Anticoagulants / ATIII Activators / Pharmacokinetics
Activators of Antithrombin III: HEPARIN,
FONDAPARINUX, LMW HEPARINS: DALTEPARIN, DANAPAROID, ENOXAPARIN
Pharmacokinetics
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activity is standardized by bioassay
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must be given IV or SC (not active orally; IM administration causes hematomas)
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rapid effect (within minutes); instantaneously in vitro
- HEPARIN dose is adjusted to double partial thromboplastin time and is monitored via aPTT
- LMW HEPARINS and FONDAPARINUX have more predictable pharmacology, and are not generally monitored
- metabolized in liver; excreted in urine → must monitor closely in patients in renal failure
- HEPARIN does not cross the placenta → drug of choice for anticoagulation during pregnancy