Clonazepam

Clonazepam

Clonazepam (Rivotril)

Mechanism of action

Benzodiazepine and anticonvulsant.

Acts on benzodiazepine receptor via GABA-A receptor and enhances its inhibitory effect through increased frequency of chloride channel opening.

Causes sedation, anxiolysis, anterograde amnesia, muscle relaxation and has an anticonvulsant effect. At higher doses causes respiratory depression. Effects are dose-related.

Indications and dose

Side-effects

Vomiting

Respiratory depression

Confusion

Drowsiness; excess sedation

Paradoxical agitation (more common in elderly)

Cardiovascular depression

Precautions

Metabolised by liver - may need reduced dose in liver failure.

Additive effects with other CNS depressant drugs.

Respiratory and cardiovascular depression can be more profound in cardiopulmonary disease.

Pharmacokinetics

Routes: Oral, intravenous, intramuscular, by rectum

Onset: 20-40 minutes

Duration: ≤12 hours

Bioavailability: 90%

Metabolism: Hepatic

Half-life of elimination: 12-56 hours

Excretion: Urine

Reversal agent

Flumazenil - benzodiazepine antagonist.

Medicinal forms

Tablet - 0,5 and 2 mg tablets.

Oral suspension

Oral solution

I.v. - 1 vial = 1mg/1ml

References

1) https://litfl.com/pharm-101-clonazepam/ 

2) https://bnf.nice.org.uk/drugs/clonazepam/ 

3) https://www.uptodate.com/contents/clonazepam-drug-information?search=clonazepam&source=panel_search_result&selectedTitle=1~124&usage_type=panel&kp_tab=drug_general&display_rank=1#F56287443