Pharmacology · Antiseizure medicines
Clobazam !
A 1,5-benzodiazepine used as add-on treatment for Lennox-Gastaut syndrome. It sedates and, with opioids, can stop breathing.
Updated 2026-11-01
The figure shows diazepam, a benzodiazepine that occupies the same site, bound to the human GABA-A receptor (α1β2γ2) with GABA; no structure with clobazam is available.
Mechanism of action
Clobazam binds the benzodiazepine site of the GABA-A receptor, between the α and γ subunits. It makes GABA open the chloride channel more readily, strengthening inhibition. It is a 1,5-benzodiazepine, structurally different from classic 1,4-benzodiazepines such as diazepam.
- Binds the benzodiazepine site of the GABA-A receptor
- GABA opens the chloride channel more readily
- More chloride enters and the neuron is inhibited
- Seizures, including drop attacks, become less frequent
Pharmacokinetics
- Absorption
- Absorbed by mouth
- Metabolism
- In the liver to N-desmethylclobazam, an active metabolite broken down by CYP2C19
- Half-life
- About 36 to 42 hours for clobazam and 71 to 82 hours for N-desmethylclobazam
Indications
- Add-on treatment of seizures of Lennox-Gastaut syndrome Epilepsy and seizures →
Adverse effects
Common
- Sleepiness and sedation
- Tiredness and poor coordination
- Drooling and difficulty speaking or swallowing
- Change in appetite, vomiting and constipation
Contraindications
- Hypersensitivity to clobazam
Key interactions
- Opioids
- Profound sedation, respiratory depression, coma and death
- Alcohol and other central nervous system depressants
- More sedation and respiratory depression
- Hormonal contraceptives
- Clobazam can make them less effective; a non-hormonal method is added
- Strong or moderate CYP2C19 inhibitors
- More active metabolite; the dose may need adjustment
What is monitored
- Sedation and breathing, especially with opioids
- Signs of misuse or dependence
- Skin reactions, especially in the first weeks
- Mood and suicidal thoughts
Administration and safety
- Given by mouth as tablets or liquid
- Controlled medicine (benzodiazepine)
- Withdrawn gradually: stopping suddenly can cause withdrawal reactions and seizures
Nursing care
- Check alertness, breathing and swallowing, especially in children with Lennox-Gastaut syndrome
- Ask about opioid use before each new prescription
- Teach the family to report rash, blisters or fever
- Teach not to stop suddenly
Pregnancy and breastfeeding
Use late in pregnancy can cause sedation and withdrawal in the newborn.
Test yourself
Think of the answer, then tap the question to see it.
For which epilepsy syndrome is clobazam mainly used?
Lennox-Gastaut syndrome, as add-on treatment.
Why is clobazam combined with opioids only with great caution?
Benzodiazepines plus opioids can cause profound sedation, respiratory depression, coma and death.
Which enzyme breaks down clobazam's active metabolite?
CYP2C19; poor metabolizers and people on CYP2C19 inhibitors have higher levels of N-desmethylclobazam.
Related drugs
Related conditions
← Back to the class: Antiseizure medicines
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: Clobazam: MedlinePlus Drug Information (MedlinePlus (U.S. National Library of Medicine), 2025); DailyMed - CLOBAZAM tablet (DailyMed (U.S. National Library of Medicine), 2026); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026).
Spotted a mistake?We are always improving for the community. Tell us what is wrong and our team will review it.Report a mistake
Representative model, for educational purposes only.