The problem of underdosing with direct-acting oral anticoagulants in elderly patients with nonvalvular atrial fibrillation.

Unless contraindicated, anticoagulant therapy should be prescribed to elderly patients with atrial fibrillation. Direct-acting oral anticoagulants (DOACs) are superior to vitamin K antagonists for preventing stroke. This, together with their higher net clinical benefit, makes DOACs the treatment of choice in this population. However, due to the concerns about bleeding and the need for dose adjustment based on clinical variables, underdosing of DOACs is common and the risk of stroke high. Drugs with more easily adjusted doses are likely associated with a lower risk of dosing errors and, therefore, a greater protective effect. Correct dosing can ensure a maximal net benefit of DOACs in elderly patients with atrial fibrillation.