How to Manage an Anticoagulated Patient in Case of Drug-Drug Interaction?

Aims: The aim of this publication is to present the case of management of a patient on anticoagulation therapy with rivaroxoban in the context of a drug-drug interaction.
Presentation of Case: We report the case of a 73-year-old male diagnosed as having non-valvular atrial fibrillation treated with oral anticoagulants: dabigatran, acenocumarol and rivaroxaban in sequence.
Discussion: During concomitant administration of rivaroxaban and other commonly used agents, drug-drug interactions may occur. These can occur at the level of absorption, distribution, or clearance and are largely mediated by the P-gp transporter and the P450 (CYP) family of enzymes. One of the problems of direct-acting oral anticoagulants lies in the laboratory assays, as tests to measure drug levels are not well standardized and are not suitable for most centers. With rivaroxaban, PT is more sensitive than PTT; however, the results are dependent on the PT reagent used and other test with more specify have been introduced into the clinical practice.
Conclusion: It is pivotal that all clinicians who are treating patients with direct-acting oral anticoagulants become aware of relevant drug-drug interactions, as well as of the current limited possibilities to assess the level of anticoagulation.