In Reply I agree with Drs Kreuzer and Dugi that DOACs are probably better drugs than warfarin for the reasons described. However, there is a strong probability that DOACs could be significantly more efficacious and safer for all patients. For drugs with narrow therapeutic indexes in which death can result from underdosing or overdosing, a more personalized dosing scheme seems worthy to evaluate.
My Viewpoint advocated re-analyzing the results of all phase 3 trials of DOACs to determine if individualized dosing to either a drug plasma concentration or pharmacodynamic biomarker end point associated with efficacy and safety is warranted. It would be impossible for me to advocate therapeutic drug monitoring now because an individualized dosing scheme has not been established. This work should be done.
Powell JR. Dosing Recommendations for New Oral Anticoagulants—Reply. JAMA. 2015;313(24):2496-2497. doi:10.1001/jama.2015.5754