Performance Characteristics of DOAC Dipstick in Determining Direct Oral Anticoagulants in Urine
Research article published in Clinical and applied thrombosis/hemostasis : official journal of the International Academy of Clinical and Applied Thrombosis/Hemostasis (2021)
Abstract
Testing for direct oral anticoagulants (DOACs) in patient urine may facilitate medical treatment decisions. The aim of this study was to investigate interobserver variability by 2 independent observers compared to laboratory staff in the visual interpretation of factor Xa (DXI) and thrombin inhibitors (DTI) using the DOAC Dipstick test. We also examined whether test pads reacted to other anticoagulants and abnormal urine colors. The colors of the DOAC Dipstick direct factor Xa inhibitor and thrombin inhibitor pads were interpreted with 100% accuracy (95% confidence interval 0.862 to 1.000) for urine samples from persons treated with apixaban (n = 26), rivaroxaban (n = 24), and dabigatran (n = 29) and without anticoagulant therapy (n = 29). The factor Xa and thrombin inhibitor pads did not interact with heparin, nadroparin, fondaparinux, or coumadin. One µg/mL r-Hirudin and 6 µg/mL argatroban interacted with the DTI pad; however, this is unlikely to cause clinical problems because dabigatran is unlikely to be administered together with r-Hirudin and argatroban in clinical circumstances. Abnormal urine color was reliably detected by the urine color pad, so can prevent false interpretation of the DOAC Dipstick pad colors. In conclusion, we have demonstrated that interobserver variability when interpreting the DOAC Dipstick test strip is low and that factor Xa and thrombin inhibitor pads do not react to other anticoagulants such as heparins and coumadin. R-Hirudin and argatroban can be detected by the thrombin inhibitor pad and abnormal urine colors can be detected by the urine color pad to prevent false interpretation of the results in patient urine samples.
Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.
Summary
Testing for direct oral anticoagulants (DOACs) in patient urine may facilitate medical treatment decisions.
Why This Matters for Hirudotherapy
This method-validation study tested the DOAC Dipstick urine assay and found its factor Xa and thrombin inhibitor pads identified apixaban, rivaroxaban and dabigatran (versus no anticoagulant) with 100% accuracy and low interobserver variability, did not react to heparins, fondaparinux or coumadin, but notably showed the thrombin inhibitor pad detected r-hirudin (1 microgram/mL) and argatroban. The hirudotherapy-relevant detail is that recombinant hirudin, the flagship leech-derived direct thrombin inhibitor, cross-reacts with the assay's thrombin-inhibitor pad, a useful point for clinicians and for the leech-secretome anticoagulant narrative. The caveat is that this is an analytical/diagnostic performance study of a urine test, not a clinical trial of hirudin or hirudotherapy; the authors note the r-hirudin/argatroban cross-reactivity is unlikely to cause clinical problems since these agents would not be co-administered with dabigatran, and the study evaluates test interpretation, not patient outcomes.
Citation
Performance Characteristics of DOAC Dipstick in Determining Direct Oral Anticoagulants in Urine
Harenberg J et al. · Clinical and applied thrombosis/hemostasis : official journal of the International Academy of Clinical and Applied Thrombosis/Hemostasis, 2021
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