The most serious adverse effect is bleeding, including severe internal bleeding.<unk>  is associated with lower rates of serious and fatal bleeding events than warfarin but is associated with higher rates of bleeding in the gastrointestinal tract. , post-marketing assessments showed liver toxicity, and further studies are needed to quantify this risk. In 2015,<unk>  accounted for the highest number of reported cases of serious injury among regularly monitored medications to the FDA's Adverse Events Reporting System (AERS). Reversal agent In October 2014, Portola Pharmaceuticals completed Phase I and II clinical trials for andexanet alfa as an antidote for Factor Xa inhibitors with few adverse effects, and started Phase III trials. Andexanet alfa was approved by the U.S. Food and Drug Administration in May 2018, under the trade name AndexXa.
Rivaroxaban
Apixaban
Dabigatran
Ticlopidine
Enoxaparin sodium
Ticagrelor
Eptifibatide
Palladin