Introduction: Levo-Alpha-Acetylmethadol (LAAM) is a synthetic opioid analgesic with μ-agonistic activity and a long duration of action. There are several, almost exclusively US American studies showing the efficacy of LAAM as a maintenance drug which has the advantage that it needs to be administered only three times a week. LAAM is currently not marketed in EU countries due to cardiac complications. We report on the first European multi-center, parallel group, flexible dose, open-label, randomized clinical trial comparing LAAM and methadone in patients with opioid dependence.

Methods: Eighty-four opioid addicts in ongoing maintenance treatment with stable methadone doses were treated with methadone under study conditions for 5 weeks (run-in phase), then randomly assigned to a methadone (n=41) or a LAAM (n=43) group. Study duration was 24 weeks after randomization. Objective measures (drug urine screenings, retention rate), subjective measures (symptoms of withdrawal and craving, report of substance use), and safety data were collected weekly. The main outcome criterion was the number of opiate-free urine samples per number of weeks of study participation.

Results: Non-inferiority was shown for LAAM compared to methadone. Both substances were well tolerated. There were no clinical cardiac complications in either group.

Discussion: Our study confirmed the results of previous investigations with LAAM as being efficacious and well tolerated in opioid dependence. A discussion to reconsider the availability of LAAM is recommended.