Reversal of midazolam sedation with anexate.

Anexate (Ro 15-1788) a specific benzodiazepine antagonist, was assessed for its action in reversing midazolam-induced sedation. Sixty-five patients undergoing prostatic surgery under subarachnoid anaesthesia received midazolam for intraoperative sedation (mean dose 16 mg) followed by either active drug (anexate) or placebo given as a randomized, double-blind i.v. injection. The anexate dose sufficient to reverse sedation (0.36 +/- 0.09 mg), produced immediate and dramatic improvements in ability to comprehend and obey commands, in orientation in time and space and in degree of anterograde amnesia. These changes remained significantly different from the control group for 60 min after injection. There was no effect on arterial pressure, heart rate or ventilatory rate and no anxiety states were observed. After initial complete awakening, sedation increased gradually in drug-treated patients, while in the control group, sedation scores and cognitive testing scores all diminished over the 4-h study period. Anexate used in doses up to 0.5 mg provided safe and effective antagonism of midazolam-induced sedation in a clinical setting.