Bupropion for the treatment of methamphetamine dependence in non-daily users: a randomized, double-blind, placebo-controlled trial

Abstract

Aim: Bupropion was tested for efficacy to achieve methamphetamine (MA) abstinence in dependent, non-daily users.

Methods: A randomized, double-blind, placebo-controlled trial, with 12-week treatment and 4-week follow-up, was conducted with 204 treatment-seeking participants having MA dependence per DSM-IV, who used MA on a less-than-daily basis. 104 were randomized to matched placebo and 100 to bupropion, sustained-release 150mg, twice daily. Participants were seen three times weekly to obtain urine for MA and bupropion assays, study assessments, and thrice weekly, 90-min, group psychotherapy. There was no biomarker for placebo adherence. The primary outcome was achievement of abstinence throughout the last two weeks of treatment; 'success' requiring at least two urine samples during each of Weeks 11 and 12, and all samples MA-negative (<300ng/mL).

Results: Bupropion and placebo groups did not differ significantly in the percentage achieving abstinence for the last 2 weeks of treatment (chi-square, p=0.32). Subgroup analysis of participants with lower baseline MA use (≤18 of last 30 days before consent) also revealed no difference in success between groups (p=0.73). Medication adherence per protocol (detectable bupropion, >5ng/mL, in ≥50% of urine samples from Study Weeks 1-10 and ≥66% of urine samples from Weeks 11 to 12) was achieved by 47% of participants taking bupropion.

Conclusions: These data indicate that bupropion did not increase abstinence in dependent participants who were using MA less-than-daily. Medication non-adherence was a limitation in this trial. Psychosocial therapy remains the mainstay of treatment for MA dependence. Further research on subgroups who may respond to bupropion may be warranted.

Keywords: Bupropion; Drug therapy; Medication adherence; Methamphetamine; Patient acuity; Substance-related disorders.

Fig. 1

Flow diagram of participants through the study of bupropion for methamphetamine (MA) dependence in less-than-daily users.

Fig. 2

Efficacy of bupropion for continuous abstinence from methamphetamine (by ≥ 2 urine samples per week), during the last number of weeks of treatment. Bupropion N=100, placebo N=104. (°p-value for primary outcome, Weeks 11 and 12, °°p-values for secondary outcomes, longer durations of terminal abstinence. χ² = chi-square, FE = Fisher’s Exact.)