Factors affecting the dose of methadone among patients receiving methadone maintenance therapy in Taiwan

Methadone maintenance treatment (MMT) has been shown to be an effective therapeutic strategy for opioid users. This study aimed to investigate the predictive effect of clinically predominant sleep disturbance (CPSD) on the dose of methadone among opiate users receiving MMT during a follow-up period of 6 years in Taiwan.This retrospective study included 1,290 individuals with opioid dependence who visited our MMT clinic for the first time. Generalized estimating equations were used to analyze the effect of CPSD on the daily dose of methadone by controlling for the effects of demographic and MMT characteristics.A total of 469 (36.4%) participants were comorbid with CPSD. After controlling for the effects of demographic and MMT characteristics, the participants comorbid with CPSD had a higher dose of daily methadone than those without CPSD (estimate: 7.03, p .001). Furthermore, younger age (estimate: -1.22, p .001), older age at initial MMT (estimate: .44, p .001), lower educational level (estimate: -.90, p = .003) and lower attendance rates (estimate: -.14, p = .033) are significantly related to higher doses of daily methadone.Our study provided a naturalistic observation of the cohort for long period, along with a large sample size which could reflect clinical practice in the real world. We reported that a higher daily dose of methadone was significantly associated with CPSD after controlling for the effects of other factors. CPSD should be routinely surveyed among heroin users receiving MMT. (Am J Addict 2018;27:225-230).