Dose-response studies of quazepam

Quazepam, an investigational benzodiazepine, was evaluated in doses of 7.5, 15, and 30 mg in a 12-night protocol including four nights of drug trial. All three doses were effective in inducing and maintaining sleep, with the highest degree of effectiveness after the first drug night. Carry-over effectiveness, which was seen after withdrawal of all three doses, persisted throughout the withdrawal period after the 30-mg dose. Quazepam's effects during both drug use and withdrawal appeared to be dose related; 15 mg induced a greater reduction in wake time after sleep onset than the 7.5-mg dose, and 30 mg induced even greater differences in both wake time after sleep onset and total wake time. Subjective reports of improved sleep were in general agreement with the objective data at each dose level. Side effects appeared to be dose related in terms of severity. The efficacy and comparatively less severe side effects of the 7.5- and 15-mg doses of quazepam suggest that these doses may be optimal when the drug is considered for the adjunctive treatment of insomnia.