摘要
The objective was to characterise apixaban pharmacodynamic (PD) activity in umbilical cord (UC), paediatric, and adult plasma. Plasma was obtained from blood samples from six UC donors, 70 paediatric (neonates [birth-<= 1 month], infants (>1-<= 6 months], toddlers [>6 months-<= 2 years], young children [>2-<= 6 years], children [>6-<= 12 years], adolescents [>12-<= 18 years]), and six adult (19-45 years) subjects. Plasma spiked with apixaban 0 (baseline), 30, or 110 ng/ml was analysed for anti-factor Xa activity, factor X levels, prothrombin time (PT), and modified PT (mPT). Apixaban had similar concentration related effects on anti-factor Xa activity across groups (30 ng/ml: 0.223-0.295IU/nnl; 110 ng/ml: 1.212-1.474 IU/ml). Endogenous baseline factor X levels were 43%-68% lower in plasma from UC and subjects <= 6 months versus adults. Factor Xa inhibition (percentage change from baseline in apparent factor X levels) was similar for both apixaban concentrations across groups, except UC, neonate, and infant groups, which showed greater inhibition vs adults for apixaban 110 ng/ml. Baseline PT and mPT were similar across groups. Apixaban had no effect on PT at the concentrations tested. Apixaban 110 ng/ml prolonged mPT similarly across groups (44.4-53.2 s to 64.5-70.0 s); no prolongation was found with apixaban 30 ng/ml. Apixaban demonstrated consistent concentration-related effects on other PD endpoints in plasma samples from all age groups, except factor Xa inhibition.
- 出版日期2017-8