Multiple substance use among heroin-dependent patients before and during attendance at methadone maintenance treatment program, Yunnan, China.

BACKGROUND Multiple substance use is a common problem among heroin users. This study aims to describe patterns of multiple substance use one year before and during attendance at methadone maintenance treatment (MMT) programs and associated variables of continued heroin use in MMT clinics in Yunnan, China. METHODS The study was conducted among 168 heroin addicts who had received treatment for at least one year at two MMT clinics in Kunming city. A structured questionnaire, a medical record, and computer database were used to obtain history of substances use, significant clinical information, and treatment details, respectively. RESULTS Heroin, tobacco, and alcohol were the most commonly used substances both before and during MMT. After one year in MMT, use of heroin, alcohol, tramadol, and triazolam significantly decreased whereas use of ephedrine increased. Simultaneous substance use was halved but the decrease was not statistically significant. The proportion of injecting users was reduced from 61% to 43%. History of heroin use in the preceding 6 months during MMT increased the odds of continued heroin use (OR=5.8, 95% CI=[2.9-11.3]). An average 10mg higher methadone dose increment was associated with a reduced odds of heroin use by 10%. CONCLUSION MMT did not reduce the number of substances used, but the number of injecting heroin users after the first year of treatment decreased. Heroin use in the preceding 6 months during MMT treatment and lower methadone dose were associated with continued heroin use in MMT.