Daily Tenofovir Pre-Exposure Prophylaxis Reduces HIV Transmission among People with Injection Drug Use in Drug Treatment
Pre-exposure prophylaxis with tenofovir/emtricitabine combination or tenofovir alone reduces the incidence of HIV infection from sexual transmission by about half, as long as adherence is adequate. Researchers conducted a randomized, placebo-controlled trial of daily pre-exposure prophylaxis with tenofovir among 2413 people in Bangkok, Thailand who injected drugs in the past year. Study sites were 17 drug treatment clinics that offered a package of HIV prevention interventions and directly observed therapy. Participants chose to receive medication via daily directly observed therapy or monthly visits and could switch monthly.
- At the beginning of the study, 33% of the sample abused methamphetamine, 22% abused heroin, 23% abused midazolam, and 22% were receiving methadone maintenance treatment.
- At the beginning of the study, the placebo group reported more sexual intercourse in the prior 12 weeks among men who had sex with men (6% versus 4%) and sex with a casual partner (40% versus 36%).
- Mean follow-up time was 4 years. Mean adherence was 84% of days. Participants received directly observed therapy 87% of the study days.
- Forty-five percent of participants reported at least one incidence of injection drug use during follow-up.
- There were 17 HIV seroconversions (incidence of 0.35 per 100 person-years) in the tenofovir group and 35 (0.68 per 100 person-years) in the placebo group, a 49% reduction in HIV incidence. HIV incidence did not differ until 36 months of follow-up.
- Nausea, vomiting (8% versus 5%), and increase in ALT (53% versus 49%) were more common in the tenofovir group.