Abstract 11035: Specificity of Points of Care Tests for Urine From Patients on Therapy With Dabigatran, Rivaroxaban, and Apixaban
In specific and acute clinical situations it may be necessary to know if a direct oral anticoagulant (DOACs) is on board of a patient or not for medical management of the disease. DOACs are excreted rapidly between 25% and 80% by glomerular filtration into the urine. We have developed point of care (POC) methods to determine the presence or absence of dabigatran, rivaroxaban and apixaban in urine. Here we investigated the interaction other anticoagulants because they are also eliminated from the circulation by renal excretion.
Urine samples were obtained from patients on treatment with 110mg or 150mg bid dabigatran (n=15) (international patent application No. PCT/EP2012/002540), rivaroxaban 10mg od (n=15), and apixaban 5mg bid (n=6) (international patent PCT/WO2012/069139A1) and controls (n=6). Studies were accepted by the local ethical board and patients gave written informed consent. Urine samples of patients on dabigatran and controls were spiked with 0.0 and 1.0 IU/ml heparin, 0.0 and 1 μg/ml hirudin and argatroban. Urine samples of patients on rivaroxaban and apixaban or controls were spiked with similar concentrations of heparin, nadroparin and fondaparinux. Urine was incubated over 15 min in the POC tests and colour changed from negative to positive in the absence of DAOCs (Dabigatran: green for negative, blue for positive, rivaroxaban/apixaban: yellow for negative, no colour for positive). Colours were read by the naked eye and results are also given as optical density.
The POC tests for dabigatran and rivaroxaban/apixaban were positive in all patients on therapy and negative in controls. UFH, LMWH, fondaparinux and argatroban did not indicate any interaction in all experimental settings as determined by the colour read by the naked eye and by the optical density. Hirudin showed some interaction with the POC test for dabigatran.
The specificity of the POC assays for dabigatran, rivaroxaban and apixaban in urine is high except for hirudin. Concomitant therapy with dabigatran and hirudin is unlikely to occur in clinical practice. The assays are easy to perform, rapid, non-invasive and ca be performed by patients. Its place in medical decision making should be any acute illness as well as control of compliance.
- © 2013 by American Heart Association, Inc.