Pregabalin for Neuropathic Pain: Not More Effective Than Placebo

A randomized, controlled, double-blind study presented at the International AIDS Society conference in Mexico City compared the efficacy of pregabalin (Lyrica) with placebo for HIV-infected patients with painful peripheral neuropathy. A total of 151 patients were treated with pregabalin (150-600 mg total daily dosage, depending on tolerance; an average of 386 mg/day), and an equal number received placebo. The groups were well matched at baseline, and had comparable mean pain scores and duration of symptoms. At 14 weeks, both groups had improvements in pain, with a mean decrease in pain score of about 3 points in the pregabalin group and about 2.5 points in the placebo group. This difference was not statistically significant. About 40% of subjects in each group gained ≥50% decrease in their pain scores, with no significant difference between groups. Pregabalin in general was tolerated well, with reported adverse effects of somnolence, dizziness, euphoria, and peripheral edema.

Clinical Bottom Line

For patients with postherpetic neuralgia and diabetic neuropathy, pregabalin has significant benefit over placebo. In this study, among patients with HIV-related painful peripheral neuropathy, both the pregabalin and the placebo recipients experienced notable improvements in pain, but pregabalin was not more effective than placebo. The study investigators argued that the placebo response in this study was particularly robust, but were unable to explain that observation. The outcome is disappointing, as peripheral neuropathy brings substantial suffering to a high proportion of HIV-infected individuals.

References

Simpson DM, Murphy TK, Durso-De Cruz E, et al. A randomized, double-blind, placebo-controlled, multicenter trial of pregabalin vs placebo in the treatment of neuropathic pain associated with HIV neuropathy. In: Program and abstracts of the XVII International AIDS Conference; August 3-8, 2008; Mexico City. Abstract THAB0301.