To the Editor Dr Powell1 advocated for individualized therapy for the new direct-acting oral anticoagulants (DOACs) based on defined therapeutic target ranges simulated from phase 3 trials.
The idea of therapeutic drug monitoring is derived from the monitoring of vitamin K antagonists (VKAs), which have a narrow therapeutic window. Because of the multiple interactions of VKAs, therapeutic drug monitoring is the only possible way to ensure patient safety.
Kreuzer J, Dugi K. Dosing Recommendations for New Oral Anticoagulants. JAMA. 2015;313(24):2496. doi:10.1001/jama.2015.5739