Efficacy and safety of pregabalin in patients with neuropathic pain due to spinal cord injury: a pooled analysis

Abstract

Central neuropathic pain due to spinal cord injury (SCI) is often chronic and severe. Many pharmacologic treatments are limited by severe side effects, lack of efficacy, or lack of sufficient clinical data to support their use. Pregabalin is the only agent approved by the United States Food and Drug Administration for the treatment of SCI-related neuropathic pain. This approval was based on two large-scale, randomized, placebo-controlled trials of pregabalin, which comprise the largest published database of any pharmacologic compound for treatment of SCI-related neuropathic pain. Our analysis pools data from these two trials to explore the safety, tolerability, and efficacy of pregabalin in an expanded SCI population. A total of 174 patients received placebo and 182 received pregabalin. Patients rated pain severity from 0 = no pain to 10 = worst possible pain. Duration Adjusted Average Change in pain was significantly improved in patients receiving pregabalin compared to placebo (placebo adjusted change = -0.80; 95% CI = -1.09, -0.51; p<0.001). Mean change in pain from baseline to endpoint was also significantly improved compared to placebo (BOCF; p<0.001). The percentage of patients achieving ≥30% and ≥50% reductions in pain from baseline to endpoint was significantly greater in the pregabalin arm compared to placebo (placebo: 30 = 25.4%, 50 = 12.1%: pregabalin 30 = 44.2%, 50 = 26.4%) (LOCF; all p<0.05). Treatment-related adverse events (AEs), most commonly somnolence, dizziness, dry mouth, fatigue, edema, blurred vision, and constipation, occurred more frequently in patients treated with pregabalin compared to placebo. Patients receiving benzodiazepines concomitant to pregabalin had higher rates of somnolence than patients receiving pregabalin in the absence of benzodiazepines. Most AEs were mild-to-moderate in severity. Overall, our data highlight the safety and efficacy of pregabalin for the treatment of neuropathic pain due to SCI. Funded by Pfizer Inc.