Changes in alcohol use during hepatitis C treatment in persons who inject drugs.

People who inject drugs (PWID) are a vulnerable population at high risk for acquiring hepatitis C virus (HCV) and frequently suffer from comorbid alcohol use. This study examines the characteristics and correlates of alcohol use among study participants, the association between alcohol consumption and sustained virologic response (SVR) in patients receiving HCV treatment, changes in drinking behaviours during HCV treatment and associations of drinking over time with specific models of HCV treatment. Participants were 150 PWID with HCV who were receiving opioid agonist therapy (OAT) and enrolled in a randomized clinical trial exploring the effectiveness of three models of care for HCV treatment. The addiction severity index was the primary measure of alcohol consumption. Days of alcohol intake were evaluated longitudinally and across three treatment groups. At baseline, 31% (47/150) reported having at least one drink in the last 30 days including 24% (36/150) who reported drinking to intoxication in the last 30 days. There was no difference in SVR rates between groups. There was a significant decrease in overall days of drinking from baseline (7.78 ± 7.86) to follow-up at Week 24 (5.78 ± 8.83) (p = 0.041), but there were no significant changes among those who drank to intoxication; modified directly observed therapy (mDOT) was the only group with a significant decline in days of alcohol consumption (p = 0.041). In this cohort of PWID on OAT, baseline alcohol consumption did not affect SVR rates. HCV treatment was overall associated with decreased alcohol consumption. In particular, mDOT was associated with decreased alcohol consumption. Given the additive effect of alcohol and HCV on the development of cirrhosis, studies should be done to investigate the complimentary effects of the mDOT model of care on alcohol cessation.