OBJECTIVE: This study sought to detect CYP2B6 and OPRM1 variants and their genotypes, as major contributors to inter-variability in methadone responsiveness and methadone dose requirements.
METHODS: We carried out a prospective experimental one-phase pharmacogenetic study in four addiction clinics in Malaysia. Patients on stable methadone maintenance therapy were recruited. The prevalence of the CYP2B6 and OPRM1 polymorphisms was determined using a nested polymerase chain reaction (PCR), followed by genotyping. A two-step multiplex PCR method was developed to simultaneously detect the 26 SNPs in these two genes.
RESULTS: 120 males were recruited for this study. The patients were between 21and 59 years old, although the majority of the patients were in their 30s. C64T and G15631T in CYP2B6and G31A, G691C, and A118G in OPRM1 were found to be polymorphic, and the allelic frequencies of each were calculated. We further detected eight new haplotypes.
CONCLUSION: C64T and G15631T in CYP2B6and G31A, G691C, and A118G in OPRM1were found to be polymorphic. The new haplotypes may give a new insight on methadone clinics.
METHODS: We conducted an analysis of policy documents and over 60 h of participant observation in February 2016, which included focus groups with a convenience sample of 20 therapeutic community staff members, 110 prisoners across three male and one female prisons, and qualitative interviews with two former Clean Zone participants. Field notes containing verbatim quotes from participants were analyzed through iterative reading and discussion to understand how participants generally perceive the program, barriers to entry and retention, and implications for future treatment within prisons.
RESULTS: Our analyses discerned three themes: pride in the mission of the Clean Zone, idealism regarding addiction treatment outcomes against all odds, and the demonization of methadone.
CONCLUSION: Despite low enrollment and lack of an evidence base, the therapeutic community is buttressed by the strong support of the prison administration and its clients as an "ordered" alternative to what is seen as chaotic life outside of the Clean Zone. The lack of services for Clean Zone patients after release likely contributes to high rates of relapse to drug use. The Clean Zone would benefit from integration of stabilized methadone patients combined with a post-release program.
METHODS: This study prospectively evaluated mortality after prison release and whether methadone initiated before release increased survival after release in a sample of men with HIV and OUD (n = 291). We linked national death records to data from a controlled trial of prerelease methadone initiation conducted from 2010 to 2014 with men with HIV and OUD imprisoned in Malaysia. Vital statistics were collected through 2015. Allocation to prerelease methadone was by randomization (n = 64) and participant choice (n = 246). Cox proportional hazards models were used to estimate treatment effects of prerelease methadone on postrelease survival.
RESULTS: Overall, 62 deaths occurred over 872.5 person-years (PY) of postrelease follow-up, a crude mortality rate of 71.1 deaths per 1000 PY (95% confidence interval [CI] 54.5-89.4). Most deaths were of infectious etiology, mostly related to HIV. In a modified intention-to-treat analysis, the impact of prerelease methadone on postrelease mortality was consistent with a null effect in unadjusted (hazard ratio [HR] 1.3, 95% CI 0.6-3.1) and covariate-adjusted (HR 1.2, 95% CI 0.5-2.8) models. Predictors of mortality were educational level (HR 1.4, 95% CI 1.0-1.8), pre-incarceration alcohol use (HR 2.0, 95% CI 1.1-3.9), and lower CD4+ T-lymphocyte count (HR 0.8 per 100-cell/mL increase, 95% CI 0.7-1.0).
CONCLUSIONS: Postrelease mortality in this sample of men with HIV and OUD was extraordinarily high, and most deaths were likely of infectious etiology. No effect of prerelease methadone on postrelease mortality was observed, which may be due to study limitations or an epidemiological context in which inadequately treated HIV, and not inadequately treated OUD, is the main cause of death after prison release.
TRIAL REGISTRATION: NCT02396979. Retrospectively registered 24/03/2015.