Reversal of central benzodiazepine effects by flumazenil after intravenous conscious sedation with diazepam and opioids: Report of a double-blind multicenter study

The efficacy and safety of a new benzodiazepine antagonist, flumazenil, were assessed in a double-blind multicenter study. Flumazenil (mean dose, 0.76 mg) or placebo (mean dose, 8.9 ml) was administered intravenously to 130 and 67 patients, respectively, who had been given diazepam in conjunction with an opioid (fentanyl, meperidine, or morphine) for the induction and maintenance of intravenous conscious sedation for diagnostic or therapeutic surgical procedures. The group assessable for efficacy comprised 122 patients treated with flumazenil and 64 patients given placebo. After 5 minutes, 80/115 (70%) flumazenil-treated patients, compared with 21/63 (33%) placebo-treated patients, were completely awake and alert, as indicated by a score of 5 on the Observer's Assessment of Alertness/Sedation Scale. Ninety-five percent of patients in each group who attained a score of 5 at the 5-minute assessment showed no loss of alertness throughout the 180-minute assessment period. Flumazenil-treated patients also performed significantly better on the Finger-to-Nose Test and the recall of pictures shown at the 5-minute assessment. Flumazenil was well tolerated, with no serious adverse effects reported. Thirty-nine (30%) of flumazenil-treated patients, compared with 17 (25%) of placebo-treated patients had one or more drug-related adverse experiences. The most common adverse effects were nausea and vomiting in the flumazenil group and nausea and injection-site pain in the placebo group. Flumazenil was found to promptly reverse sedation induced by diazepam in the presence of opioids.