Drug-drug interactions in anticoagulant therapy: a focus on oncology patients

INTRODUCTION: Patients with cancer are frequently exposed to polypharmacy, carrying a high risk of drug-drug interactions (DDIs). Given their substantial risk for thrombosis and atrial fibrillation, anticoagulants are commonly prescribed in this population. Anticoagulants can be associated with relevant pharmacokinetic and pharmacodynamic DDIs, yet their clinical significance remains undetermined. AREAS COVERED: A literature search of preclinical and clinical studies was performed to identify DDIs between anticoagulation and anticancer treatment, with an emphasis on pharmacokinetic and pharmacodynamic mechanisms. This narrative review summarizes the general principles of DDIs involving anticoagulation in patients with cancer. A comprehensive review of DDIs between anticoagulants and different classes of anticancer therapies is provided, including recent outcome studies evaluating their impact on mortality, clinically relevant bleeding, and thrombosis. EXPERT OPINION: Based on available data, we propose a practical approach to DDI assessment and clinical interpretation to support decision-making in patients with cancer requiring anticoagulation. This includes systematic screening for DDIs, tailoring anticoagulants during both initial and long-term treatment (primarily in the context of venous thromboembolism), providing patient counseling based on available evidence, and involving the pharmacy team in complex cases.