The stem of our March 2022 Quick Question was, “How do you measure the anti-Xa DOACs rivaroxaban or apixaban?” The question drew 33 responses and here are the answer selections:
- We don’t measure the anti-Xa DOACs: 24% 
- Chromogenic anti-Xa using DOAC-specific calibrators and controls: 64% 
- Chromogenic anti-Xa using the unfractionated heparin curve: 3% 
- Chromogenic anti-Xa using the hybrid heparin curve: 9% 
- Partial thromboplastin time: 0
- Prothrombin time: 0
As indicated by Dr. Mayukh Sarfar, IL/Werfen offers an FDA-approved apixaban [Eliquis] calibrator and control set for use on their ACL Top analyzers. All other calibrator and control sets are employed in the US on a research use only [RUO] basis as they await approval. A handful of respondents estimate their DOAC activities from an unfractionated or hybrid heparin curve.