Measurement of Dabigatran in Serum and Urine and As Point of Care Method in Urine,

Abstract 3352

The oral direct thrombin inhibitor dabigatran prevents development of arterial and venous thromboembolism. Dabigatran is determined in plasma by coagulation and chromogenic methods. Renal excretion plays an important role in the metabolism. We aimed to determine dabigatran in urine by means of a quantitative measurement in serum and urine and as qualitative determination in urine as point of care method.

Serum and urine (patent pending) from healthy donors were spiked with dabigatran (50ng/ml to 1000 ng). Thrombin inhibition was determined by means of a chromogenic substrate method comparing the results obtained from plasma. The reagents were lyophilized on mini-strips and incubated with urine (patent pending). The concentration of dabigatran was determined from plasma, serum, and urine and qualitatively by the mini-strips from 15 patients on treatment with dabigatran.

The concentrations of dabigatran spiked to plasma, serum and urine were independent of the medium (correlation between r=0.80 and 0.93). Patients on treatment with dabigatran showed a high correlation of plasma and serum values (r=0.9). The correlation to urine samples was lower do to the time dependence of drug intake. The qualitative mini-strips detected dabigatran in all samples independently of drug intake. There were no false positive or false negative detections of dabigatran by the mini-strips.

Detection of dabigatran in serum avoids separate blood sampling to obtain plasma. Detection in urine avoids blood sampling at all and allows point of care testing also by the patient him/herself. Control of intake and early detection of low urinary excretion leading to increased plasma levels of dabigatran may improve and facilitate patient care.