Polysomnographic study of intermittent zolpidem treatment in primary sleep maintenance insomnia

Treatment of chronic insomnia with nightly hypnotics is efficacious, but discontinuation is recommended after 1 month, less than the average disease duration. This study was undertaken to determine the efficacy of intermittent administration.

A double-blind study was carried out on 8 patients (age, 32.8 +/- 9 years; 3 men) with primary sleep maintenance insomnia longer than 1 month. Polysomnography of conventional sleep parameters, cyclic alternating patterns (CAPs), and arousals was performed. Perception of sleep quality was assessed on a visual analog scale. After an adaptation night, baselines were recorded followed by 6 consecutive nights of alternating treatment with zolpidem (10 mg) or placebo.

Significant improvements on baseline values (P < 0.0001) were observed on all 3 active treatment nights for total sleep time, sleep efficiency, CAP time, CAP rate, subtype A2, arousals, and arousal index. Deep non-rapid eye movement sleep increased with the second and third doses of active treatment (P < 0.0001). Rapid eye movement sleep increased during the last 3 polysomnographic recordings (P < 0.014). Sleep quality (visual analog scale) improved on all nights after the initial dose of active treatment (P < 0.0001). There was no evidence of rebound insomnia with placebo.

Intermittent treatment with zolpidem in primary insomnia patients improves CAP parameters and arousals, as well as sleep duration and quality, in the absence of rebound insomnia.