Measurement of rivaroxaban and apixaban in serum samples of patients

Abstract

BackgroundThe determination of rivaroxaban and apixaban from serum samples of patients may be beneficial in specific clinical situations when additional blood sampling for plasma and thus the determination of factor Xa activity is not feasible or results are not plausible.Materials and methodsThe primary aim of this study was to compare the concentrations of rivaroxaban and apixaban in serum with those measured in plasma. Secondary aims were the performance of three different chromogenic methods and concentrations in patients on treatment with rivaroxaban 10 mg od (n = 124) or 20 mg od (n = 94) or apixaban 5 mg bid (n = 52) measured at different time.ResultsConcentrations of rivaroxaban and apixaban in serum were about 20–25% higher compared with plasma samples with a high correlation (r = 0·79775–0·94662) using all assays (all P < 0·0001). The intraclass correlation coefficients were about 0·90 for rivaroxaban and 0·55 for apixaban. Mean rivaroxaban concentrations were higher at 2 and 3 h compared with 1 and 12 h after administration measured from plasma and serum samples (all P-values < 0·05) and were not different between 1 vs. 12 h (plasma and serum).ConclusionsThe results indicate that rivaroxaban and apixaban concentrations can be determined specifically from serum samples.

Measurement of dabigatran, rivaroxaban and apixaban in samples of plasma, serum and urine, under real life conditions. An international study

“…The correlation of the concentrations of apixaban and rivaroxaban in plasma and serum was high (r > 0.9) but was low for dabigatran. This latter finding is in line with earlier observations and could be explained by a consumption of dabigatran during blood clotting to obtain serum after blood collection [21]. Regarding urine samples the high renal excretion of NOAC was confirmed by the tests used here reflecting renal clearances of NOAC ranging from 25% (apixaban) to 80% (dabigatran).…”

“…For apixaban reported results differ considerably from those determined here [28] (239 ng/mL/128 ng/mL) most likely due to the low number of patients. The coefficients of variation were also in similar ranges for apixaban (our study/reference study: 50%/37%) using chromogenic assays [21] and for rivaroxaban (66%/36%-82%) using mass spectrometry [29] or chromogenic assays [30] and dabigatran (50%/44%-134%) using mass spectrometry [7] or chromogenic assays [30]. Thus, the present results demonstrate that in an inter-laboratory study the chromogenic methods lead to a variance of NOAC concentrations, which is comparable to that of the above mentioned monocentric evaluations.…”

“…The feasibility of the measurement of concentrations of rivaroxaban, apixaban [21] and dabigatran [31] in plasma, serum and urine and in urine samples as quantitative and as qualitative POCT methods [31] appears to be given as the results were similar when tests were performed at several centres. The correlation of the concentrations of apixaban and rivaroxaban in plasma and serum was high (r > 0.9) but was low for dabigatran.…”

“…So far, measurements under real life conditions have been described for prothrombin time and activated partial thromboplastin time tests from whole blood [20], chromogenic tests from serum and urine [21] and specific POCT colour tests from urine samples [22]. Here we analysed in a larger international, multicentre study, the anticoagulant effects in plasma as well as in serum and urine samples and with a POCT in urine from patients treated with dabigatran, rivaroxaban and apixaban under real life conditions.…”

Determination of dabigatran in plasma, serum, and urine samples: comparison of six methods

“…Therefore, we compared six assays mostly used for plasma samples and two chromogenic assays to analyze dabigatran in serum and urine samples from patients on treatment under real-life conditions. To analyze the performance of these assays, we adopted various statistical methods including the BlandAltman analysis as used previously for the determination of rivaroxaban and apixaban [22].…”