Direct Xa inhibitor

Direct factor Xa inhibitors ( ' xabans') are a class of anticoagulant drugs which act directly upon Factor X in the coagulation cascade, without using antithrombin as a mediator.

Clinical uses
Direct factor Xa inhibitors are being used clinically. Clinical trials published in journals such as the New England Journal of Medicine and The Lancet have shown promise for these compounds as substitutes for the currently administered vitamin K antagonists or low molecular weight heparin. Advantages of orally administered direct Xa inhibitors lie in the fact that they have a predictable effect, do not require frequent monitoring or re-dosing, are given through the mouth and not by injection and have few (known) drug interactions. Disadvantages include the currently limited prospective experience and the theoretical interactions with statin medication, as they are metabolized at least in part by the same cytochrome enzyme, CYP3A4.

Examples
A naturally occurring inhibitor of factor Xa was first reported in 1987. Tuszynski et al. discovered antistasin, which was isolated from the extracts of Mexican leach, Haementeria officinalis. Soon after this, another naturally occurring inhibitor, tick anticoagulant peptide (TAP) was isolated from the extract of tick Ornithodoros moubata.

Examples include:
 * Apixaban
 * Edoxaban
 * Otamixaban
 * Rivaroxaban
 * YM466