Eszopiclone coadministered with escitalopram in patients with insomnia and comorbid generalized anxiety disorder

Abstract

Context: Insomnia and generalized anxiety disorder (GAD) are prevalent disorders that may coexist.

Objective: To determine the efficacy of eszopiclone combined with escitalopram oxalate in treating insomnia comorbid with GAD.

Design: Double-blind, randomized, placebo-controlled, parallel-group, add-on therapy 10-week study.

Setting: Multicenter outpatient study from July 2005 to April 2006.

Patients: Adults aged 18 to 64 years meeting DSM-IV-TR criteria for GAD and insomnia.

Interventions: Patients received 10 mg of escitalopram oxolate for 10 weeks and were randomized to also receive either 3 mg of eszopiclone (n = 294) or placebo (n = 301) nightly for 8 weeks. For the last 2 weeks, eszopiclone was replaced with a single-blind placebo.

Main outcome measures: Sleep, daytime functioning, psychiatric measures, and adverse events.

Results: Compared with treatment with placebo and escitalopram, treatment with eszopiclone and escitalopram resulted in significantly improved sleep and daytime functioning (P < .05), with no evidence of tolerance. Patients taking eszopiclone and escitalopram had greater improvements in total Hamilton Anxiety Scale (HAM-A) scores at each week (P < .05) and at weeks 4 through 10 with the insomnia item removed. Clinical Global Impressions (CGI) of Improvement scores were improved with eszopiclone and escitalopram at every point (P < .02), while CGI of Severity of Illness scores were not significantly different after week 1. The HAM-A response (63% vs 49%, respectively, P = .001) and remission (42% vs 36%, respectively, P = .09) rates at week 8 were higher in patients treated with eszopiclone and escitalopram than those treated with placebo and escitalopram, and median time to onset of anxiolytic response was significantly reduced (P < or = .05). After eszopiclone discontinuation, there was no evidence of rebound insomnia, and while treatment differences in anxiety measures were maintained, differences in sleep outcomes were not. Overall adverse event rates were 77.6% with cotherapy and 67.9% with monotherapy. The most common adverse events with cotherapy were unpleasant taste, headache, dry mouth, and somnolence.

Conclusions: Coadministration of eszopiclone and escitalopram was well tolerated and associated with significantly improved sleep, daytime functioning, anxiety, and mood in patients with insomnia and GAD.

Trial registration: clinicaltrials.gov Identifier: NCT00235508.