HEPARIN SODIUM 25,000 UNITS IN SODIUM CHLORIDE 0.9% IN PLASTIC CONTAINER
Clinical safety rating: safe
No significant drug interactions Can cause hypernatremia and fluid overload.
Heparin binds to antithrombin III, inducing a conformational change that accelerates the inactivation of thrombin (factor IIa) and activated factor X (Xa), thereby inhibiting coagulation.
| Metabolism | Primarily cleared by the reticuloendothelial system and partially metabolized in the liver (desulfation and depolymerization). Dose-dependent renal elimination of smaller molecular weight fragments. |
| Excretion | Renal (clearance primarily via reticuloendothelial system and liver, with minimal renal excretion of intact heparin; metabolites eliminated renally; <5% excreted unchanged in urine) |
| Half-life | 1.5 hours (dose-dependent and increases with higher doses; e.g., 2.5 hours after 25,000 units IV; prolonged in hepatic or renal impairment) |
| Protein binding | 95-98% (binds to antithrombin III, albumin, lipoproteins, fibrinogen, and factor V) |
| Volume of Distribution | 0.06-0.1 L/kg (primarily confined to intravascular space; minimal extravascular distribution) |
| Bioavailability | Subcutaneous: 20-30% (due to limited absorption and first-pass hepatic metabolism); IV: 100% |
| Onset of Action | IV: immediate; subcutaneous: 20-30 minutes |
| Duration of Action | IV: 2-6 hours (dose-dependent; may be prolonged with high doses or hepatic/renal impairment); subcutaneous: 8-12 hours (may extend with high doses) |
IV infusion: Initial bolus 80 units/kg, then continuous infusion at 18 units/kg/hr. Adjust based on aPTT. Subcutaneous: 5,000-10,000 units every 8-12 hours.
| Dosage form | INJECTABLE |
| Renal impairment | No specific dose adjustment for heparin based on GFR. However, caution in severe renal impairment (CrCl <30 mL/min) due to increased bleeding risk. Use with careful monitoring. |
| Liver impairment | Heparin is primarily metabolized in the liver. In Child-Pugh class B or C, dose may need reduction due to prolonged half-life. No specific dose recommendations; monitor aPTT closely. |
| Pediatric use | IV infusion: Initial bolus 75-100 units/kg over 10 minutes, then maintenance 20-25 units/kg/hr for infants <1 year; 18-20 units/kg/hr for children >1 year. Adjust based on aPTT. |
| Geriatric use | Elderly patients may have reduced renal function and increased bleeding risk. Lower initial infusion rates (15-18 units/kg/hr) and more frequent aPTT monitoring recommended. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
No significant drug interactions Can cause hypernatremia and fluid overload.
| FDA category | Animal |
| Breastfeeding | Heparin is not excreted into breast milk due to high molecular weight and protein binding. M/P ratio not applicable; considered compatible with breastfeeding. No adverse effects on nursing infants reported. |
| Teratogenic Risk | Heparin does not cross the placenta and is not associated with fetal teratogenicity. No increased risk of congenital anomalies reported. First trimester: no evidence of teratogenic effects. Second and third trimesters: no fetal risk; may be used for maternal conditions (e.g., VTE treatment). |
■ FDA Black Box Warning
Heparin is contraindicated in patients with a history of heparin-induced thrombocytopenia (HIT) or heparin-induced thrombocytopenia with thrombosis (HITT). Monitor platelets closely; fatal hemorrhage can occur.
| Common Effects | fluid replacement |
| Serious Effects |
["History of heparin-induced thrombocytopenia (HIT) or HITT","Active major bleeding or bleeding disorders (e.g., hemophilia, thrombocytopenia)","Severe uncontrolled hypertension","Recent surgery or trauma with high bleeding risk","Hypersensitivity to heparin or porcine products","Spinal or epidural anesthesia (risk of spinal hematoma)"]
| Precautions | ["Risk of bleeding, especially at high doses; monitor coagulation parameters (aPTT)","Heparin-induced thrombocytopenia (HIT) risk; monitor platelet counts","Hyperkalemia due to suppression of aldosterone synthesis","Osteoporosis with long-term use","Hypersensitivity reactions including urticaria, angioedema, and anaphylaxis"] |
Loading safety data…
| Fetal Monitoring | Monitor maternal platelet count for heparin-induced thrombocytopenia; activated partial thromboplastin time (aPTT) for anticoagulation; signs of bleeding. Fetal monitoring: ultrasound for growth if used long-term; no direct fetal monitoring required. |
| Fertility Effects | No known impact on fertility in males or females. Does not affect ovulation, implantation, or spermatogenesis. |