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
Pharmacology 101
Top 200 drugs
MBBS FACEM DDU (Emergency) CCPU. Emergency Physician in Melbourne, Australia. Co-Ultrasound Lead for Emergency Medicine at The Alfred Hospital. Special interests in diagnostic and procedural ultrasound, medical education, and ECG interpretation. Editor of the LITFL ECG Library.
