Flumazenil: A Benzodiazepine Antagonist

Abstract

Although benzodiazepines have been proven safe and effective for the induction and maintenance of sedation, some instances require the reversal of these events prior to the natural process of metabolism and elimination. Flumazenil, a 1,4-imidazobenzodiazepine, is an antagonist that can reduce or terminate benzodiazepine effects in a dose-dependent manner. The antagonist acts by the competitive inhibition of benzodiazepines at their central nervous system receptor sites. When administered intravenously in incremental doses, flumazenil allows for optimal patient response on an individual basis. Despite its short elimination half-life, small doses of flumazenil are usually effective in producing benzodiazepine reversal. Flumazenil's short duration of activity is due to its rapid hepatic metabolism and elimination. Intravenous antagonist doses of 0.2 mg followed by 0.1 mg/min to a total dose of 1 mg have produced significant results in reversing benzodiazepine sedation. As much as 5 mg of flumazenil have been necessary when treating benzodiazepine or mixed-agent intoxications. In such situations, response rarely exceeds a duration of one hour. If resedation occurs, additional doses or an infusion of the antagonist may provide the desired response. Flumazenil is well tolerated locally as well as systemically. Nausea and vomiting occurring after anesthesia is the most documented adverse effect in both placebo and treatment populations. However, there has been no significant difference in the occurrence of vomiting in placebo compared with flumazenil-treated subjects. Careful observation and slow reversal of central nervous system depression is crucial in the avoidance of benzodiazepine withdrawal in those patients dependent upon these agents. Flumazenil appears to provide a mechanism for the safe and effective reversal of benzodiazepine-induced sedation.(ABSTRACT TRUNCATED AT 250 WORDS)

Altered behavioral responses to gamma‐aminobutyric acid pharmacological agents in a mouse model of Huntington's disease

“…S1). Importantly, a selective and competitive benzodiazepine receptor antagonist (flumazenil, 5 mg/kg) reversed the effect of diazepam in the WT mice (Fig. S1), suggesting that the action of diazepam was mediated via GABA A R. No effect of flumazenil on the R6/2 mice was observed.…”

Adverse Events Associated with Flumazenil Treatment for the Management of Suspected Benzodiazepine Intoxication – A Systematic Review with Meta‐Analyses of Randomised Trials

“…Flumazenil, a 1,4‐imidazobenzodiazepine, blocks the benzodiazepine receptors, with only a weak intrinsic action (GABA‐A receptor complex) . Flumazenil is used in the treatment of benzodiazepine overdose, primarily to reverse the sedative effect of benzodiazepines and prevent respiratory depression .…”

Fatores Relacionados à Utilização de Flumazenil em Pacientes Hospitalizados

“…O fármaco flumazenil (8-fluoro-5,6-diidro-5-metil-6-oxo-4H-imidazol [1,5a] [1,4] benzodiazepina -3-carboxilato de etila) bloqueia, por inibição competitiva, os efeitos centrais de substâncias que agem ao nível dos receptores benzodiazepínicos 13 . É classificado como antídoto pela Anatomical Therapeutic Chemical (ATC) sob o código V03AB25.…”