Effect of substance abuse on ART pharmacokinetics

This study looked at a group of 275 patients, 47% of whom were active users of at least one substance (heroin 2%; cocaine 7%; marijuana 13%; tobacco 43%; alcohol 22%; prescription opioids 14%).

It was found that a significantly higher proportion of substance users had antiretroviral trough concentrations below the therapeutic range (23% vs 9%, p=0.048). The proportion of patients with an unfavourable treatment outcome (HIV RNA >75 copies/ml) was significantly higher in the substance user group than in the non-user group (40% vs 28%, p=0.044). However, when adjusted for race, substance abuse was no longer associated with virological response.

Ma Q, et al. Comparison of ART pharmacokinetics and clinical monitoring parameters in HIV-infected patients with and without substance abuse. 16th CROI, Montreal, 2009. Abstract 698.
http://www.retroconference.org/2009/Abstracts/35802.htm