Flumazenil
Aliases: Anexate, Lanexat, Mazicon, Romazicon, Ro 15-1788
Categories
Summary
Flumazenil is the benzodiazepine antidote and can abruptly trigger withdrawal or seizures in dependent individuals. It should only be used with seizure management on standby and careful screening for mixed overdoses. Flumazenil competitively blocks the benzodiazepine site on the GABAA receptor. When used on benzodiazepine-tolerant individuals it can precipitate an abrupt, sometimes life-threatening withdrawal characterised by agitation, hypertension and generalised tonic-clonic seizures. Case series show neurologic adverse-event reporting odds ratios >1700 for withdrawal seizures in pharmacovigilance databases.
Dose Information
Light
Common
Strong
Heavy
Onset, Duration & After-effects
| ROA | Onset | Peak | Offset | After Effects |
|---|---|---|---|---|
| Intravenous (Bolus) | 1-2 min | 6-10 min | 1-2 hrs | 6 hrs |
| Intravenous Infusion (Resedation Prevention) | - | - | 60 min | 6 hrs |
| Intranasal (Investigational / Pediatric) | 5-8 min | 10-20 min | 1-2 hrs | 6 hrs |
Tolerance
Build-up
develops over 1–4 weeks of daily use; hypnotic tolerance faster than anxiolytic tolerance
Reset
weeks to months depending on half-life and duration of use; taper recommended
Effects
Positive
Negative
- Nausea or vomiting
- Tremor
- Motor impairment
- Sedation
Positive
- Reduced anxiety
Negative
- Anxiety or panic
- Dysphoria
- Dizziness
- Abrupt return of consciousness
Neutral
- Dulled perception