Sustained efficacy of eszopiclone over 6 months of nightly treatment: results of a randomized, double-blind, placebo-controlled study in adults with chronic insomnia.

STUDY OBJECTIVES: To determine the long-term efficacy of eszopiclone in patients with chronic insomnia.

DESIGN: Randomized, double-blind, multicenter, placebo-controlled.

SETTING: Out-patient, with monthly visits.

PATIENTS: Aged 21 to 69 years meeting DSM IV criteria for primary insomnia and reporting less than 6.5 hours of sleep per night, and/or a sleep latency of more than 30 minutes each night for at least 1 month before screening.

INTERVENTIONS: Eszopiclone 3 mg (n = 593) or placebo (n = 195), nightly for 6 months

MEASUREMENTS AND RESULTS: Efficacy was evaluated weekly using an interactive voice-response system. Endpoints included sleep latency; total sleep time; number of awakenings; wake time after sleep onset; quality of sleep; and next-day ratings of ability to function, daytime alertness, and sense of physical well-being. At the first week and each month for the study duration, eszopiclone produced significant and sustained improvements in sleep latency, wake time after sleep onset, number of awakenings, number of nights awakened per week, total sleep time, and quality of sleep compared with placebo (P < or = 0.003). Monthly ratings of next-day function, alertness, and sense of physical well-being were also significantly better with the use of eszopiclone than with placebo (P < or = 0.002). There was no evidence of tolerance, and the most common adverse events were unpleasant taste and headache.

CONCLUSIONS: Throughout 6 months, eszopiclone improved all of the components of insomnia as defined by DSM-IV, including patient ratings of daytime function. This placebo-controlled study of eszopiclone provides compelling evidence that long-term pharmacologic treatment of insomnia is efficacious.