An evaluation of the efficacy and safety of eszopiclone over 12 months in patients with chronic primary insomnia

Sleep Med. 2005 Nov;6(6):487-95. doi: 10.1016/j.sleep.2005.06.004. Epub 2005 Oct 17.


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 <6.5 h/night or sleep latency >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<or=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 3mg was well tolerated; tolerance was not observed.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Azabicyclo Compounds
  • Cross-Over Studies
  • Drug Administration Schedule
  • Female
  • Follow-Up Studies
  • Humans
  • Hypnotics and Sedatives / administration & dosage*
  • Hypnotics and Sedatives / adverse effects
  • Male
  • Middle Aged
  • Piperazines / administration & dosage*
  • Piperazines / adverse effects
  • Sleep Initiation and Maintenance Disorders / drug therapy*
  • Treatment Outcome


  • Azabicyclo Compounds
  • Hypnotics and Sedatives
  • Piperazines
  • zopiclone