4.4: Substance Use

Intravenous drug use is an important risk factor for transmission of HIV, accounting for 30% of new infections in Canada.¹ In addition, approximately 20% of people living with HIV in Canada use drugs.¹ Drug use and addiction can hasten the progression of HIV and its consequences, especially in the brain. Clinical research indicates that drug use and addiction may increase viral load, accelerate disease progression, and worsen AIDS-related mortality even among patients who follow ART regimens. In addition, people with substance use disorders are less likely adhere to ART, which worsens the course of their illness.²

There is an ongoing debate concerning the care of people who use drugs and whether harm reduction or abstinence is the best approach to handling the needs of these individuals. While abstinence requires the complete cessation of substance use, harm reduction advocates for the improvement of the health and safety of the person that is using substances by aiming to reduce the harms associated with it. Those in favour of the harm reduction model argue that abstinence is not a realistic goal for some people who use drugs and therefore should be not be used as a barrier to providing services. Community organizations working in HIV generally favour the harm reduction model. A full discussion of this topic and approaches to treatment can be found in Section 3_10 of the E-Module for Evidence-Informed HIV Rehabilitation (PDF) .

A substantial number of individuals who inject drugs and are living with HIV also have hepatitis C virus (HCV) coinfection.³ These individuals are at a significant higher risk for not receiving care or falling out of care.⁴ Impacts of the social determinants of health, specifically meeting basic needs for food, shelter and safety, undermine many individual’s in their attempt to adhere to HIV and HCV treatments, resulting in increased mortality and morbidity.³ For those receiving care, hepatotoxicity associated with ART can worsen the liver diseases associated with HCV.⁴ While HCV is now treatable/curable, successful treatment interventions for this population require an interdisciplinary approach, where available.⁵