To investigate the effect of pregabalin on wake and sleep bout parameters.
A post hoc analysis of polysomnography data from a randomized, placebo-controlled, crossover study investigating the effect of pregabalin (150 to 450 mg/d) and placebo on sleep in fibromyalgia (FM). Eligible patients had FM and sleep-maintenance problems, including wake after sleep onset ≥45 minutes and total sleep time (TST) 3.0 to 6.5 hours, but no other sleep/circadian rhythm disorders. Polysomnography was performed for 2 consecutive nights (screening, post-treatment). Wake and sleep bout duration and frequency were derived; a "bout"=consecutive 30-s epochs of sleep or wake.
Of 119 patients randomized (103 [87%] female), data were available for 103 treated with pregabalin and 106 with placebo. Pregabalin versus placebo treatment decreased mean±SD number of wake/sleep bouts (33.24±1.33 vs. 36.85±1.32; difference: -3.61 [95% confidence interval, -6.03, -1.18]; P=0.0039) and increased sleep bout duration (15.25±0.63 vs. 11.58±0.62 min; +3.67 min [2.22, 5.12 min]; P<0.0001). Pregabalin decreased mean duration of wake bouts versus placebo (3.41±0.55 vs. 3.94±0.55 min; -0.53 min [-1.06, -0.002 min]; P=0.0493). An exploratory correlation analysis of treatment effects found stage 1 sleep was negatively correlated with wake and sleep bout duration and positively with wake/sleep bout number; slow wave sleep (%total sleep time) was positively correlated with wake and sleep bout duration and negatively with wake/sleep bout number.
Pregabalin improved sleep parameters characteristic of disturbed sleep in FM, by preventing awakenings and increasing sleep bout duration. These effects are reflected in, and correlated with, a decrease in "light sleep" (stage 1) and an increase in "deep sleep" (slow wave sleep).