Flumazenil: A specific benzodiazepine antagonist

Flumazenil is a specific benzodiazepine (BZD) antagonist which inhibits the effects of BZD agonists by competing for the receptor site in the central nervous system. It has completed clinical trials in the United States and received final approval from the U.S. Food and Drug Administration for release in January 1992. Following intravenous injection, clinically apparent arousal usually occurs within 1 to 5 minutes and is maintained for approximately 2 hours in patients either anesthetized or sedated with BZDs. This illustrates the potential for resedation and the importance of careful monitoring following administration. Flumazenil does not possess clinically significant intrinsic pharmacologic activity. Because of its specificity for the BZD receptor, it has no effect on the actions of other non-BZD sedatives and anesthetics. Its efficacy has been established not only in conscious sedation and general anesthesia but also in the differential diagnosis of unknown/suspected BZD intoxication. To date, it has been well tolerated in most patients, with few reported side effects and has no effect on the pharmacokinetic profiles of coadministered drugs. Flumazenil is a promising, effective, and short-acting BZD antagonist that should provide an additional degree of safety whenever the undesirable effects of BZD agonists occur.