Adverse events associated with the use of direct-acting oral anticoagulants in clinical practice: beyond bleeding complications

Non-vitamin K oral anticoagulants, also known as direct oral anticoagulants (DOACs), have entered the market in 2008 with the expected breakthrough potential of circumventing limitations related to treatment with vitamin K antagonists (eg, warfarin) by virtue of their pharmacological properties. Although data derived from premarketing randomized clinical trials have largely demonstrated the clinical benefit of DOACs, especially in terms of reduced risk of intracranial bleeding, it is important to monitor the safety in the postmarketing phase, which better reflects real-world patients with comorbidities and polypharmacotherapy, in order to assess the actual risk-benefit profile. In this critical review, we aimed to evaluate the evidence on the latest debated safety issues. In the first section, we will discuss: 1) the need for pharmacovigilance (ie, the science and activities relating to the detection, assessment, understanding, and prevention of adverse effects or any other drug-related problems in the real-world setting), and 2) the importance of properly interpreting postmarketing data to avoid unnecessary alarm. In the second section, emerging and debated safety issues potentially associated with the use of DOACs in the postmarketing setting will be assessed: 1) the potential coronary risk (which emerged during the preapproval period); 2) the occurrence of liver injury (a risk undetected in clinical trials and highlighted by case reports or series); and 3) the potential for renal damage (a still unclear safety issue). It is anticipated that hepatic and renal issues still require dedicated postauthorization safety studies to ultimately assess causality.