The long-term outcomes of drug use by methadone maintenance patients.

The aim of the study is to predict long-term outcomes of methadone maintenance (MM), other than continued heroin use, on the basis of drug use occurring early in MM treatment. In previous research, the weak association of initial drug use during MM with measures of rehabilitation status may be due to the use of measures that do not differentiate trends in different types of drug use. In the present study, 222 patients who completed 6 months of MM were assessed at program intake, evaluated for opiates and cocaine in the first 6 months of treatment, and given a follow-up assessment 2 years after treatment entry. The intake status of the patients was assessed using the Addiction Severity Index. Opiate and cocaine use during the first 6 months of MM was assessed by urine toxicology. Outcomes were assessed using a structured interview and official criminal records at follow-up. Cluster analysis of urine toxicologies during treatment identified 3 trajectory classes of MM patients: (A) variably high levels of opiate use, but consistently low cocaine use; (B) low and diminishing opiate and cocaine use; and (C) consistently high cocaine use, with diminishing opiate use. In an 18-month period, after these trends were observed, Cluster C had significantly more criminal charges than Cluster B had (3 times as many), but not significantly more than those of Cluster A. Clusters A and B did not differ significantly in criminal charges. Regardless of cluster membership, subjects with increasing levels of cocaine use in the first 6 months of MM had more hospitalizations for drug and alcohol problems during the follow-up period than subjects without increasing levels of cocaine use had. The results provide evidence of negative sequelae of cocaine use during MM that underscore the importance of clinical efforts to reduce levels of cocaine and other nonopiate drug use by MM patients.