Clobazam in pediatric drug-resistant epilepsy: from pharmacology to clinical practice.

CYP2C19

Clobazam demethylation to N-desmethylclobazam depends on CYP2C19: poor metaboliser status increases exposure to the active metabolite.

This review surveys clobazam in paediatric epileptology: pharmacological mechanisms, pharmacokinetics, efficacy by syndrome, safety and treatment individualisation. This 1,5-benzodiazepine, FDA-approved in 2011 as adjunctive therapy for seizures in Lennox-Gastaut syndrome from age 2, is also used in Dravet syndrome, epilepsy with myoclonic-atonic seizures and epileptic encephalopathy with spike-wave activation in sleep. Across the reviewed studies, adjunctive clobazam achieved at least 50% seizure reduction in about 53% of children and seizure freedom in about 24%, with the strongest evidence in Lennox-Gastaut syndrome, supported by randomised trials. CYP2C19 poor metaboliser status significantly increases N-desmethylclobazam exposure, supporting genotype-guided dose initiation.

Synthesis written by Geno'X. For the full original abstract, please refer to the source publication.

This is a review without an explicit search strategy or study count, so it cannot inherit the strength of the trials it cites: the 53% responder rate is an informal aggregation, not a pooled estimate. Its practical value is nonetheless real, since clobazam and CYP2C19 form one of the few pairs where genotype and therapeutic drug monitoring complement each other well in children, with the active metabolite accumulating in poor metabolisers. In practice, the message is not to wait for somnolence before measuring N-desmethylclobazam in a child who responds or tolerates poorly.

Analysis by Dr Thibaut Benquey