Hypnotic effects of low doses of quazepam in older insomniacs

To evaluate the efficacy and safety of reduced doses of the benzodiazepine agonist quazepam in older insomniacs, 30 men and women > 60 years old with chronic insomnia were randomly assigned to receive 0, 7.5, or 15 mg quazepam. After two placebo nights, each subject received the appropriate dose for seven consecutive nights, which was followed by two placebo recovery nights. Both doses increased total sleep time relative to placebo during the early (nights 1 and 2) and late (nights 6 and 7) treatment phases. The low dose reduced sleep latency during the late phase, whereas the high dose reduced sleep latency in both early and late treatment phases. These observed hypnotic effects for both doses did not diminish over the seven nights of repeated administration. There also was a continued hypnotic effect during the two nights of placebo recovery for both doses. Analyses of plasma concentrations of quazepam and its metabolites suggested the continued drug effects on sleep during recovery are due to the metabolite desalkylflurazepam. In the safety evaluation done by means of adverse drug event assessments and postsleep questionnaires, the adverse events reported were minimal and not drug or dose related.