Smaller doses of protamine can be given if the time since LMWH exceeds 8 hours. A second dose of protamine 0.5mg/100iu is given if the bleeding persists. The dose is calculated for the LMWH given in the last 8 hours. LMWH has no specific antidote for its reversal but protamine will neutralise approximately 60% of its anticoagulant effect. Neutralisation of subcutaneously administered heparin may require a prolonged infusion of protamine as it has a half-life of approximately 7 minutes. Given heparin ‘s half-life only that given during the preceding 4hrs needs to be considered a patient receiving a continuous IV infusion of heparin at 1000iu/hr requires approximately 40 mg of protamine to neutralise heparin given in the past 4hrs. UFH is reliably and rapidly reversed with protamine sulphate, which binds to heparin to form a stable salt. It is worth noting patients given treatment dose UFH are routinely monitored (with APTT) and the dose adjusted to achieve the desired therapeutic range unlike LMWH and Factor Xa inhibitors which are not. ![]() The following approach describes the specific management of patients with bleeding when taking parenteral anticoagulants. įondaparinux is a parenteral Factor Xa inhibitor like LMWH and similarly has no anti-thrombin activity, facilitating a more subtle regulation of coagulation with a safer therapeutic window. It is worth noting that LMWHs are cleared principally by the kidneys so should be avoided or dose reduced in patients with renal impairment were UFH is preferable. This reduced ability to bind plasma proteins is responsible for its predictable dose-response relationship, longer plasma half-life, and lower risk of heparin-induced thrombocytopenia and osteopenia. The main difference between UFH and LMWH is that the latter has relatively lower binding properties to plasma proteins, and a significantly reduced ability to inactivate thrombin. By inactivating thrombin, heparin not only prevents fibrin formation but also inhibits thrombin-induced activation of platelets. It produces its major anticoagulant effect by inactivating thrombin and activated factor X (factor Xa). Heparin and its derivatives are the most widely used parenteral anticoagulants in the UK, for the treatment and prophylaxis of thrombo-embolic disease. Parenteral Anticoagulants Heparins/Fondaparinux ![]() Apixaban and fondaparinux) or are usually monitored using indirect tests (Dabigatran). ![]() Whereas UFH, LMWH, and warfarin therapy all can be monitored using either indirect or more specific quantitative assays, many of the novel anticoagulants are either not routinely monitored (e.g. ![]() The use of novel anticoagulants is complicated by a lack of easily available laboratory tests to measure their levels and thereby optimize their clinical benefit and safety. Transfusion packed red cells, platelets, etc.Local or surgical Haemostatic measures also agents like tranexamic acid.Supportive treatment volume resuscitation and inotropic support.Hold further doses of the anticoagulant.The general principles for the management of haemorrhage in the anticoagulated patient detailed using the mnemonic:
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