Brief Report: Medication Sharing Is Rare Among African HIV-1 Serodiscordant Couples Enrolled in an Efficacy Trial of Oral Pre-exposure Prophylaxis (PrEP) for HIV-1 Prevention.

Sharing of pre-exposure prophylaxis (PrEP) medications is a concern for PrEP implementation. For HIV-1 serodiscordant couples, sharing may undermine the HIV-1 prevention benefit and also cause antiretroviral resistance if taken by HIV-1 infected partners. Within a PrEP efficacy trial among HIV-1 serodiscordant couples, we assessed the occurrence of PrEP sharing by self-report and plasma tenofovir concentrations in HIV-1 infected partners. PrEP sharing was self-reported at <0.01% of visits, and 0%-1.6% of randomly selected and 0% of purposively selected specimens from HIV-1 infected participants had detectable tenofovir concentrations (median: 66.5 ng/mL, range: 1.3-292 ng/mL). PrEP sharing within HIV-1 serodiscordant couples was extremely rare.