Clobazam

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.

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 started on day 21 [see Use in Specific Populations ( 8.5 )]. 2.5 Dosage Adjustments in CYP2C19 Poor Metabolizers In CYP2C19 poor metabolizers, levels of N-desmethylclobazam, clobazam’s active metabolite, will be increased. Therefore, in patients known to be CYP2C19 poor metabolizers, the starting dose should be 5 mg/day and dose titration should proceed slowly 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 the weight group) may be started on day 21 [see Use in Specific Populations ( 8.6 ), Clinical Pharmacology ( 12.5 )]. 2.6 Patients with Renal Impairment No dose adjustment is required for patients with mild and moderate renal impairment. There is no experience with clobazam oral suspension in patients with severe renal impairment or end stage renal disease (ESRD). It is not known if clobazam or its active metabolite, N-desmeth

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 than 30 kg body weight b Maximum daily dose of 10 mg for ≤30 kg body weight; 20 mg for greater than 30 kg body weight c Maximum daily dose of 20 mg for ≤30 kg body weight; 40 mg for greater than 30 kg body weight 6.2 Postmarketing Experience 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 depres

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 )].