Aims: Topiramate has shown efficacy at facilitating abstinence from alcohol and cocaine abuse. This double-blind, placebo-controlled out-patient trial tested topiramate for treating methamphetamine addiction.
Design: Participants (n = 140) were randomized to receive topiramate or placebo (13 weeks) in escalating doses from 25 mg/day [DOSAGE ERROR CORRECTED] to the target maintenance of 200 mg/day in weeks 6-12 (tapered in week 13). Medication was combined with weekly brief behavioral compliance enhancement treatment.
Setting: The trial was conducted at eight medical centers in the United States.
Participants: One hundred and forty methamphetamine-dependent adults took part in the trial.
Measurements: The primary outcome was abstinence from methamphetamine during weeks 6-12. Secondary outcomes included use reduction versus baseline, as well as psychosocial variables.
Findings: In the intent-to-treat analysis, topiramate did not increase abstinence from methamphetamine during weeks 6-12. For secondary outcomes, topiramate reduced weekly median urine methamphetamine levels and observer-rated severity of dependence scores significantly. Subjects with negative urine before randomization (n = 26) had significantly greater abstinence on topiramate versus placebo during study weeks 6-12. Topiramate was safe and well tolerated.
Conclusions: Topiramate does not appear to promote abstinence in methamphetamine users but can reduce the amount taken and reduce relapse rates in those who are already abstinent.
Trial registration: ClinicalTrials.gov NCT00345371.
© 2011 The Authors, Addiction © 2011 Society for the Study of Addiction.