Balancing the Interactions: Assessing Antiplatelet and Antiretroviral Therapy Drug-Drug Interactions in People Living with HIV.

The clinical effect of drug-drug interactions (DDIs) between antiplatelets and antiretrovirals (ART) on bleeding, thrombosis, and other major adverse cardiovascular events (MACE) is unknown. The objective of this retrospective study was to assess the incidence of DDI at P2Y12 inhibitor (P2Y12inh) initiation and the effect of DDI on patient outcomes. Adult people living with human immunodeficiency virus (PLWH; HIV) receiving ART newly initiated on an oral P2Y12inh were included. The primary outcome was the incidence of DDI between ART and P2Y12inh at P2Y12inh initiation. Secondary outcomes included bleeding events, MACE, and switches in P2Y12inh. There were 149 PLWH included, of these, 119 (80%) were initiated on clopidogrel, 23 (15%) on ticagrelor, and 7 (5%) on prasugrel. 93 PLWH (60%) had a DDI at time of P2Y12inh initiation, with highest incidence in the clopidogrel group (n=84, 71%), followed by ticagrelor (n=9, 39%) and none with prasugrel. Within 1 year, MACE occurred in 12 PLWH, with DDI present at the time of 4 events. There were 29 bleeding events occurring within 1 year, including 17 events with DDI at time of event. However, 88% of DDI in patients with bleeding events were expected to decrease the efficacy of P2Y12inh. Though we observed high incidence of DDI between P2Y12inh and ART in PLWH, MACE and bleeding events at 1 year did not correlate with DDI. It remains unknown if DDI presence at P2Y12inh initiation with ART causes clinical outcomes of concern, or if underlying platelet reactivity in PLWH is associated with these events.