Is it reasonable to use a lower DOAC dose in some patients with VTE? NO.

The international guidelines recommend the use of direct oral anticoagulants (DOACs) over vitamin K antagonists for anticoagulation long-term therapy in patients diagnosed with venous thromboembolism (VTE), and for stroke prevention in patients with non-valvular atrial fibrillation (AF). Efficacy and safety of DOACS have been extensively evaluated in large phase III trials. According to the product label, dose reductions of DOACs are recommended for patients with AF and renal impairment, low body weight and concomitant use of interfering medications. Except for Edoxaban, dose reductions of DOACs are not recommended in patients with VTE based on the same indications for AF patients. The aim of this article is to discuss the indication of a lower DOAC dose in some patients with VTE. Observational studies and randomized control trials (RCTs) show that patients with AF are usually older, more often have chronic diseases, and more often are treated with several concomitant medications, potentially increasing their haemorrhagic risk. Furthermore, many VTE patients need a shorter period of anticoagulation therapy than AF patients. In real-life studies, VTE patients treated with inappropriate DOAC doses present a higher rate of VTE recurrence, and the same risk of bleeding compared to those treated with the correct dose. In light of this evidence, the use of lower DOAC dose in patients with VTE does not appear reasonable and may be potentially dangerous.