A 12-Week, Randomized, Double-Blind, Placebo-Controlled Study Evaluating the Effect of Eszopiclone 2 mg on Sleep/Wake Function in Older Adults with Primary and Comorbid Insomnia

Background: Longer-term pharmacologic studies for insomnia in older individuals are sparse. Objective: To evaluate the efficacy and safety of 12 weeks of nightly eszopiclone in elderly outpatients with insomnia. Methods: Participants (65-85 years) met DSM-IV-TR criteria for insomnia with total sleep times (TST) <= 6 h, and wake time after sleep onset (WASO) >= 45 min. Participants were randomized to 12 weeks of eszopiclone 2 mg (n = 194) or placebo (n = 194), followed by a 2-week single-blind placebo run-out. Subject-reported measures of sleep (sTST, sleep latency [sSL], sWASO) and daytime function (alertness, concentration, wellbeing, ability to function) were assessed. AEs were monitored. Results: Subjects treated with 2 mg eszopiclone slept longer at night on average and at every individual time point compared to baseline than placebo subjects, as measured by TST over the 12-week double-blind period (P < 0.0001). Mean sTST over the double-blind period for eszopiclone-treated subjects was 360.08 min compared to 297.86 min at baseline, a mean change of 63.24 min. Over the double-blind period, eszopiclone-treated subjects also experienced a significantly greater improvement in sSL compared to placebo, with a mean decrease of 24.62 min versus a mean decrease of 19.92 min, respectively (P = 0.0014). Eszopiclone subjects also experienced a significantly greater decrease in WASO (mean decrease of 36.4 min) compared to placebo subjects (decrease of 14.8 min) (P < 0.0001). Post-discontinuation, sleep parameters were statistically improved versus baseline for eszopiclone (P-values <= 0.01), indicating no rebound. The most common AEs (>= 5%) were headache (eszopiclone 13.9%, placebo 12.4%), unpleasant taste (112.4%, 1.5%), and nasopharyngitis (5.7%, 6.2%). Conclusion: In this Phase IV trial of older adults with insomnia, eszopiclone significantly improved patient-reported sleep and daytime function relative to placebo. Improvements occurred within the first week and were maintained for 3 months, with no evidence of rebound insomnia following discontinuation. The 12 weeks of treatment were well tolerated.