IAC: Injection Drug Use No Bar to HIV Therapy

By Michael Smith
MEXICO CITY, 04 aug 2008-- Injection drug use doesn't change the chance of survival among HIV-positive patients starting highly active antiretroviral therapy (HAART), researchers said here. In a 10-year observational study, injection drug users had death rates that were similar to other HIV-positive patients starting HAART, according to Julio Montaner, M.D., of the University of British Columbia in Vancouver, and colleagues. The finding should quash the common view that people who use injection drugs are inherently unable to benefit from therapy because of their unstable life style, said Dr. Montaner, who is also president-elect of the International AIDS Society.
The study appears in the Aug. 6 issue of the Journal of the American Medical Association and was released here in conjunction with the 17th International AIDS Conference.
The study implies that extending HAART to injection drug users "should be a priority, given that barriers remain" to access, Dr. Montaner said, adding that the Joint United Nations Program on HIV/AIDS has found that -outside of sub-Saharan Africa - a third of all HIV infections are among injection drug users.
The study covered all antiretroviral-naïve residents of the Canadian province of British Columbia who started HAART between Aug. 1, 1996, and June 30, 2006.
The 3,116 patients, with a median age of 39.4, included 915 injection drug users and 579 females. The median duration of follow-up was 5.3 years for the drug users and 4.3 years for others.
Dr. Montaner said previous studies showing worse outcomes for injection drug users on HAART were performed in areas where access to treatment was not free.
He noted that HIV/AIDS care is free in British Columbia, removing a major barrier to care.
A province-wide vital statistics bureau allowed all patients to be followed until death or the end of the study and their causes of death analyzed.
The study found that 622 study participants died during the study period, for a crude mortality rate of 20.0%. Of those, 232 were injection drug users.
The cumulative all-cause mortality rate was similar between the groups -- 26.5% for the drug users and 21.6% for the others - and in a multivariate time-updated Cox regression, the hazard ratio of mortality was also similar (1.09 with a 95% confidence interval from 0.92 to 1.29).
In sub-analyses, Dr. Montaner and colleagues excluded deaths unlikely to be related to HIV, including such things as accidental poisonings, trauma, and suicides.
The drugs users were significantly more likely (P=0.003) than non-users to die of such causes - they accounted for 21.1% of such deaths compared with 9.7%.
However, when accidental deaths were excluded, the death rates again were not statistically different -- 22.4% for the drug users compared 19.1% for the others.
The bottom line, Dr. Montaner said, is that "once barriers are removed, injection drug users can successfully enter treatment."
The study was limited by only having baseline data on injection drug use. So any effect of ongoing drug use could not be ascertained.
The study also only enrolled injection drug users who had HAART prescribed. The authors acknowledged that the overall rate of death might be higher if all injection drug users were counted. Nonetheless, the study demonstrated that injection drug users given HAART had a similar mortality rate to those who did not inject drugs.
The study was supported by the Canadian Institutes of Health Research and the Michael Smith Foundation for Health Research. Dr. Montaner receiving educational grants from and serving as an ad hoc advisor to or speaking at various events sponsored by Abbott Laboratories, Agouron Pharmaceuticals Inc., Boehringer Ingelheim Pharmaceuticals Inc., Borean Pharma AS, Bristol-Myers Squibb, DuPont Pharma, Gilead Sciences, GlaxoSmithKline, Hoffmann-La Roche, Immune Response Corp., Incyte, Janssen-Ortho Inc., Kucera Pharmaceutical Company, Merck Frosst Laboratories, Pfizer Canada Inc., Sanofi Pasteur, Shire Biochem Inc., Tibotec Pharmaceuticals Ltd., and Trimeris Inc.
Primary source: Journal of the American Medical AssociationSource reference:Wood E at al. "Highly Active Antiretroviral Therapy and Survival in HIV-Infected Injection Drug Users." JAMA. 2008;300(5):550-554.