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Antiepileptic — 1,5-Benzodiazepine Pregnancy: Avoid — neonatal withdrawal and floppy infant syndrome; use only if no alternative

Clobazam

Brand names: Frisium, Onfi

Adult dose

Dose: 10–30 mg/day in divided doses or as a single nocte dose
Route: Oral
Frequency: Once to twice daily
Max: 60 mg/day
1,5-benzodiazepine — less sedating than 1,4-benzodiazepines (diazepam, clonazepam). Adjunctive treatment for epilepsy. Particularly used for catamenial epilepsy (cyclical seizure exacerbation around menstruation) at 10 mg/day in the perimenstrual period. Controlled drug (Schedule 4 Part 1).

Paediatric dose

Dose: 0.1–0.3 mg/day/kg
Route: Oral
Frequency: Once to twice daily
Max: 1 mg/kg/day
Children ≥6 months: 0.1–0.3 mg/kg/day in 2 divided doses. Max 1 mg/kg/day.

Dose adjustments

Renal

No specific adjustment — use lower dose and monitor.

Hepatic

Reduce dose and avoid in severe hepatic impairment.

Paediatric weight-based calculator

Children ≥6 months: 0.1–0.3 mg/kg/day in 2 divided doses. Max 1 mg/kg/day.

Clinical pearls

  • Less sedating and less tolerance development than 1,4-benzodiazepines (diazepam, clonazepam) due to partial agonist activity at some GABA-A receptor subtypes
  • Dravet syndrome: clobazam + stiripentol + valproate is a licensed combination — dramatic dose reduction of clobazam required due to stiripentol interaction (N-desmethyl-clobazam accumulates to toxic levels)
  • Catamenial epilepsy: 10 mg/day from day 14–28 of cycle — effective rescue strategy for cyclical seizure worsening

Contraindications

  • Respiratory depression
  • Sleep apnoea
  • Myasthenia gravis
  • Severe hepatic impairment

Side effects

  • Sedation (less than 1,4-benzodiazepines)
  • Tolerance and dependence
  • Cognitive impairment
  • Respiratory depression (less than diazepam)
  • Drooling (children)
  • Behavioural disturbance

Interactions

  • CNS depressants (additive)
  • Opioids (additive respiratory depression)
  • Stiripentol (dramatically increases clobazam/N-desmethyl-clobazam levels — reduce clobazam dose to 25% in Dravet syndrome triple therapy)

Monitoring

  • Seizure diary
  • Sedation and cognitive function
  • N-desmethyl-clobazam levels if on stiripentol

Reference: BNFc; BNF 90; NICE NG217; BNFc; Dravet Syndrome Foundation Guidelines. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

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