VANCOUVER, British Columbia – The introduction of opioid agonist therapy – also known as methadone maintenance treatment – has led to a dramatic decrease in HIV- and drug-related mortality in HIV-positive injection drug users, researchers report.
“Our study adds to a growing body of evidence showing that access to opioid agonist therapy has positive downstream effects on HIV-related outcomes,” lead author Bohdan Nosyk, PhD, from the BC Centre for Excellence in HIV/AIDS in Vancouver, British Columbia, Canada, said in statement.
“These findings strongly suggest that opioid therapy is an essential component to improving HIV outcomes among people who inject drugs,” he added.
The study results were presented here at the 8th International AIDS Society (IAS) Conference.
Dr Nosyk and his team used a linked population-level administrative database to identify a cohort of injection drug users living with HIV in British Columbia from 1996 to 2010.
Study participants had a history of opioid substitution, indicated by methadone or buprenorphine dispensation records, or a history of injection drug use before HIV infection, indicated in the HIV testing database.
Of the 1727 people in the study cohort, 28.5% died during the median follow-up of 5.1 years – 18.7% from drug-related causes, 55.8% from HIV-related causes, and 25.6% from other causes.
Standardized mortality ratios were significantly lower when participants were receiving opioid agonist therapy than when they were not (12.2 vs 30.0).
Opioid agonist therapy reduced the risk for all-cause mortality (adjusted hazard ratio [HR], 0.34; 95% confidence interval [CI], 0.23 – 0.49), as did highly active antiretroviral therapy (adjusted HR, 0.39; 95% CI, 0.31 – 0.48).
Together, opioid agonist therapy and antiretroviral therapy reduced all-cause mortality by 84%, Dr Nosyk reported.