Antiretroviral Boosting Agent Cobicistat Increases the Pharmacokinetic Exposure and Anticoagulant Effect of Dabigatran in HIV-Negative Healthy Volunteers

Drug interactions between antiretroviral therapy and anticoagulant medications are of particular concern given that ≈50% of the current HIV population is >50 years of age. Moreover, HIV infection is characterized by a hypercoaguable state and premature immunologic aging, in which thromboembolic events may be as much as 10 times more prevalent than in the general population across all age spectra.1 Dabigatran was the first direct oral anticoagulant approved by the US Food & Drug Administration and is the only direct oral anticoagulant with a US Food & Drug Administration -approved specific reversal agent, idarucizumab. Unlike warfarin and many other direct oral anticoagulants, dabigatran is not a substrate, inhibitor, or inducer of cytochrome P450 metabolic enzymes. However, dabigatran is a substrate of Permeability-glycoprotein (P-gp) and renal multidrug and toxin extrusion-1 transporters. Cobicistat is a US Food & Drug Administration -approved antiretroviral-boosting agent that is coformulated with numerous fixed-dose combination antiretroviral products because of its inhibitory effects on cytochrome P450 3A4. Currently, ≈40% of all treatment-naive patients with HIV in the United States are initiated on a cobicistat-boosted antiretroviral regimen. In addition to cytochrome P450 3A4, cobicistat is also an inhibitor of both P-gp and multidrug and toxin extrusion-1 transporters.2 Thus, this study aimed to determine whether the …