Short-term studies have suggested that newer hypnotic agents, such as zolpidem, produce less rebound insomnia, compared with benzodiazepines. Research reported in European Neuropsychopharmacology (August 2004), however, showed that zolpidem is not superior to the benzodiazepine temazepam with respect to rebound insomnia.

Rebound insomnia may occur after patients stop taking certain sleep medications. A randomized, controlled trial compared the prevalence of rebound insomnia in zolpidem-and temazepam-treated patients after they discontinued treatment for chronic insomnia.

During the initial 4-week treatment period, equivalent doses of both agents were comparably safe and efficacious in improving total sleep time (TST) and sleep onset latency (SOL). After cessation of treatment, the prevalence of rebound insomnia, which was defined by a worsening of TST or SOL, also was similar with both agents. Therefore, it appears that at least one of the newer "Z drugs," zolpidem, has no advantages over temazepam in clinical use for insomnia or for rebound insomnia.