The aPTT can be used to assess the effectiveness of protamine sul- fate neutralization of the anticoagulant effects of The risk of severe adverse reactions to protamine sulfate, such as hypotension or bradycardia, can be minimized by administering the protamine slowly. Table 4 Methods for Preparation of LMWH and Danaparoid Agent Method of Preparation Bemiparin Alkaline degradation Dalteparin (Fragmin) Nitrous acid depolymerization Danaparoid sodium (Orgaran) Prepared from animal gut mucosa; contains heparan sulfate (84%), dermatan sulfate (12%), and chondroitin sulfate (4%) Enoxaparin sodium (Lovenox/Clexane) Benzylation followed by alkaline depolymerization Nadroparin calcium (Fraxiparine) Nitrous acid depolymerization Tinzaparin (Innohep) Enzymatic depolymerization with heparinase LMWH5low-molecular-weight heparin. 2012 American College of Chest Physicians by Kimberly Henricks on February 10, 2012 chestjournal.chestpubs.org Downloaded from e30S Parenteral Anticoagulants trials have shown that LMWHs are safe and effective for the prevention and treatment of VTE and for the treatment of non-ST-elevation acute coronary syndromes. 1.2.2 Pharmacokinetics: LMWHs have pharmaco- kinetic advantages over heparin;115,116,121 after subcu- taneous injection, the bioavailability of LMWHs is about 90% and LMWHs produce a more predictable anticoagulant response than heparin.126 The elimina- tion half-life of LMWHs, which is 3 to 6 h after sub- cutaneous injection, is dose independent, and anti-Xa levels peak 3 to 5 h after dosing. One limitation of LMWHs is that they are predominately cleared by the kidneys so their biologic half-life may be pro- longed in patients with renal failure.127,128 1.2.3 Monitoring Antithrombotic Effect: LMWHs are typically administered in xed or weight-adjusted doses for thromboprophylaxis and in weight-adjusted doses for therapeutic purposes. 