Efficacy of eight months of nightly zolpidem: a prospective placebo-controlled study.

To evaluate the long-term (8 months) efficacy of zolpidem in adults with chronic primary insomnia using polysomnography. Randomized, double-blind, placebo-controlled clinical trial. Sleep disorders and research center. Healthy participants (n = 91), ages 23-70, meeting DSM-IV-TR criteria for primary insomnia. Nightly zolpidem, 10 mg (5 mg for patients > 60 yrs) or placebo 30 minutes before bedtime for 8 months. 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. In adults with primary insomnia, nightly zolpidem administration remained efficacious across 8 months of nightly use. ClinicalTrials.gov Identifier: NCT01006525; Trial Name: Safety and Efficacy of Chronic Hypnotic Use; http://clinicaltrials.gov/ct2/show/NCT01006525.