Measuring Direct Oral Anticoagulant (DOAC) Levels: Applications, Limitations, and Future Directions

INTRODUCTION: There are important challenges with the measurement and interpretation of direct oral anticoagulant (DOAC) anticoagulant effect including a lack of therapeutic ranges, inaccuracy of routinely available coagulation assays, lack of established thresholds for clinically significant effect, and uncertainty about how to apply the results to patient care. OBJECTIVE: In this narrative review, we provide a practical approach to DOAC measurement in clinical practice. METHODS: By summarizing the literature and using illustrative cases, we highlight key principles of commonly available tests, outline potential indications for measuring DOAC drug levels, and provide guidance on interpreting results to inform management decisions. CONCLUSION: While DOACs do not require routine monitoring of anticoagulant effect, assessment of plasma DOAC concentration may be helpful in select emergency and non-emergency clinical scenarios.