Temazepam: a review of its pharmacological properties and therapeutic efficacy as an hypnotic.

Temazepam is a benzodiazepine drug which is a minor metabolite of diazepam. In clinical studies using subjective evaluation methods it was effective for maintaining sleep and increasing total sleep time. However, sleep laboratory studies did not show a significant effect on some sleep parameters, especially sleep induction. Temazepam has a relatively short half-life (about 5 to 11 hours, longer in some subjects and in the elderly), and no active metabolites of clinical importance, and thus may be considered more suitable for use as an hypnotic than longer acting drugs such as diazepam, nitrazepam or flurazepam when residual sedative effects the next day are not desirable. Indeed, few residual effects on morning performance appear to occur with usual single doses of temazepam, although at the upper end of the recommended dosage range (30 mg or more) some evidence of impaired psychomoter and cognitive function in the morning has been reported. Whether or not temazepam is likely to produce "hangover" with repeated night-time administration needs further clarification. While a call for a large number of controlled trials may not be justifiable in evaluating a new hypnotic, a few well designed additional comparative studies in insomniac subjects are needed to assess adequately the relative merits of temazepam (particularly with regard to sleep onset) compared with other benzodiazepine hypnotics, especially those which are short- or intermediate-acting.