clobazam

Clobazam tablets are indicated for the adjunctive treatment of seizures associated with Lennox-Gastaut syndrome (LGS) in patients 2 years of age or older. Clobazam tablets are a benzodiazepine indicated for adjunctive treatment of seizures associated with Lennox-Gastaut syndrome (LGS) in patients 2 years of age or older

For doses above 5 mg/day administer in two divided doses Patients ≤30 kg body weight: Initiate at 5 mg daily and titrate as tolerated up to 20 mg daily Patients >30 kg body weight: Initiate at 10 mg daily and titrate as tolerated up to 40 mg daily Dosage adjustment needed in following groups: Geriatric patients Known CYP2C19 poor metabolizers Mild or moderate hepatic impairment; no information for severe hepatic impairment Administer whole, broken in half along the score, or crush and mix in applesauce Tablets can be taken with or without food 2.1 Dosing Information A daily dose of clobazam tablets 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 ]. 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 >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 To reduce the risk of withdrawal reactions, increased seizure frequency, and status epilepticus, use a gradual taper to discontinue clobazam 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 and Drug Abuse and Dependence ]. 2.3 Important Administration Instructions Clobazam tablets can be taken with or without food. Clobazam tablets can be administered whole, broken in half along the score, or crushed and mixed in applesauce. 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 ]. 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 , Clinical Pharmacology ]. 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 tablets in patients with severe renal impairment or end stage renal disease (ESRD). It is not known if clobazam or its active metabolite, N-desmethylclobazam, is dialyzable [see Use in Specific Populations , Clinical Pharmacology ]. 2.7 Dosage Adjustments in Patients with Hepatic Impairment Clobazam is hepatically metabolized; however, there are limited data to characterize the effect of hepatic impairment on the pharmacokinetics of clobazam. For this reason, proceed slowly with dosing escalations. For patients with mild to moderate hepatic impairment (Child-Pugh score 5 to 9), the starting dose should be 5 mg/day in both weight groups. Then titrate patients according to weight, but to half the dose presented in Table 1, as tolerated. If necessary and based upon clinical response, start an additional titration on day 21 to the maximum dose (20 mg/day or 40 mg/day, depending on the weight group). There is inadequate information about metabolism of clobazam in patients with severe hepatic impairment. Therefore no dosing recommendation in those patients can be given [see Use in Specific Populations , Clinical Pharmacology ].

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.

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 ] Abuse, Misuse, and Addiction [see Warnings and Precautions ] Dependence and Withdrawal Reactions [see Warnings and Precautions ] Potentiation of Sedation from Concomitant Use with Central Nervous System Depressants [see Warnings and Precautions ] Somnolence or Sedation [see Warnings and Precautions ] Serious Dermatological Reactions [see Contraindications , Warnings and Precautions ] Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS)/Multiorgan Hypersensitivity [see Warnings and Precautions )] Suicidal Behavior and Ideation [see Warnings and Precautions ] Neonatal Sedation and Withdrawal Syndrome [ see Warnings and Precautions ] Adverse reactions that occurred at least 10% more frequently than placebo in any clobazam dose included constipation, somnolence or sedation, pyrexia, lethargy, and drooling To report SUSPECTED ADVERSE REACTIONS, contact Upsher-Smith Laboratories, LLC at 1-855-899-9180 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 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 ]. 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 Placebo N=59 % Low Maximum daily dose of 5 mg for ≤30 kg body weight; 10 mg for >30 kg body weight N=58 % Medium Maximum daily dose of 10 mg for ≤30 kg body weight; 20 mg for >30 kg body weight N=62 % High Maximum daily dose of 20 mg for ≤30 kg body weight; 40 mg for >30 kg body weight N=59 % All Clobazam N=179 % 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 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 depression Skin and Subcutaneous Tissue Disorders: Rash, urticaria, angioedema, and facial and lip edema

Alcohol: Increases blood levels of clobazam by about 50% Drugs metabolized by CYP2D6: Lower doses of these drugs may be required when used concomitantly with clobazam Strong or Moderate CYP2C19 Inhibitors: Dosage adjustment of clobazam may be necessary 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 ].

7.2 CNS Depressants and Alcohol Concomitant use of clobazam with other CNS depressants may increase the risk of sedation and somnolence [see Warnings and Precautions ]. Alcohol, as a CNS depressant, will interact with clobazam 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 ]. 7.3 Effect of Clobazam on Other Drugs Hormonal Contraceptives Clobazam is a weak CYP3A4 inducer. As some hormonal contraceptives are metabolized by CYP3A4, their effectiveness may be diminished when given with clobazam. Additional non-hormonal forms of contraception are recommended when using clobazam [see Clinical Pharmacology , Patient Counseling Information ]. Drugs Metabolized by CYP2D6 Clobazam inhibits CYP2D6. Dose adjustment of drugs metabolized by CYP2D6 may be necessary [see Clinical Pharmacology ]. 7.4 Effect of Other Drugs on Clobazam 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 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 ].

Pregnancy: Based on animal data, may cause fetal harm 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 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 ]. 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 pre- and 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.

Lactation Risk Summary Clobazam 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 clobazam and any potential adverse effects on the breastfed infant from clobazam 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 clobazam 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 ]. 8.4 Pediatric Use Safety and effectiveness in patients less than 2 years of age have not been established. 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, the initial dose in elderly patients should be 5 mg/day. Patients should be titrated initially to 10 to 20 mg/day. Patients may be titrated further to a maximum daily dose of 40 mg if tolerated [see Dosage and Administration , Clinical Pharmacology ]. 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 , Clinical Pharmacology ]. 8.7 Renal Impairment The pharmacokinetics of clobazam were evaluated in patients with mild and moderate renal impairment. There were no significant differences in systemic exposure (AUC and C max ) between patients with mild or moderate renal impairment and healthy subjects. No dose adjustment is required for patients with mild and moderate renal impairment. There is essentially no experience with clobazam in patients with severe renal impairment or ESRD. It is not known if clobazam or its active metabolite, N-desmethylclobazam, is dialyzable [see Dosage and Administration , Clinical Pharmacology ]. 8.8 Hepatic Impairment Clobazam is hepatically metabolized; however, there are limited data to characterize the effect of hepatic impairment on the pharmacokinetics of clobazam. For this reason, dosage adjustment is recommended in patients with mild to moderate hepatic impairment (Child-Pugh score 5 to 9). There is inadequate information about metabolism of clobazam in patients with severe hepatic impairment [see Dosage and Administration , Clinical Pharmacology ].