· Adults:
o Subcutaneous (SC): 5,000 IU every 8–12 hours, starting 2 hours before surgery or as per protocol.
o Intravenous (IV): 5,000 IU bolus followed by 1,000–2,000 IU/hour continuous infusion, or 5,000–10,000 IU every 4–6 hours.
· Children: 250 IU/kg SC every 12 hours.
· Elderly: Initiate at lower doses with close monitoring.
· Adults:
o IV Loading Dose: 5,000 IU bolus.
o Continuous Infusion: 1,000 IU/hour, adjusted based on activated partial thromboplastin time (aPTT).
· Children: 50–100 IU/kg IV bolus, followed by 400–600 IU/kg/day continuous infusion.
· Monitoring: Adjust infusion to maintain aPTT within the therapeutic range (usually 1.5–2.5 times the control value).
· ST-Elevation Myocardial Infarction (STEMI):
o IV Bolus: 60–70 IU/kg (maximum 5,000 IU).
o Continuous Infusion: 12–15 IU/kg/hour (maximum 1,000 IU/hour).
· Non-ST Elevation Myocardial Infarction (NSTEMI) and Unstable Angina:
o IV Bolus: 60–70 IU/kg (maximum 5,000 IU).
o Continuous Infusion: 12–15 IU/kg/hour (maximum 1,000 IU/hour).
· Monitoring: Adjust infusion to maintain aPTT within the therapeutic range.
· Hemodialysis:
o Initial Dose: 25–30 IU/kg IV bolus.
o Maintenance Infusion: 1,500–2,000 IU/hour.
· Cardiopulmonary Bypass: Dosage is individualized based on patient and circuit characteristics; continuous monitoring of aPTT is recommended.
· Neonates and Infants:
o IV Loading Dose: 75–100 IU/kg.
o Continuous Infusion: 28 IU/kg/hour for infants under 2 months; 20 IU/kg/hour for children over 1 year.
· Monitoring: Frequent monitoring of aPTT is essential to adjust dosing appropriately.
· Renal Impairment: Heparin is primarily cleared by the liver; however, in severe renal impairment, dosing adjustments may be necessary.
· Hepatic Impairment: Use with caution; monitor for signs of bleeding and adjust dosing as needed.
· Pregnancy: Heparin does not cross the placenta and is considered safe during pregnancy.
· Breastfeeding: Heparin is excreted in breast milk in negligible amounts and is considered safe during breastfeeding.
· Elderly: Initiate therapy at lower doses with close monitoring due to increased risk of bleeding.
Heparin sodium is an anticoagulant that enhances the activity of antithrombin III (ATIII), a natural inhibitor of several coagulation enzymes. By binding to ATIII, heparin accelerates its ability to inactivate thrombin (factor IIa), factor Xa, and other activated clotting factors, thereby preventing conversion of fibrinogen to fibrin and inhibiting clot formation. This effect leads to decreased blood clot formation and propagation, reducing the risk of thrombosis.