Efficacy of pregabalin in the treatment of postherpetic neuralgia: a meta-analysis of randomized controlled trials

We aimed to summarize the efficacy of pregabalin in the treatment of postherpetic neuralgia (PHN) in pain reduction, sleep improvement and overall improvement of the patients in published studies. A literature search for randomized clinical trials (RCTs) investigating the efficacy of pregabalin for PHN was carried out in PubMed, EMBASE and the Cochrane database. For each trial met the inclusion criteria, study design, treatment comparators, dosage and duration, patient demographics and efficacy outcomes were extracted. The primary end point was treatment efficacy outcomes and the secondary end points included endpoint mean sleep interference score, percentage of 30% or 50% pain responders, and Patient Global Impression of Change (PGIC). A total of 5 RCTs with 9 different dosing groups involving 811 patients in the pregabalin group and 814 patients in the control group were included. The pooled SMD of mean pain score reductions was -0.651 (95% CI, -0.866, -0.435, P<0.001) in the pregabalin group compared with the placebo group. Higher dosing regimens resulted in greater reduction in pain score within a certain study but were not consistent among studies. Higher rate of patients with more than 30% and 50% pain score reduction in the pregabalin group vs. the placebo group. Significant benefits in mean sleep interference score and PGIC were observed in the pregabalin group vs. the control group. Higher dosing regimens yielded more improvement within each study but were not consistent among different studies. Pregabalin is effective in reducing the mean pain score and sleep interference score, increasing the percentage of 30% and 50% pain responders in comparison with placebo. Future studies are warranted to elucidate the effect of different dosing regimens on the treatment outcome.