Effect of pregabalin on sleep in patients with fibromyalgia and sleep maintenance disturbance: A randomized, placebo-controlled, 2-way crossover polysomnography study

Objective. To assess the effect of pregabalin on polysomnographic (PSG) measures of sleep and patient-rated sleep, tiredness, and pain in fibromyalgia patients. Methods. We performed a randomized, double-blind, placebo-controlled, 2-period crossover PSG study. Patients ages >= 18 years with fibromyalgia satisfied subjective and objective sleep disturbance criteria prior to randomization. Eligible patients were randomized (1: 1) to pregabalin (300-450 mg/day) or placebo for crossover period 1, and vice versa for period 2. Each crossover period comprised a dose-adjustment and dose-maintenance phase, with a 2-week taper/washout between periods. In-laboratory PSGs were recorded during 2 consecutive nights at screening and at the end of each crossover period. The primary end point was the difference in sleep maintenance defined by PSG-recorded wake after sleep onset (WASO; minutes) between 4 weeks of treatment with pregabalin and with placebo. Other PSG measures; patient-rated sleep, tiredness, and pain; and tolerability were assessed. Results. Of 119 patients randomized (103 women [86.6%], mean age 48.4 years), 102 (85.7%) completed both periods. Patients treated with pregabalin showed a reduction in PSG-determined WASO versus treatment with placebo (week 4 difference: -19.2 minutes [95% confidence interval (95% CI) -26.7, -11.6]; P < 0.0001). Pain score improved (decreased) with pregabalin versus placebo treatment at all 4 weeks (week 4 difference: -0.52 [95% CI -0.90, -0.14]; P = 0.0084). Modest (rho = < 0.3) but significant correlations were found between PSG sleep assessments and ratings of pain and sleep quality. Frequently reported all-causality adverse events (pregabalin versus placebo) were: dizziness (30.4% versus 9.9%), somnolence (20.5% versus 4.5%), and headache (8.9% versus 8.1%). Conclusion. Patients with fibromyalgia treated with pregabalin had statistically significant and meaningful improvements in sleep, as assessed by PSG. Patients with fibromyalgia also reported decreased daily pain. Pregabalin was well tolerated.