What are the pharmacokinetic advantages of LMWHs?
LMWHs have pharmacokinetic advantages over heparin; after subcutaneous injection, the bioavailability of LMWHs is about 90% and LMWHs produce a more predictable anticoagulant response than heparin. The elimination half-life of LMWHs, which is 3 to 6 h after subcutaneous 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 prolonged in patients with renal failure.