The acute effects of zolpidem compared to diazepam and lorazepam using radiotelemetry.

The present study used a radiotelemetric method to compare the muscle relaxant, hypothermic and locomotor depressant actions of the imidazopyridine zolpidem, with those of the benzodiazepines lorazepam and diazepam. Rats, n=7 per group, were divided into 3 dose-dependent treatment groups (highest, middle, and lowest). Each rat within a treatment group received a single dose of diazepam, lorazepam, zolpidem and vehicle. All three drugs induced dose-dependent decreases in body temperature, locomotor activity and electromyographic (EMG) activity. Administration of zolpidem (5 and 10 mg/kg) resulted in maximal decrements in locomotor activity that were comparable to those elicited by both diazepam (10 and 20 mg/kg) and lorazepam (12.5 and 25 mg/kg). Zolpidem (10 mg/kg) decreased EMG activity levels to approximately 45% of vehicle treated controls; a value similar to that induced by diazepam (2.5 mg/kg). These data suggest that the imidazopyridine zolpidem has a similar profile of acute effects in comparison to the benzodiazepines diazepam and lorazepam. However, the relative magnitude of the effects differed, with zolpidem producing less hypothermia and muscle relaxation than the two benzodiazepines.