Antagonism of diazepam-induced sedative effects by flumazenil in patients after surgery under lumbar spinal or epidural anesthesia

The efficacy and general safety of flumazenil (YM684), a specific benzodiazepine antagonist, have been evaluated. Forty-seven patients scheduled for surgery under lumbar spinal or epidural anesthesia with diazepam sedation received flumazenil at the end of the procedure. Criteria of efficacy were the degree of sedation and antegrade amnesia. Before injection all patients were heavily sedated with the mean dose of 27 mg of diazepam (range 10-50 mg). After the mean dose of 0.21 mg of flumazenil (range 0.2-0.4 mg), all patients were awake or drowsy within 1-6 min but sedation recurred in one patient 1 hour later. The amnesia was eliminated by flumazenil in 34 patients (72%). No serious side-effects or hemodynamic changes were observed after flumazenil. It is concluded that flumazenil is an effective antagonist of sedation induced by diazepam.