RT Book, Section A1 Howland, Mary Ann A2 Nelson, Lewis S. A2 Howland, Mary Ann A2 Lewin, Neal A. A2 Smith, Silas W. A2 Goldfrank, Lewis R. A2 Hoffman, Robert S. SR Print(0) ID 1163002643 T1 Protamine T2 Goldfrank's Toxicologic Emergencies, 11e YR 2019 FD 2019 PB McGraw-Hill Education PP New York, NY SN 9781259859618 LK accesspharmacy.mhmedical.com/content.aspx?aid=1163002643 RD 2024/03/29 AB Protamine is a rapidly acting antidote that physically complexes unfractionated heparin (UFH) and reverses its anticoagulant effects. Protamine neutralizes the anti-IIa activity of low-molecular-weight heparin (LMWH) and incompletely neutralizes the anti-Xa activity of LMWH, which often normalizes the activated partial thromboplastin time (aPTT) and the thrombin time but minimally affects the anti–factor Xa activity and cannot be expected to limit hemmorhage. Protamine has no effect on heparin pentasaccharide fragments or analogs such as fondaparinux.