Efficacy and tolerability of modified-release indiplon in elderly patients with chronic insomnia: results of a 2-week double-blind, placebo-controlled trial.J Clin Sleep Med 2006; 2(3):309-15JC
Indiplon is a nonbenzodiazepine GABA potentiator, which exhibits pharmacologic selectivity for GABA(A) receptors containing the alpha1 subunit. The aim of the present study was to evaluate the efficacy and safety of a 15-mg nightly dose of modified-release indiplon tablets in elderly patients with primary insomnia characterized by sleep-maintenance difficulties.
Two hundred twenty-nine elderly patients, aged 65 to 85 years, who met Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria for primary insomnia were randomly assigned to 2 weeks of nightly treatment with either indiplon, 15 mg, or placebo in a double-blind, parallel-group design. Daily sleep diaries were completed to collect patient reports of subjective total sleep time, wake time after sleep onset, number of awakenings after sleep-onset, latency to sleep onset, and sleep quality. Patient global impression ratings of various parameters of sleep were assessed on a weekly basis.
The least square mean total sleep time was significantly improved with indiplon versus placebo at week 1 (377 +/- 4 min vs. 328 +/- 4 min; p < .0001) and week 2 (373 +/- 5 min vs. 337 +/- 5 min; p < .0001). Indiplon also significantly improved subjective wake after sleep onset, subjective number of awakenings after sleep onset, subjective sleep-onset latency, sleep quality, and patient global impression ratings of sleep at both weeks 1 and 2. The number and severity of adverse events and rates of discontinuation due to adverse effects were comparable in the indiplon and placebo groups.
In elderly patients with primary insomnia characterized by sleep-maintenance difficulty, indiplon, 15 mg, was well tolerated and significantly improved all patient-reported measures of sleep during 2 weeks of treatment.