Background and purpose: 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.
Patients and methods: 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.
Results: 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.
Conclusions: 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.