Oral Naltrexone Decreases Use and Extends Time to Relapse in Amphetamine Dependent Patients
Currently, no medications are FDA-approved to treat amphetamine dependence. Naltrexone, an opioid antagonist, has shown efficacy in reducing relapse among subjects with opioid or alcohol dependence. Investigators from Sweden, where amphetamine is the most commonly abused stimulant, conducted a 12-week randomized double-blind controlled trial among 80 amphetamine-dependent subjects to determine whether daily oral naltrexone decreased amphetamine use compared with placebo. Fifty-five patients completed the trial. Two weeks of abstinence from amphetamine were required to enter the trial, and subjects with dependence on alcohol or other drugs were excluded. Both groups attended once-weekly relapse prevention counseling and underwent twice-weekly urine toxicology testing. Missing urine tests were considered positive.
- In intent-to-treat analysis, 65% of urine tests in the naltrexone group and 48% in the placebo group were negative for amphetamines (p<0.05).
- The mean number of urine tests prior to first relapse was 13 in the naltrexone group and 6 in the placebo group.
In this study, oral naltrexone reduced amphetamine use and extended time to relapse in recently abstinent amphetamine-dependent patients. Clinical trials of naltrexone for cocaine dependence have not shown this efficacy, and its effectiveness for methamphetamine dependence is not known. Studies in larger and more diverse populations, especially those who have not attained abstinence prior to initiating the medication, are needed to confirm naltrexone’s effectiveness for amphetamine and other stimulant dependence.Alexander Y. Walley, MD, MSc