Background and purpose A double-blind placebo-controlled study of eszopiclone found significant, sustained improvement in sleep and daytime function. The 6-month open-label extension phase is described herein. Patients and methods Adults (21–64) with primary insomnia who reported sleep duration 30 min/night were included. Patient-reported endpoints included sleep and daytime function. Safety and compliance were assessed at monthly clinic visits. The final double-blind month was used as the baseline for efficacy analyses of the open-label period. Results Patients who were initially randomized to double-blind placebo and then switched to open-label eszopiclone (n=111) significantly reported the following: (1) decreased sleep latency, wake time after sleep onset, and number of awakenings; (2) increased total sleep time and sleep quality; and (3) improved ratings of daytime ability to function, alertness and sense of physical well-being compared to baseline (P≤0.0001 all monthly endpoints). There was no evidence of tolerance on any measure in either group. These subjects (n=360) sustained the double-blind treatment gains for all sleep and daytime parameters, with further significant improvement in a number of measures. Eszopiclone was well tolerated in both groups; unpleasant taste was the only undesirable effect reported by >5% of patients. Conclusions The significant improvements in sleep and daytime function were evident in those switched from double-blind placebo to 6 months of open-label eszopiclone therapy and were sustained during the 6 months of open-label treatment for those receiving prior double-blind eszopiclone. During 12 months of nightly treatment, eszopiclone 3 mg was well tolerated; tolerance was not observed.
