The efficacy and safety of three doses of
zaleplon, a novel non-
benzodiazepine hypnotic, were compared with those of placebo in outpatients with
insomnia in this 4-week study, using
zolpidem 10 mg as active comparator. Postsleep questionnaires were used to determine treatment effects on the patient's perception of sleep, as well as any development of pharmacological tolerance during
therapy or
rebound insomnia or
withdrawal symptoms upon discontinuation of
therapy. During week 1, sleep latency was significantly shorter with
zaleplon 5, 10, and 20 mg compared to placebo. The significant decrease in sleep latency persisted through week 4 with
zaleplon 20 mg, and was again evident with
zaleplon 10 mg at week 3.
Zaleplon 20 mg also had significant effects on sleep duration, number of awakenings, and sleep quality compared to placebo. No pharmacological tolerance developed during treatment with
zaleplon and there were no indications of
rebound insomnia or
withdrawal symptoms after treatment discontinuation.
Zolpidem 10 mg had significant effects on sleep latency, sleep duration, and sleep quality compared to placebo. However, a significantly greater incidence of
withdrawal symptoms and a suggestion of sleep difficulty
after treatment discontinuation (
rebound insomnia) for all sleep measures was seen with
zolpidem compared to placebo. There was no significant difference in the frequency of adverse events with active treatment compared to placebo. These results show that
zaleplon provides effective treatment of
insomnia with a favourable safety profile.