Flumazenil

How it works

It is a competitive antagonist at the benzodiazepine binding site of the GABA-A receptor, displacing benzodiazepines and reversing their sedative and respiratory effects.

Prescribing in practice

• It can precipitate seizures and acute withdrawal, so it must be avoided in benzodiazepine-dependent patients, in mixed overdoses involving pro-convulsant drugs and where benzodiazepines are controlling seizures.
• Its duration of action is shorter than that of many benzodiazepines, so re-sedation can occur and the patient must be observed for an adequate period.
• It is not a substitute for airway management and supportive care in overdose.

Monitoring

Monitor conscious level, respiration and for re-sedation or seizure activity for a sufficient period after administration.

Counselling the patient

• This medicine reverses the effects of a sedative and may wake you quickly.
• Drowsiness can return as it wears off, so you will be observed for a time.
• Do not drive or make important decisions for the rest of the day.

Evidence & guidelines

Flumazenil's role and its seizure risk in dependence and mixed overdose are highlighted in UK toxicology guidance (TOXBASE).