Effect of Pregabalin on Sleep Efficiency and Maintenance in Fibromyalgia Patients

AUSTIN, TXFibromyalgia patients treated with pregabalin showed improvements in measure of sleep efficiency and quality and also reported reduced pain, according to results of a study presented at the American Pain Society's 30th Annual Scientific Meeting.

Sleep problems are common among fibromyalgia patients and contribute to fibromyalgia-related fatigue and pain. Malca Resnick, PhD, and colleagues from Pfizer Inc., New York,  sought to assess the effect of pregabalin on objective and subject rated measures of sleep, and subject-rated daily pain (0–10; “no pain” to “worst possible pain”) in patients with fibromyalgia. This randomized, double-blind, placebo-controlled, two-treatment, two-period crossover study enrolled patients ≥18 years with fibromyalgia and sleep maintenance difficulties and randomized them in a 1:1 ratio to pregabalin 300–450mg/day or placebo for crossover Period 1; and vice versa for Period 2.

Subjects were required to meet subjective and objective sleep disturbance criteria prior to randomization. Each crossover period had a dose-adjustment (to Day 14 of period) and dose maintenance (to Day 29 of period) phase, with a two-week taper/washout between period. Total sleep time (TST) was recorded by polysomnography (PSG) at baseline and during two consecutive nights at the end of Period 1 (Day 31) and Period 2 (cumulative Day 73). Subject-rated measures of sleep efficacy were recorded daily by interactive voice response system (IVRS) diary, subjective-TST (sTST) and by sleep quality measured on an 11-point scale from 0–10 (“very poor” to “excellent”). Objective- and patient-rated endpoints were analyzed using a linear mixed-effects model including sequence, treatment as fixed factors, and subject within sequence and within-subject error as random factors.

Of the total 119 patients, 59 were randomized to the pregabalin-to-placebo sequence, and 60 to the placebo-to-pregabalin sequence. The mean duration of fibromyalgia at baseline was 4.2yrs (range 0–26.3yrs). Subjects recorded sleep disturbance at baseline and their baseline pain scores were 6.7±1.63 for the placebo-to-pregabalin group and 6.6±1.62 for the pregabalin-to-placebo crossover group. Patients in the two randomization sequences had similar PSG and patient-rated sleep characteristics prior to treatment. Pregabalin significantly shortened wake after sleep onset (WASO) by 19 minutes, increased TST by >25 minutes, and shortened latency to persistent sleep (LPS) by seven minutes, vs. treatment with placebo. See Table.

During all treatment weeks, pregabalin treatment increased sTST vs. placebo treatment as demonstrated by Week 4 LS mean difference: 25.4 (15.0–35.9; 95% CI); P<0.0001 and by sleep quality: 0.89 (0.51–1.26); P≤0.0001. Daily pain scores were also reduced during all treatment weeks with pregabalin; Week 4 difference vs. placebo: -0.52 (-0.9 to -0.14); P=0.008.

The study authors concluded that fibromyalgia subjects treated with pregabalin at doses approved for the management of fibromyalgia recorded clinically meaningful improvements in PSG measures of sleep. Patients also reported meaningful improvements in sleep duration and quality, and reduced daily pain compared with placebo. This study was supported by Pfizer Inc.