Dose response effects of zolpidem in normal geriatric subjects.

The dose-related hypnotic effects and effects on memory, performance, and daytime alertness of zolpidem 5, 10, 15, and 20 mg were compared with those of placebo in 30 elderly non-insomniac volunteers in a randomized, placebo-controlled, three-period crossover study. Subjects were randomized into two groups and received either placebo, zolpidem 5 mg, or zolpidem 15 mg or placebo, zolpidem 10 mg, or zolpidem 20 mg for 2 consecutive nights followed by 1 night of placebo during the same 3 nights of 3 consecutive weeks. Polysomnographic results showed statistically significant decreases in sleep latency and increases in sleep efficiency at all doses. Subjective reports also showed improved sleep latency, total sleep time, and sleep quality. REM percent was slightly decreased at doses of 10 and 20 mg. No consistent effects on memory or performance were observed, and the Multiple Sleep Latency Test showed no effects on daytime sleepines. There was no objective evidence of rebound insomnia upon drug discontinuation.