Flumazenil is the first specific benzodiazepine antagonist, used as a specific antidote in known or suspected benzodiazepine overdose treatment .
In addition, flumazenil could be employed to reverse sedation produced by benzodiazepines during general anesthesia and prolonged sedation in intensive care units.
Flumazenil is a specific and competitive antagonist at the central benzodiazepine receptor, reversing all effects of benzodiazepine overdose treatment agonists without tranquillizing or anticonvulsant actions.
Incremental intravenous bolus injections of flumazenil 0.1 to 0.3 mg are the most effective and well tolerated in the diagnosis and benzodiazepine overdose treatment of pure benzodiazepine overdose; additional boluses or an infusion (0.3 to 0.5 mg/h) can be given to prevent patients from relapsing into coma.
Intravenous flumazenil 10 to 20 g/kg is effective in neonates and small children. Intramuscular, oral (20 to 25 mg 3 times daily or as required) and rectal administration may be used as alternatives in long-term regimens.
Patients with mixed-drug overdose require higher doses (up to 2 mg bolus, approximately equal to 1 mg/h infusion) to regain consciousness under benzodiazepine overdose treatment .
Children and the elderly, chronically ill patients, and pregnant women and their fetuses all respond satisfactorily to flumazenil.
The use of flumazenil results in complete awakening with restoration of upper airway protective reflexes and resumption of effective spontaneous respiration, allowing extubation, weaning off mechanical ventilation or the avoidance of endotracheal intubation.
While flumazenil is not associated with haemodynamic adverse effects, caution should be exercised when using this agent in patients who have co-ingested chloral hydrate or carbamazepine or whose ECG shows abnormalities typical to those seen after benzodiazepine overdose treatment with tricyclic anti- depressants (TCAs).
The use of flumazenil in the presence of these drugs can sometimes induce treatable cardiac dysrhythmias. Flumazenil itself does not induce adverse effects of benzodiazepine overdose treatment .
Coma reversal by flumazenil may cause mild, short- lived reactions caused by sudden awakening.
Withdrawal symptoms in long-term benzodiazepine users and seizures in patients who have taken an overdose of TCA or carbamazepine and a benzodiazepine can occur with flumazenil; these symptoms of benzodiazepine overdose treatment are avoidable by utilizing slow flumazenil dose titration.