Background: Knowledge related to expected peak concentrations of apixaban in children and adolescent populations is very scarce, since it has only recently been approved for treatment in pediatric population.

Aims: To compare peak plasma concentrations of apixaban in adolescents and adults.

Methods: Innovance heparin (Siemens Healthineers, Germany) calibrated with apixaban calibrators (Hyphen BioMed, France) was used for quantitative determination of apixaban concentration. The study included plasma samples from adult patients (N=80; 47-89 yrs) treated with standard dose (2×5 mg/day) and from adolescents (N=59; 13-22 yrs) treated with two dosing regimens: 2×2.5 mg/day (N=38) and 2×5 mg/day (N=21). Blood samples were taken two to four hours after drug administration in order to obtain peak apixaban concentrations. The study was funded by the Croatian Science Foundation as part of the research project IP-2016-06-8208. Statistical analysis was done using Wilcoxon test by MedCalc Statistical Software version 11.5.1.

Results: Concentrations of apixaban showed significantly lower peak values in adolescents treated with 2×2.5 mg/day compared with those treated with 2×5 mg/day (P=0.003), as well as compared with adults treated 2×5 mg/day (P<0.001). On the contrary, peak concentrations between adolescents and adults treated with the same standard dose of 2×5 mg/day did not differ (P=0.937) (Figures 1 and 2). In both populations, adolescents and adults, treated with the same standard dose of 2×5 mg/day, peak concentrations showed very good agreement with the published expected values in adult patients.

Results of apixaban concentrations in adolescents and adults.Differences between apixaban concentrations in adolescents and adults depending on dose regimens: adolescents 2×2.5 and 2×5 mg/day (a), adolescents 2×2.5 and adults 2×5 mg/day (b) and adolescents 2×5 and adults 2×5 mg/day (c).

Conclusions: Peak plasma concentrations of apixaban in adolescents depend on the dose regimen (2×2.5 vs. 2×5 mg/day) showing roughly a twice lower values in plasma of adolescents treated with a twice lower doses. Further, peak concentrations in adolescents treated with standard dose regimen of 2×5 mg/day are completely comparable with values in adult patients with the same dosing regimen as well as with the expected values published for adult patients.

« Back to ISTH 2021 Congress

ISTH Congress Abstracts - https://abstracts.isth.org/abstract/comparison-of-peak-plasma-concentrations-of-apixaban-in-adolescent-and-adult-patients/