Andexanet Alfa, the Possible Alternative to Protamine for Reversal of Unfractionated Heparin.

The recent shortage of protamine prompted an investigation of alternatives for reversal of unfractionated heparin. Heparin is an anticoagulant utilized in the hospital setting. Available options for anticoagulation include direct oral anticoagulants, vitamin K antagonists, thrombin inhibitors, low-molecular-weight heparins, and heparin. Protamine is the approved reversal agent for heparin with few alternatives under investigation. Although andexanet was designed as an antidote for apixaban and rivaroxaban, in vitro studies show that in a dose-dependent technique, andexanet had near full reversal of heparin, reversed anti-factor Xa activity, and neutralized anticoagulant effects of activated partial thromboplastin time and thrombin time induced by heparin.