Among People Who Inject Drugs, Benzodiazepine Use Is Associated with Hepatitis C Seroconversion

People who inject drugs (PWID) are at risk for hepatitis C (HCV) seroconversion. Benzodiazepines are commonly used medications that have been linked with risky behaviors. Researchers used data from 2 prospective cohorts in Vancouver, Canada to examine the association between benzodiazepine use and HCV seroconversion.

• Of 440 participants who were HCV antibody-negative at baseline, 158 (36%) reported benzodiazepine use (medical and/or non-medical) on at least 1 occasion during semiannual follow up.
• People with benzodiazepine use tended to be younger and were less likely to be homeless, more likely to inject heroin at least daily, and more likely to practice unsafe sex.
• A total of 142 HCV seroconversion events occurred in the cohorts, at a rate of 7.6 per 100 person-years.
• In bivariate analyses, benzodiazepine use was associated with HCV seroconversion (rate ratio [RR], 3.4), as were homelessness (RR, 1.7), at least daily heroin injection (RR, 3.5), at least daily cocaine injection (RR, 4.0), unsafe sex (RR, 1.6) and sex work involvement (RR, 3.4). In an adjusted model, benzodiazepine use remained independently associated with HCV seroconversion (RR, 1.7).

Comments:

The fact that benzodiazepine use was associated with HCV seroconversion may be due to the effects of these medications on cognition and judgment, or it may be a marker for other risk factors. Adjusting for some risk factors attenuated the association, but there may be other factors, particularly psychiatric disorders, that were not measured and may account for some or all of the association.

Darius A. Rastegar, MD

Reference:

Bach P, Walton G, Hayashi K, et al. Benzodiazepine use and hepatitis C seroconversion in a cohort of persons who inject drugs. Am J Pub Health. 2016:106(6):1067–1072.