Efficacy of Eight Months of Nightly Zolpidem: A Prospective Placebo-Controlled Study

Study Objectives: To evaluate the long-term (8 months) efficacy of zolpidem in adults with chronic primary insomnia using polysomnography. Design: Randomized, double-blind, placebo-controlled clinical trial. Setting: Sleep disorders and research center. Participants: Healthy participants (n = 91), ages 23-70, meeting DSM-IV-TR criteria for primary insomnia. Interventions: Nightly zolpidem, 10 mg (5 mg for patients >60 yrs) or placebo 30 minutes before bedtime for 8 months. Measurements and Results: Polysomnographic sleep parameters and morning subject assessments of sleep on 2 nights in months 1 and 8. Relative to placebo, zolpidem significantly increased overall total sleep time and sleep efficiency, reduced sleep latency and wake after sleep onset when assessed at months 1 and 8. Overall, subjective evaluations of efficacy were not shown among treatment groups. Conclusions: In adults with primary insomnia, nightly zolpidem administration remained efficacious across 8 months of nightly use.