Clobazam

Boxed Warning 2/2021 Dosage and Administration ( 2.2 ) 2/2021 Warnings and Precautions ( 5.2 , 5.3 ) 2/2021

1 INDICATIONS AND USAGE Clobazam oral suspension is indicated for the adjunctive treatment of seizures associated with Lennox-Gastaut syndrome (LGS) in patients 2 years of age or older. Clobazam oral suspension is a benzodiazepine indicated for adjunctive treatment of seizures associated with Lennox-Gastaut syndrome (LGS) in patients 2 years of age or older. ( 1 )

2 DOSAGE AND ADMINISTRATION For doses above 5 mg/day administer in two divided doses ( 2.1 ) Patients ≤30 kg body weight: Initiate at 5 mg daily and titrate as tolerated up to 20 mg daily ( 2.1 ) Patients greater than 30 kg body weight: Initiate at 10 mg daily and titrate as tolerated up to 40 mg daily ( 2.1 ) Dosage adjustment needed in following groups: o Geriatric patients ( 2.4 , 8.5 ) o Known CYP2C19 poor metabolizers ( 2.5 ) o Mild or moderate hepatic impairment; no information for severe hepatic impairment ( 2.7 , 8.8 ) Measure prescribed amount of oral suspension using provided adapter and dosing syringe ( 2.3 ) Oral suspension: Can be taken with or without food ( 2.3 ) 2.1 Dosing Information A daily dose of clobazam oral suspension greater than 5 mg should be administered in divided doses twice daily; a 5 mg daily dose can be administered as a single dose. Dose patients according to body weight. Individualize dosing within each body weight group, based on clinical efficacy and tolerability. Each dose in Table 1 (e.g., 5 to 20 mg in ≤30 kg weight group) has been shown to be effective, although effectiveness increases with increasing dose [see Clinical Studies ( 14 )]. Do not proceed with dose escalation more rapidly than weekly, because serum concentrations of clobazam and its active metabolite require 5 and 9 days, respectively, to reach steady-state. Table 1. Recommended Total Daily Dosing by Weight Group ≤30 kg Body Weight Greater than 30 kg Body Weight Starting Dose 5 mg 10 mg Starting Day 7 10 mg 20 mg Starting Day 14 20 mg 40 mg 2.2 Discontinuation or Dosage Reduction of Clobazam Oral Suspension To reduce the risk of withdrawal reactions, increased seizure frequency, and status epilepticus, use a gradual taper to discontinue clobazam oral suspension or reduce the dosage. Taper by decreasing the total daily dose by 5 to 10 mg/day on a weekly basis until discontinued. If a patient develops withdrawal reactions, consider pausing the taper or increasing the dosage to the previous tapered dosage level. Subsequently decrease the dosage more slowly [see Warnings and Precautions ( 5.3 ) and Drug Abuse and Dependence ( 9.3 )] . 2.3 Important Administration Instructions Instruct patients to read the “Instructions for Use” carefully for complete directions on how to properly dose and administer clobazam oral suspension. Clobazam oral suspension Oral Administration Clobazam oral suspension can be taken with or without food [see Clinical Pharmacology ( 12.3 )]. Shake clobazam oral suspension well before every administration. When administering the oral suspension, use only the oral dosing syringe provided with the product. Each carton includes two syringes, but only one syringe should be used for dosing. The second oral syringe is reserved as a replacement in case the first syringe is damaged or lost. Insert the provided adapter firmly into the neck of the bottle before first use and keep the adapter in place for the duration of the usage of the bottle. To withdraw the dose, insert the dosing syringe into the adapter and invert the bottle then slowly pull back the plunger to prescribed dose. After removing the syringe from the bottle adapter, slowly squirt clobazam oral suspension into the corner of the patient’s mouth. Replace the cap after each use. The cap fits over the adapter when the adapter is properly placed. See clobazam oral suspension “Instructions for Use” for complete instruction on how to properly dose and administer the clobazam oral suspension. 2.4 Dosage Adjustments in Geriatric Patients Plasma concentrations at any given dose are generally higher in the elderly: proceed slowly with dose escalation. The starting dose should be 5 mg/day for all elderly patients. Then titrate elderly patients according to weight, but to half the dose presented in Table 1, as tolerated. If necessary and based upon clinical response, an additional titration to the maximum dose (20 mg/day or 40 mg/day, depending on weight) may be …

3 DOSAGE FORMS AND STRENGTHS Clobazam oral suspension 2.5 mg/mL for oral administration. Each bottle contains 120 mL of white to off-white suspension. Oral Suspension: 2.5 mg/mL in 120 mL bottles (3)

4 CONTRAINDICATIONS Clobazam oral suspension 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 , 5.7) ] . History of hypersensitivity to the drug or its ingredients ( 4 )

6 ADVERSE REACTIONS 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 oral suspension dose included constipation, somnolence or sedation, pyrexia, lethargy, and drooling ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Ascend Laboratories, LLC at 1-877-272-7901 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. During its development for the adjunctive treatment of seizures associated with LGS, clobazam oral suspension 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 oral suspension 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 oral suspension 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 oral suspension-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 Placebo N=59 % Clobazam oral suspension Dose Level All Clobazam oral suspension N=179 % Low a N=58 % Medium b N=62 % H i gh c N = 5 9 % 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 greater …

