Pharmacokinetic drug–drug interactions with direct anticoagulants in the management of cancer‐associated thrombosis

Drug–drug interactions (DDIs) are common in cancer management and complicate the choice of anticoagulation in cancer‐associated thrombosis. Cancer confers an increased risk of thrombotic events. Also, more bleeding events are observed in those who receive anticoagulation compared to those without cancer. In the treatment of cancer‐associated thrombosis, direct oral anticoagulants (DOACs) have been found to be at least as effective as low‐molecular weight heparins, which became the standard of care after several trials demonstrated superiority over vitamin K antagonists. Non‐inferiority compared to low‐molecular weight heparins has been shown for rivaroxaban, edoxaban and apixaban with a signal of fewer recurrent thrombotic events, albeit with an increase in bleeding events. Yet, potentially major pharmacokinetic drug–drug interactions have been identified as a reason to withhold DOACs and to rather choose an alternative. Practical guidance on what constitutes a major pharmacokinetic interaction and/or how to deal with these interactions in clinical practice is limited. Hence, here we have provided a framework to allow clinicians to better deal with pharmacokinetic drug–drug interactions between DOACs and cancer therapies in the management of cancer‐associated thrombosis. In this review we have discussed the current literature, how the pharmacokinetic profile links to the label information on DDI, and have provided a practical proposal, applied to a clinical case.