Abstract

Crystal methamphetamine injection predicts slower HIV RNA suppression among injection drug users

Presented by Nadia Fairbairn (Canada).

N. Fairbairn¹, T. Kerr^1,2, M.-J. Milloy¹, R. Zhang¹, J. Montaner^1,2, E. Wood<sup>1,2

1</sup>BC Centre for Excellence in HIV/AIDS, Vancouver, Canada, ²Department of Medicine, University of British Columbia, Vancouver, Canada

Background: Increasing crystal methamphetamine (CM) use worldwide poses a significant threat to HIV prevention and treatment strategies. CM has been linked to sexual and parenteral risk behaviours and increased likelihood of HIV seroconversion, as well as poor adherence to antiretroviral therapy. We examined the impact of CM injection on HIV RNA suppression among a prospective cohort of HIV-positive injection drug users (IDUs) initiating antiretroviral therapy.
Methods: We enrolled HIV-positive IDUs into a community-recruited prospective cohort study. We modeled factors associated with HIV RNA suppression using Cox regression to determine factors independently associated with viral load suppression.
Results: Between September 1996 and April 2008, 384 (54.2%) antiretroviral-naïve patients initiated highly active antiretroviral therapy (HAART) among whom 163 (42.5%) were women. Overall, 36 (9.4%) reported CM injection at any time during follow-up. A multivariate Cox regression analysis found CM injection to be negatively associated with viral load suppression (RH = 0.63 [95% CI: 0.40 - 0.98]; p = 0.039), even after adjustment for age, baseline CD4 cell count and viral load, heroin injection and cocaine injection.
Conclusions: This study is the first to our knowledge to demonstrate an association between CM use and HIV RNA suppression. These data contribute further evidence to the negative health outcomes associated with CM use among HIV-positive individuals. Our findings are most likely explained by the fact that the psychopharmacological effects of CM may undermine antiretroviral treatment adherence. Given the continued increases in CM consumption despite attempts to deter use, strategies to improve drug treatment, as well as improved HIV prevention and treatment adherence strategies for this high risk group require urgent implementation.