Pregabalin Rapidly Improves Sleep in Painful Diabetic Peripheral Neuropathy, Postherpetic Neuralgia
HONOLULU, HI—Patients with diabetic peripheral neuropathy (DPN) or postherpetic neuralgia (PHN) treated with pregabalin have rapid, significant, and sustained improvement in sleep, according to a posthoc analysis of 16 placebo-controlled trials of pregabalin in 4,527 patients reported during the American Pain Society's 31st Annual Scientific Meeting.
This improvement usually occurs within the first three days of treatment with pregabalin, noted Bruce Parsons, MD, PhD, Senior Medical Director, Pfizer Inc, New York, NY, and colleagues, in reporting the first analysis to investigate pregabalin-mediated time-to-onset for improvement of pain-related sleep disturbance in patients with DPN or PHN.
“Patients with DPN and PHN frequently experience debilitating sleep disturbances,” they explained. “A reciprocal relationship has been suggested to exist between pain and sleep, with pain interfering with sleep and sleep disturbance increasing pain sensitivity.”
The investigators analyzed time to improvement in sleep, as measured by a reduction in sleep interference scores, in 3,056 patients with DPN and 1,471 with PHN enrolled in 30 pregabalin treatment arms that included 75-, 150-, 300- or 600mg/day for DPN and 150-, 300-, or 600mg/day for PHN. The majority of the doses were fixed; 4 were flexible (1 DPN, 1 PHN, and 2 DPN + PHN). All of the trials had sleep as a secondary end point.
In the DPN studies, median age was 60.0 years in both the placebo and pregabalin arms; 55.1% of the patients were male in the placebo arm vs. 55.9% in the pregabalin arm. In the PHN studies, median age was 71.5 years in the placebo arm and 72.0 years in the pregabalin arm; 51.% vs. 48.6% were male, respectively.
Daily sleep interference scores were based on an 11-point numeric rating scale and were analyzed using analysis of covariance in the intention-to-treat populations. The time-to-onset for reduction in sleep interference scores was calculated for all pregabalin treatment arms that demonstrated a statistically significant reduction in sleep interference scores at endpoint vs. placebo. Time-to-onset was defined as the first day sleep interference scores for that particular day, and the following day, were significantly lower when compared with placebo.
In the 16 trials, 24 of 30 (80%) of the pregabalin treatment arms achieved a significant reduction in sleep interference scores vs. placebo at end point, they found. When the 24 treatment arms were analyzed for time-to-onset for improvement in sleep interference scores, 22 of 24 (91.7%) treatment arms had a time-to-onset within the first three days of treatment; 20 of 24 (83.3%) within two days; and 16 of 24 (66.7%) of one day.
“One treatment arm did not achieve a significant improvement in sleep interference within the 14-day analysis period,” Dr. Parsons noted. Across the remaining 23 treatment arms, the mean (standard deviation) time-to-onset was 1.67 (1.34) days.