clobazam clobazam clobazam, sold under the brand names frisium, onfi and others, is a benzodiazepine class medication that was patented in 1968. clobazam was first synthesized in 1966 and first published in 1969. clobazam was originally marketed as an anxioselective anxiolytic since 1970, and an anticonvulsant since 1984. the primary drug-development goal was to provide greater anxiolytic, anti-obsessive efficacy with fewer benzodiazepine-related side effects. clobazamclinical datatrade namesfrisium, urbanol, onfi, othersahfs/drugs.commonographmedlineplusa612008license data eu ema: by inn us dailymed: clobazam us fda: clobazam pregnancycategory au: c routes ofadministrationby mouthdrug classbenzodiazepineatc coden05ba09 (who) legal statuslegal status au: s4 (prescription only) ca: schedule iv de: prescription only (anlage iii for higher doses) nz: class c uk: class c us: schedule iv in general: ℞ (prescription only) pharmacokinetic databioavailability87% (oral)protein binding80–90%metabolismlivermetabolites n-desmethylclobazam 4′-hydroxyclobazam onset of action0.5–4 hourselimination half-life clobazam: 36–42 hours n-desmethylclobazam: 59–82 hours excretion kidney (82%) feces (11%) identifiers iupac name 7-chloro-1-methyl-5-phenyl-1,5-benzodiazepine-2,4-dione cas number22316-47-8 ypubchem cid2789iuphar/bps7149drugbankdb00349 ychemspider2687 yunii2mro291b4ukeggd01253 ychebichebi:31413 ychemblchembl70418 ycomptox dashboard (epa)dtxsid2046759 echa infocard100.040.810 chemical and physical dataformulac16h13cln2o2molar mass300.74 g·mol−13d model (jsmol)interactive image smiles clc1=cc(n(c2=cc=cc=c2)c(cc(n3c)=o)=o)=c3c=c1 inchi inchi=1s/c16h13cln2o2/c1-18-13-8-7-11(17)9-14(13)19(16(21)10-15(18)20)12-5-3-2-4-6-12/h2-9h,10h2,1h3 ykey:cxoxhmzgekvpmt-uhfffaoysa-n y (verify) medical uses clobazam is used for its anxiolytic effect, and as an adjunctive therapy in epilepsy. as an adjunctive therapy in epilepsy, it is used in patients who have not responded to first-line drugs and in children who are refractory to first-line drugs. it is unclear if there are any benefits to clobazam over other seizure medications for children with rolandic epilepsy or other epileptic syndromes. it is not recommended for use in children between the ages of six months and three years, unless there is a compelling need. in addition to epilepsy and severe anxiety, clobazam is also approved as a short-term (2–4 weeks) adjunctive agent in schizophrenia and other psychotic disorders to manage anxiety or agitation. clobazam is sometimes used for refractory epilepsies. however, long-term prophylactic treatment of epilepsy may have considerable drawbacks, most importantly decreased antiepileptic effects due to drug tolerance which may render long-term therapy less effective. other antiepileptic drugs may therefore be preferred for the long-term management of epilepsy. furthermore, benzodiazepines may have the drawback, particularly after long-term use, of causing rebound seizures upon abrupt or over-rapid discontinuation of therapy forming part of the benzodiazepine withdrawal syndrome. clobazam is approved in canada for add-on use in tonic-clonic, complex partial, and myoclonic seizures. clobazam is approved for adjunctive therapy in complex partial seizures, certain types of status epilepticus, specifically the mycolonic, myoclonic-absent, simple partial, complex partial, and tonic varieties, and non-status absence seizures. it is also approved for the treatment of anxiety. in india, clobazam is approved for use as an adjunctive therapy in epilepsy, and in acute and chronic anxiety. in japan, clobazam is approved for adjunctive therapy in treatment-resistant epilepsy featuring complex partial seizures. in new zealand, clobazam is marketed as frisium in the united kingdom clobazam (frisium) is approved for short-term (2–4 weeks) relief of acute anxiety in patients who have not responded to other drugs, with or without insomnia and without uncontrolled clinical depression. it was not approved in the united states until october 25, 2011, when it was approved for the adjunctive treatment of seizures associated with lennox-gastaut syndrome in patients 2 years of age or older. contraindications clobazam should be used with great care in patients with the following disorders: myasthenia gravis. sleep apnea. severe liver diseases such as cirrhosis and hepatitis. severe respiratory failure. benzodiazepines require special precaution if used in the elderly, during pregnancy, in children, alcohol or drug-dependent individuals, and individuals with comorbid psychiatric disorders. side effects in september 2020, the u.s. food and drug administration (fda) required the boxed warning be updated for all benzodiazepine medicines to describe the risks of abuse, misuse, addiction, physical dependence, and withdrawal reactions consistently across all the medicines in the class. common common side effects include fever, drooling, and constipation. post-marketing experience hives. rashes. warnings and precautions in december 2013, the fda added warnings to the label for clobazam, that it can cause serious skin reactions, stevens–johnson syndrome, and toxic epidermal necrolysis, especially in the first eight weeks of treatment. drug interactions alcohol increases bioavailability by 50%; compounded depressant effect may precipitate life-threatening toxicity. cimetidine increases the effects of clobazam. valproate. overdose overdose and intoxication with benzodiazepines, including clobazam, may lead to cns depression, associated with drowsiness, confusion, and lethargy, possibly progressing to ataxia, respiratory depression, hypotension, and coma or death. the risk of a fatal outcome is increased in cases of combined poisoning with other cns depressants, including alcohol. abuse potential and addiction