Patterns of heroin, cocaine, and alcohol abuse during long-term methadone maintenance treatment.

Individuals' use of heroin, cocaine, and alcohol during long-term methadone maintenance treatment (MMT) was studied. Prospectively collected data from 103 heroin-addicted individuals who were consecutively admitted for MMT and remained 2 years in treatment were evaluated. The patients were assessed every 6 months with a standardized interview. Three longitudinal patterns of drug abuse were identified. A proportion of patients abstained fully from their particular drug use (26% from heroin, 39% from cocaine, and 19% from alcohol); a proportion (39%, 32%, and 47%, respectively) switched between periods of abuse and nonuse of these drugs; and chronic drug users (34%, 28%, and 33%, respectively) continued use, including periods of daily abuse throughout MMT. Different therapeutic interventions may be needed in patients with different longitudinal patterns of additional substance use during MMT.