Apixaban

Class	Factor Xa inhibitor
Chemistry	Oxazolidinone
Routes of administration	Oral only
Absorption	Rapidly absorbed Oral bioavailability ~50% Maximum blood concentration about 90-200 minutes after administration
Solubility	pKa 13.1; practically insoluble in water
Distribution	VOD=0.3L/kg; 87% protein-bound
Metabolism	33% is metabolised in the liver: a substrate of CYP3A4/5 Inactive sulfate conjugates are renally excreted
Elimination	Hepatic metabolism, renal excretion and biliary secretion are each responsible for elimination of approximately one-third of dose. 33% renal excretion of unchanged drug 33% biliary and intestinal secretion of unchanged drug 33% hepatic metabolism
Time course of action	Half life = 12 hours
Target receptor	Factor Xa
Mechanism of action	Apixaban inhibits free factor Xa as well as prothrombinase-bound and clot-associated factor Xa, in contrast to drugs like fondaparinux which only act on free Xa. Factor Xa is the active form of Factor X (activated by either the intrinsic or extrinsic pathway); its job is to cleave prothrombin into thrombin. Thus, apixaban prevents thrombin generation.
Clinical effects	Bleeding, peripheral oedema, fatigue
Literature reference	TGA PI document
CICM details of understanding	Level 2
Mentioned around Deranged Physiology	Warfarin and other oral anticoagulants
Related SAQs