7 DRUG INTERACTIONS 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 clobazam oral suspension ( 7.3 ) Strong or Moderate CYP2C19 Inhibitors: Dosage adjustment of clobazam oral suspension may be necessary ( 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 clobazam oral suspension 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 clobazam oral suspension 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 Clobazam Oral Suspension on Other Drugs Hormonal Contraceptives Clobazam oral suspension is a weak CYP3A4 inducer. As some hormonal contraceptives are metabolized by CYP3A4, their effectiveness may be diminished when given with clobazam oral suspension. Additional non- hormonal forms of contraception are recommended when using clobazam oral suspension [see Clinical Pharmacology ( 12.3 ), Patient Counseling Information ( 17 )]. Drugs Metabolized by CYP2D6 Clobazam oral suspension inhibits CYP2D6. Dose adjustment of drugs metabolized by CYP2D6 may be necessary [see Clinical Pharmacology ( 12.3 )]. 7.4 Effect of Other Drugs on Clobazam Oral Suspension Strong and moderate inhibitors of CYP2C19 Strong and 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 clobazam oral suspension 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 )].

8 USE IN SPECIFIC POPULATIONS Pregnancy: Based on animal data, may cause fetal harm ( 8.1 ) 8.1 Pregnancy Pregnancy Registry There is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to AEDs, such as clobazam, during pregnancy. Healthcare providers are encouraged to recommend that pregnant women taking clobazam 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. Clobazam should be used during pregnancy only if the potential benefit to the mother justifies the potential risk to the fetus. Advise a pregnant woman and women of childbearing age of the potential risk to a fetus. 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 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 clobazam during pregnancy or labor for signs of sedation, respiratory depression, hypotonia, and feeding problems. Monitor neonates exposed to clobazam 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. …

12.1 Mechanism of Action 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.

11 DESCRIPTION Table 4. Description Proprietary Name: None Established Name: Clobazam Oral Suspension Dosage Forms: Oral Suspension Route of Administration: Oral Established Pharmacologic Class of Drug: Benzodiazepine Chemical Name: 7-Chloro-1-methyl-5-phenyl-1H-1,5 benzodiazepine-2,4( 3H,5H )-dione Structural Formula: Clobazam is a white to almost white crystalline powder with a slightly bitter taste; is practically insoluble in water, sparingly soluble in ethanol and in methanol, freely soluble in dichloromethane and in acetone. The melting range of clobazam is from 182oC to 185oC. The molecular formula is C 16 H 13 O 2 N 2 Cl and the molecular weight is 300.7. Clobazam is available for oral administration as a white to off-white suspension containing clobazam at a concentration of 2.5 mg/mL. Inactive ingredients include artificial mixed berry flavor, citric acid monohydrate, disodium hydrogen phosphate dihydrate, magnesium aluminum silicate, maltitol solution, methylparaben, polysorbate 80, propylene glycol, propylparaben, purified water, simethicone emulsion, sucralose powder, and xanthan gum. Stucture

10 OVERDOSAGE Overdosage of benzodiazepines is characterized by central nervous system depression ranging from drowsiness to coma. In mild to moderate cases, symptoms can include drowsiness, confusion, dysarthria, lethargy, hypnotic state, diminished reflexes, ataxia, and hypotonia. Rarely, paradoxical or disinhibitory reactions (including agitation, irritability, impulsivity, violent behavior, confusion, restlessness, excitement, and talkativeness) may occur. In severe overdosage cases, patients may develop respiratory depression and coma. Overdosage of benzodiazepines in combination with other CNS depressants (including alcohol and opioids) may be fatal [see Warnings and Precautions ( 5.2 )] . Markedly abnormal (lowered or elevated) blood pressure, heart rate, or respiratory rate raise the concern that additional drugs and/or alcohol are involved in the overdosage. In managing benzodiazepine overdosage, employ general supportive measures, including intravenous fluids and airway maintenance. Flumazenil, a specific benzodiazepine receptor antagonist indicated for the complete or partial reversal of the sedative effects of benzodiazepines in the management of benzodiazepine overdosage, can lead to withdrawal and adverse reactions, including seizures, particularly in the context of mixed overdosage with drugs that increase seizure risk (e.g., tricyclic and tetracyclic antidepressants) and in patients with long-term benzodiazepine use and physical dependency. The risk of withdrawal seizures with flumazenil may be increased in patients with epilepsy. Flumazenil is contraindicated in patients who have received a benzodiazepine for control of a potentially life-threatening condition (e.g., status epilepticus). If the decision is made to use flumazenil, it should be used as an adjunct to, not as a substitute for, supportive management of benzodiazepine overdosage. See the flumazenil injection Prescribing Information. Consider contacting the Poison Help line (1-800-222-1222) or a medical toxicologist for additional overdosage management recommendations.

16 HOW SUPPLIED/STORAGE AND HANDLING Clobazam oral suspension is a strawberry flavored off-white liquid supplied in a bottle with child-resistant closure. The oral suspension is packaged with a dispenser set which contains two calibrated oral dosing syringes and a bottle adapter. Store and dispense clobazam oral suspension in its original bottle in an upright position. Use within 90 days of first opening the bottle, then discard any remainder. NDC 31722-641-12: 2.5 mg/mL supplied in a amber glass bottle containing 120 mL of suspension. Store oral suspension at 20°C to 25 o C (68°F to 77 o F) [see USP Controlled Room Temperature].