Pregabalin improves fibromyalgia related sleep disturbance

Patients with fibromyalgia manifest disturbed sleep characteristics which differentiate them from primary insomnia patients and healthy volunteers-namely more frequent but shorter wake bouts. This 2-period, cross-over study investigated the effect of pregabalin (150-450mg/day) and placebo on wake- and sleep-bout parameters in FM patients &ge18y with difficulty maintaining sleep, but without history of circadian rhythm or other sleep disorder. Polysomnography was performed during 2-consecutive nights at baseline, and the end of each treatment period. Patients were selected according to study-specific criteria for sleep-maintenance problems, including polysomnography-determined wake-after-sleep-onset (WASO) &ge45mins and total-sleep-time (TST) 3.0-6.5hrs. In addition to traditional sleep measures, duration and frequency of sleep/wake bouts were analyzed. Data are least-squares (LS) mean [standard error], or LS-mean difference (pregabalin vs. placebo [95% confidence interval]). Of 119 patients randomized (103 [87%] female; 48.4y), data were available for 103 when treated with pregabalin and 106 treated with placebo. In addition to a treatment benefit with pregabalin on traditional polysomnography measures (decreased WASO and latency to persistent sleep; increased TST, sleep efficiency, and Stage 3-4 sleep), pregabalin-treated patients showed increased mean duration of sleep bouts (15.25 [0.63] vs. 11.58 [0.62] mins; difference: +3.67 [2.22, 5.12] mins; P<0.0001) and decreased number of wake bouts (33.24 [1.33] vs. 36.85 [1.32]; difference: -3.61 [-6.03, -1.18]; P=0.0039). Patients also showed decreased mean duration of wake bouts (3.4 [0.55] vs. 3.94 [0.55] mins; difference:-0.53 [-1.06, -0.002] mins; P=0.0493). Pregabalin treatment improved sleep parameters characteristics of sleep in FM, namely increased sleep bout duration and decreased wake bouts frequency vs. placebo treatment. Modifying these sleep characteristics may underlie the patient-reported efficacy of pregabalin for improving sleep-quality and -duration in FM.