Treatment with pregabalin improves sleep parameters in patients with fibromyalgia (FM), including decreasing the number of wake/sleep bouts and increasing total sleep duration, according to research published in The Clinical Journal of Pain.1
Disordered sleep has been implicated in the impairment of descending inhibitory pain pathways that may contribute to abnormal pain sensitization present in FM.2 It has been suggested that improving sleep quantity and quality may reduce symptoms of pain and fatigue frequently seen in patients with FM.
To evaluate the effects of pregabalin treatment on the sleep-wake cycle in patients with FM, Thomas Roth, PhD, and colleagues associated with the Sleep Disorders and Research Center at the Henry Ford Health System, Detroit, Michigan, analyzed data from patients enrolled in a multinational, multicenter, placebo-controlled crossover study.
Patients were randomized 1:1 to receive either pregabalin (150 to 450 mg/day) or placebo for a 14 day period, followed by 2 double-blinded 14 day crossover treatment periods, each including 2-week taper periods between crossover time points.
On 2 consecutive nights at the time of initial patient screening and at the end of each crossover treatment, polysomnography (PSG) was performed, measuring total sleep time (TST), wake after sleep onset (WASO), latency to persistent sleep (LPS), slow wave sleep (SWS), length of time in sleep stages, and the number and duration of sleep or wake bouts. A subjective assessment of pain was obtained by asking study participants to rate the average pain over the past 24 hours on the numerical rating scale (NRS).
Researchers found that in the 119 predominantly female (86.6%) patients with FM randomized to receive study medication, the number of wake/sleep bouts were significantly decreased in those taking pregabalin as compared to placebo (33.24±1.33 vs 36.85±1.32; difference: –3.61 [95% confidence interval, –6.03, –1.18]; P=.0039). The total sleep bout duration was also significantly increased in participants taking pregabalin as compared to placebo (15.25±0.63 vs 11.58±0.62 min; +3.67 min [2.22, 5.12 min]; P<.0001). A small but statistically significant correlation was also found between duration of wake bout and reported NRS scores (0.027, P=.037).
“In an exploratory correlation analysis…Stage 1 sleep correlated negatively with wake bout mean duration (–0.503) and sleep bout mean duration (–0.629) and positively with wake/sleep bout number (0.74; P<.0001 for each),” the authors noted.
Summary and Clinical Applicability
In this study, pregabalin treatment was associated with improved sleep parameters in patients with FM, including decreased number of wake/sleep bouts and increased total sleep bout duration.1, This suggests that pregabalin treatment may help improve subjective measures of sleep and fatigue that are frequently associated with increased morbidity in FM.
“Our observations help expand [the] understanding of how pregabalin acts to improve and deepen sleep in FM which, in turn, may aid better targeting of treatment when sleep problems are reported to physicians,” the authors concluded.
The study findings were limited by the abbreviated length of the study, which left open the possibility of developing long term tolerance to the observed effects on sleep observed with pregabalin. Additionally, the generalizability of these findings is limited by the inclusion of mostly white females in the original analysis group. The incident rate of adverse effects of pregabalin in specific patient groups would also have to be considered.