Abstract
Background: Vonoprazan is a potassium-competitive acid blocker increasingly used in Japan to prevent upper gastrointestinal bleeding in patients undergoing dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI). Cytochrome P450 (CYP) 3A4 is involved in the primary metabolism of both vonoprazan and prasugrel. This raises concern about the possibility of a CYP3A4-mediated drug-drug interaction between vonoprazan and prasugrel that may lead to attenuation of prasugrel's antiplatelet effect. Methods and Results: We evaluated 88 PCI patients who were taking either vonoprazan (n=45) or proton pump inhibitors (PPIs; n=43) in combination with DAPT (aspirin and prasugrel). Platelet reactivity on prasugrel was assessed using the VerifyNow P2Y(12) assay. The primary endpoint was comparison of P2Y(12) reaction units (PRU) between patients on vonoprazan and PPIs. PRU >208 and <85 were defined as high (HPR) and low (LPR) on-treatment platelet reactivity for prasugrel. PRU was comparable between patients receiving vonoprazan and PPIs (169±52 vs. 179±61, respectively; P=0.75). There were no significant differences between the vonoprazan and PPI groups in the prevalence of HPR (22% vs. 37%, respectively; P=0.16) and LPR (4 vs. 7%, respectively; P=0.48). The results were consistent regardless of the type of clinical presentation and DAPT duration. Conclusions: PRU under DAPT with aspirin plus prasugrel in patients receiving vonoprazan was not significantly different from that in patients receiving PPIs after PCI in routine clinical practice.