Randomized, placebo-controlled trial of baclofen and gabapentin for the treatment of methamphetamine dependence.

Abstract

To conduct a 16-week, randomized, placebo-controlled, double-blind trial of two GABAergic medications, baclofen (20 mg tid) and gabapentin (800 mg tid), for the treatment of methamphetamine dependence. Adults with methamphetamine dependence were randomized to one of three conditions for 16 weeks: baclofen (n = 25), gabapentin (n = 26) or placebo (n = 37). All participants attended clinic thrice weekly to receive study medication and psychosocial counseling, complete study assessments, and provide urine samples. No statistically significant main effects for baclofen or gabapentin in reducing methamphetamine use were observed using a generalized estimating equation (GEE). A significant treatment effect was found in post hoc analyses for baclofen, but not gabapentin, relative to placebo among participants who reported taking a higher percentage of study medication (significant treatment group and medication adherence interaction in GEE model of methamphetamine use). While gabapentin does not appear to be effective in treating methamphetamine dependence, baclofen may have a small treatment effect relative to placebo. Future studies evaluating the effectiveness of baclofen and other GABAergic agents for treatment of methamphetamine may be warranted.