Pharm 101: Clonazepam
Class
Benzodiazepine
Pharmacodynamics
- Long-acting benzodiazepine
- Binds to GABA-A:
- Potentiates GABAergic inhibition through hyperpolarisation
- Increases frequency of chloride channel opening
- Acts throughout the brain, but the distribution of different GABA-A receptor isoforms varies across the CNS
Pharmacokinetics
- Bioavailability > 80%
- Peak concentrations in 1-4 hours
- 86% protein bound
- Lipid soluble and crosses blood brain barrier effectively
- Extensively metabolised in liver to inactive metabolites
- Half life 12-56 hours
Clinical uses
- One of the most potent anticonvulsant agents known:
- Absence seizures
- Myoclonic seizures
- Infantile spasms
- Sedative-hypnotic
- Anxiolytic
Adverse effects
- Sedation, especially on initiation of therapy
- Toxicity and adverse effects are similar to diazepam
Further Reading
- Nickson C. Status Epilepticus. LITFL
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MBBS (UWA) CCPU Emergency Medicine Trainee with interests in medical education, ECG interpretation, and the use of point-of-care ultrasound in the undifferentiated patient. Co-author of the LITFL ECG Library | Twitter |