Summary
Therapeutic oral anticoagulation is still commonly achieved by administration of warfarin
or other vitamin K antagonists that are associated with an untoward pharmacokinetic
/ pharmacodynamic (PK/PD) profile leading to a high incidence of bleeding complications
or therapeutic failure. Hence, there is an unmet medical need of novel easy-to-use
oral anticoagulants with improved efficacy and safety. Recent developments include
the identification of non-peptidic small-molecules that selectively inhibit certain
serine proteases within the coagulation cascade. Of these, the thrombin inhibitor
dabigatran and factor Xa inhibitor rivaroxaban have recently been licensed for thromboprophylaxis
after orthopaedic surgery mainly in Europe. In addition, the factor Xa inhibitor apixaban
is in late-stage clinical development. Each drug is prescribed at fixed doses without
the need of anticoagulant monitoring. Phase III trials in orthopaedic patients essentially
resulted in non-inferior efficacy of dabigatran and superior efficacy of rivaroxaban
over enoxaparin without any marked differences of drug safety, while apixaban data
is still controversial. However, alterations of rivaroxaban and apixaban pharmacokinetics
upon interactions with inhibitors and inducers of CYP3A4 or P-glycoprotein may complicate
the use of these compounds in daily practice, whereas dabigatran elimination largely
depends on renal function. Hence, this review reports PK/PD, efficacy and safety data
of dabigatran, rivaroxaban and apixaban throughout preclinical and clinical development.
Keywords
Clinical trials - oral anticoagulants - venous thrombosis - pharmacodynamics - pharmacokinetics
- drug design