Original ArticleEffects of Rivaroxaban on Platelet AggregationHernandez-Juarez, Jesus PhD; Espejo-Godinez, Hugo Guillermo MSc; Mancilla-Padilla, Rodrigo MD; Hernandez-Lopez, Jose Rubicel PhD; Moreno, Jose Antonio Alvarado PhD; Majluf-Cruz, Karim MSc; Moreno-Hernández, Manuel MSc; Isordia-Salas, Irma MD, PhD; Majluf-Cruz, Abraham MD, PhD, FACPAuthor Information Unidad de Investigacion Medica en Trombosis, Hemostasia y Aterogenesis, Instituto Mexicano del Seguro Social, Mexico City, Mexico. Reprints: Abraham Majluf-Cruz, MD, PhD, FACP, Unidad de Investigacion Medica en Trombosis, Hemostasia y Aterogenesis, Instituto Mexicano del Seguro Social, Apartado Postal 12-1100, Mexico City, 03100 Mexico (e-mail: firstname.lastname@example.org). The authors report no conflicts of interest. Received July 25, 2019 Accepted September 20, 2019 Journal of Cardiovascular Pharmacology: February 2020 - Volume 75 - Issue 2 - p 180-184 doi: 10.1097/FJC.0000000000000770 Buy Metrics Abstract Rivaroxaban is a direct oral anti-factor Xa anticoagulant. It has recently been suggested that rivaroxaban may affect platelet function in vitro; however, little is known about the clinical impact of this likely antiplatelet effect and whether this probable phenomenon is dose-dependent. Our aim was to determine whether rivaroxaban at 4 different doses inhibits direct platelet aggregation. We included adult patients of both sexes and who were allocated to one of the following groups depending on the prescribed daily dose of rivaroxaban: 5, 10, 15, and 20 mg. In 80 patients (20 patients/group), the percentage of platelet aggregation was determined by means of platelet aggregometry tests before and after rivaroxaban use. Basal samples were obtained before starting rivaroxaban and 1 month after treatment, both 2 and 24 hours after the last dose of the drug (12 hours after in the case of rivaroxaban 5 mg). We used 5 platelet agonists: adenosine diphosphate, epinephrine, arachidonic acid, collagen, and thrombin. There were no significant changes in the percentage of platelet aggregation before and after rivaroxaban use independently of the dose administered and the agonist used. Our results have clearly shown that rivaroxaban, even at a high dose, does not directly affect platelet aggregation. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.