Apixaban
Apixaban. Selective, reversible direct inhibitor of activated factor X (FXa). Blocks both free and prothrombinase-bound Xa → decreased thrombin… Oral half-life 12 h.
Selective, reversible direct inhibitor of activated factor X (FXa). Blocks both free and prothrombinase-bound Xa → decreased thrombin generation. No antithrombin III cofactor required (distinct from heparin). Rapid onset (peak anticoagulant effect within 3 h). Andexanet alfa is the specific reversal agent.
PK: F 0.662 is verbatim and was the only sound value, but it cannot be kept alongside the replacement volume: the published 28.2 L is APPARENT, so F is pinned to 1 and the measured bioavailability recorded here instead. V 21 L was a number picked from inside a stated "17 to 26 L" range and is not even its midpoint; half-life 11.5 h appears nowhere. THE EFFECT COMPARTMENT IS REMOVED BECAUSE ITS OWN CITATION REFUTES IT: "Anti-FXa activity and mPT changes followed the apixaban plasma concentration-time profile; both were highly correlated with concentration (R2 = 0.99 and R2 = 0.93)". The effect is not decoupled, so a delay is structurally wrong. Two references carry no pharmacokinetics — an outcomes trial and a RABBIT thrombosis study.
Pharmacokinetics
- Oral — t½ 12 h · F 100% · ka 0.781 h⁻¹ · Vd 28.2 L
Related compounds
- Warfarin — caution
- Aspirin — caution
- NSAIDs — caution
- Rivaroxaban — caution
Sources: PMID:34342172, PMID:15911722, PMID:31089975, PMID:39449344, PMID:35680619