Midazolam for intramuscular premedication: dose-effect relationships compared to diazepam, fentanyl and fentanyl-droperidol in a placebo controlled study.

The clinical effects of midazolam (7.5, 10 and 15 mg), diazepam 10 mg, fentanyl 0.1 mg and fentanyl 0.1 mg-droperidol 5 mg, administered intramuscularly for surgical premedication, were compared in a double-blind placebo-controlled study. The degree of sedation provided by midazolam was significantly superior to diazepam, fentanyl or placebo. The largest dose of midazolam also impaired the lucidity of the patients and induced a moderate degree of muscular hypotony. A dose-effect relationship was observed only for the sedative effects of midazolam 60 min after administration. Midazolam scored consistently better than diazepam, fentanyl, placebo and fentanyl-droperidol for incidence of amnesia, stability of cardiovascular measurements and physician's acceptance. In all treatment groups, including placebo, anxiety decreased significantly with time. However, if expressed as percentage change, the greatest decrease occurred in the midazolam 15 mg group compared to all other treatments. Midazolam appeared to be a more effective premedicant than diazepam, analgesics or placebo. The intensity of the combined central nervous system effects suggested the dose of 10 mg might be the most suitable for intramuscular premedication.