Dose-related efficacy of levomethadyl acetate for treatment of opioid dependence. A randomized clinical trial.

Abstract

To compare the clinical efficacy of different doses of levomethadyl acetate hydrochloride (known as LAAM) in the treatment of opioid dependence. A randomized controlled, double-blind, parallel group, 17-week study. Outpatient facilities at Johns Hopkins University Bayview Medical Center, Baltimore, Md. Opioid-dependent volunteers (N=180) applying to a treatment-research clinic. Thrice-weekly (Monday/Wednesday/Friday) oral LAAM dose conditions of 25/25/35 mg, 50/50/70 mg, and 100/100/140 mg and nonmandatory counseling. Retention in treatment, self-reported heroin use, and opioid-positive urine specimens. Retention was independent of subjects' sex and dose. Self-reported heroin use decreased in a dose-related manner. At final assessment, patients in the high-dose condition reported using heroin 2.5 of 30 days as compared with 4.1 or 6.3 days for patients in the medium-dose and low-dose conditions, respectively (high dose vs low dose, P<.05); urinalysis results were similarly dose related. Overall, 20 (34%) of 59 patients in the high-dose condition remained opioid-abstinent for 4 consecutive weeks, as compared with 8 (14%) of 59 in the medium-dose and 7 (11%) of 62 in the low-dose conditions (P<.01). Self-report and urinalysis data are consistent with a greater than 90% reduction in illicit opioid use by the high-dose group relative to pretreatment levels. Opioid substitution treatment with LAAM substantially reduces illicit opioid use. The clinical efficacy of LAAM is positively related to dose.