necessary [see Clinical Pharmacology (12.3) ].

7.4 Effect of Other Drugs on SYMPAZAN ® Strong and Moderate Inhibitors of CYP2C19 Coadministration with strong or moderate inhibitors of CYP2C19 may result in increased exposure to N-desmethylclobazam, the active metabolite of clobazam. This may increase the risk of dose-related adverse reactions. Dosage adjustment of SYMPAZAN ® may be necessary when co-administered with strong CYP2C19 inhibitors (e.g., fluconazole, fluvoxamine, ticlopidine) or moderate CYP2C19 inhibitors (e.g., omeprazole) [see Clinical Pharmacology (12.3) ]. Effect of Cannabidiol on SYMPAZAN ® Coadministration of cannabidiol, a CYP3A4 and CYP2C19 substrate and a CYP2C19 inhibitor, with clobazam may increase the risk of clobazam-related adverse reactions [ see Warnings and Precautions (5.4, 5.5) , Clinical Pharmacology (12.3) ]. Consider a reduction in dosage of cannabidiol or clobazam if adverse reactions known to occur with SYMPAZAN are experienced.

Pregnancy: Based on animal data, may cause fetal harm ( 8.1 )

8.1 Pregnancy Pregnancy Exposure Registry There is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to AEDs, such as SYMPAZAN ® , during pregnancy. Healthcare providers are encouraged to recommend that pregnant women taking SYMPAZAN ® enroll in the North American Antiepileptic Drug (NAAED) Pregnancy Registry by calling 1-888-233-2334 or online at http://www.aedpregnancyregistry.org/ 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 and Precautions (5.9) and 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 Data ). Administration of clobazam to pregnant rats and rabbits during the period of organogenesis or to rats throughout pregnancy and lactation resulted in developmental toxicity, including increased incidences of fetal malformations and mortality, at plasma exposures for clobazam and its major active metabolite, N-desmethylclobazam, below those expected at therapeutic doses in patients [ see Animal Data ]. Data for other benzodiazepines suggest the possibility of long-term effects on neurobehavioral and immunological function in animals following prenatal exposure to benzodiazepines at clinically relevant doses. 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 background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2%-4% and 15% -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 SYMPAZAN during pregnancy or labor for signs of sedation, respiratory depression, hypotonia, and feeding problems. Monitor neonates exposed to SYMPAZAN during pregnancy for signs of withdrawal. Manage these neonates accordingly [see Warnings and Precautions (5.9) ]. 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 In a study in which clobazam (0, 150, 450, or 750 mg/kg/day) was orally administered to pregnant rats throughout the period of organogenesis, embryofetal mortality and incidences of fetal skeletal variations were increased at all doses. The low-effect dose for embryofetal developmental toxicity in rats (150 mg/kg/day) was associated with plasma exposures (AUC) for clobazam and its major active metabolite, N-desmethylclobazam, lower than those in humans at the maximum recommended human dose (MRHD) of 40 mg/day. Oral administration of clobazam (0, 10, 30, or 75 mg/kg/day) to pregnant rabbits throughout the period of organogenesis resulted in decreased fetal body weights, and increased incidences of fetal malformations (visceral and skeletal) at the mid and high doses, and an increase in embryofetal mortality at the high dose. Incidences of fetal variations were increased at all doses. The highest dose tested was associated with maternal toxicity (ataxia and decreased activity). The low effect dose for embryofetal developmental toxicity in rabbits (10 mg/kg/day) was associated with plasma exposures for clobazam and N-desmethylclobazam lower than those in humans at the MRHD. Oral administration of clobazam (0, 50, 350, or 750 mg/kg/day) to rats throughout pregnancy and lactation resulted in increased embryofetal mortality at the high dose, decreased pup survival at the mid and high doses and alterations in offspring behavior (locomotor activity) at all doses. The low-effect dose for adverse effects on preand postnatal development in rats (50 mg/kg/day) was associated with plasma exposures for clobazam and N-desmethylclobazam lower than those in humans at the MRHD.

8.2 Lactation Risk Summary SYMPAZAN ® is excreted in human milk (see Data). 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 clobazam on milk production. The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for SYMPAZAN ® and any potential adverse effects on the breastfed infant from SYMPAZAN ® or from the underlying maternal condition. Clinical Considerations Adverse reactions such as somnolence and difficulty feeding have been reported in infants during breastfeeding in postmarketing experience with clobazam. Infants exposed to SYMPAZAN through breast milk should be monitored for sedation, poor feeding and poor weight gain. Data Scientific literature on clobazam use during lactation is limited. After short-term administration, clobazam and N-desmethylclobazam are transferred into breast milk.

8.3 Females and Males of Reproductive Potential Administration of clobazam to rats prior to and during mating and early gestation resulted in adverse effects on fertility and early embryonic development at plasma exposures for clobazam and its major active metabolite, N-desmethylclobazam, below those in humans at the MRHD [see Nonclinical Toxicology (13.1) ].

8.4 Pediatric Use Safety and effectiveness for the adjunctive treatment of seizures associated with Lennox-Gastaut syndrome in pediatric patients 2 years of age and older have been established in two adequate and well-controlled studies [see Clinical Studies (14) ]. Safety and effectiveness in patients less than 2 years of age have not been established. Juvenile Animal Data In a study in which clobazam (0, 4, 36, or 120 mg/kg/day) was orally administered to rats during the juvenile period of development (postnatal days 14 to 48), adverse effects on growth (decreased bone density and bone length) and behavior (altered motor activity and auditory startle response; learning deficit) were observed at the high dose. The effect on bone density, but not on behavior, was reversible when drug was discontinued. The no-effect level for juvenile toxicity (36 mg/kg/day) was associated with plasma exposures (AUC) to clobazam and its major active metabolite, N-desmethylclobazam, less than those expected at therapeutic doses in pediatric patients.

8.5 Geriatric Use Clinical studies of clobazam did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. However, elderly subjects appear to eliminate clobazam more slowly than younger subjects based on population pharmacokinetic analysis. For these reasons, dosage modification is recommended [see Dosage and Administration (2.4) , Clinical Pharmacology (12.3) ]. 8.6 CYP2C19 Poor Metabolizers Concentrations of clobazam's active metabolite, N-desmethylclobazam, are higher in CYP2C19 poor metabolizers than in extensive metabolizers. For this reason, dosage modification is recommended [see Dosage and Administration (2.5) , Clinical Pharmacology (12.3) ].

8.7 Renal Impairment The pharmacokinetics of clobazam were evaluated in patients with mild and moderate renal impairment. […]

The exact mechanism of action for clobazam, a 1,5-benzodiazepine, is not fully understood but is thought to involve potentiation of GABAergic neurotransmission resulting from binding at the benzodiazepine site of the GABA A receptor.