Injection drug use and HIV antiretroviral therapy discontinuation in a Canadian setting.

We investigated whether drug-related behaviors predicted antiretroviral therapy (ART) discontinuation among a cohort of injection drug users (IDU) in a Canadian setting. Cox regression analyses were used to investigate the impact of drug use patterns on rates of ART discontinuation among a sample of HIV-positive IDU in Vancouver, Canada between May 1996 and April 2008. In total, 408 HIV-positive IDU initiated ART during the study period, among whom 257 (63.0%) discontinued ART at least once. Rates of ART discontinuation were not significantly elevated among those who reported ongoing injection of heroin, cocaine, or other illicit drugs in comparison to those who reported not injecting drugs. However, public drug use was significantly predictive of ART discontinuation. Our findings may contribute to a reconsideration of the role of active drug use in determining retention in ART programs among IDU.