HEPARIN SODIUM 25,000 UNITS IN DEXTROSE 5% IN PLASTIC CONTAINER
Clinical safety rating: safe
Other drugs that affect hemostasis increase bleeding risk Can cause heparin-induced thrombocytopenia (HIT) and bleeding.
Heparin binds to antithrombin III, accelerating its inhibition of thrombin (factor IIa) and factor Xa, thereby preventing fibrin clot formation.
| Metabolism | Heparin is primarily cleared through the liver (via desulfation and depolymerization) and also undergoes non-linear saturable elimination via binding to cells and proteins. A portion is excreted unchanged in urine. |
| Excretion | Renal: minimal intact heparin; primarily hepatic degradation via desulfation and depolymerization into inactive metabolites (uroheparin) excreted renally. Biliary/fecal: negligible (<1%). |
| Half-life | 30–90 minutes (mean 1.5 h) for therapeutic doses; dose-dependent and saturable elimination: increases with dose (e.g., 100 U/kg: ~56 min; 400 U/kg: ~152 min). At lower doses, half-life may be shorter due to rapid clearance. |
| Protein binding | High, primarily to antithrombin III (ATIII; ~90%), also to albumin and other proteins. Overall >95% bound at therapeutic concentrations. |
| Volume of Distribution | 0.05–0.07 L/kg (limited to plasma volume; reflects minimal extravascular distribution). |
| Bioavailability | Subcutaneous: 20–30% (erratic absorption). Intravenous: 100%. |
| Onset of Action | Intravenous: immediate (within 1–2 minutes). Subcutaneous: 20–30 minutes. |
| Duration of Action | Intravenous: 2–6 hours (dose-dependent). Subcutaneous: 8–12 hours (prolonged by depot effect). Note: individual variability; monitoring aPTT required. |
| Molecular Weight | 15000 |
Initial IV bolus of 80 units/kg, followed by continuous IV infusion at 18 units/kg/hour; subsequent dosing based on aPTT. For DVT/PE: initial bolus of 5,000 units or 80 units/kg, then 1,000-2,000 units/hour continuously.
| Dosage form | INJECTABLE |
| Renal impairment | No specific GFR-based dose adjustment; however, patients with severe renal impairment (CrCl < 30 mL/min) may have prolonged half-life and require more frequent aPTT monitoring, but no dose reduction is standard. |
| Liver impairment | No specific Child-Pugh based dosing; patients with hepatic impairment may have coagulopathy and require careful monitoring. |
| Pediatric use | Loading dose: 75-100 units/kg IV over 10 minutes; maintenance infusion: 20-28 units/kg/hour for age < 1 year, 18-20 units/kg/hour for age ≥ 1 year; titrate to target aPTT. |
| Geriatric use | Increased risk of bleeding; use lower initial dosing (e.g., 60 units/kg bolus) and lower infusion rates (e.g., 12-15 units/kg/hour) with frequent aPTT monitoring. |
| 1st trimester | Heparin does not cross the placenta due to high molecular weight and is not associated with teratogenicity; considered safe when indicated. |
| 2nd trimester | No known fetal risk; used when anticoagulation is required. |
| 3rd trimester | Avoid near term due to risk of maternal hemorrhage and epidural/spinal hematoma; generally safe if monitoring is rigorous. |
Clinical note
Other drugs that affect hemostasis increase bleeding risk Can cause heparin-induced thrombocytopenia (HIT) and bleeding.
| FDA category | Human |
| Placental transfer | Does not cross placenta due to high molecular weight and negative charge. |
| Breastfeeding |
■ FDA Black Box Warning
Heparin is contraindicated in patients with severe uncontrolled hypertension, history of heparin-induced thrombocytopenia (HIT), and in those with known hypersensitivity to heparin. Use with caution in patients with bleeding disorders.
| Common Effects | bleeding |
| Serious Effects |
Active major bleedingHistory of heparin-induced thrombocytopenia (HIT)Severe uncontrolled hypertensionKnown hypersensitivity to heparinEpidural or spinal anesthesia (risk of spinal hematoma)
| Precautions | Monitor platelet counts regularly due to risk of heparin-induced thrombocytopenia (HIT), Monitor for signs of bleeding; adjust dose in renal impairment, Avoid intramuscular injection (risk of hematoma), Use with caution in patients with liver disease, renal failure, or history of gastrointestinal ulcers |
| Food/Dietary |
Loading safety data…
| Heparin is not excreted into breast milk due to its high molecular weight and negative charge; considered compatible with breastfeeding. |
| Lactation Rating | Safe |
| Teratogenic Risk | Heparin does not cross the placenta and is not associated with teratogenic risk. No increased risk of fetal malformations has been reported in any trimester. |
| Fetal Monitoring | Monitor maternal activated partial thromboplastin time (aPTT) to maintain therapeutic range (1.5-2.5 times control). Assess platelet count every 2-3 days for heparin-induced thrombocytopenia. Monitor for signs of bleeding (epistaxis, hematuria, ecchymosis). Fetal surveillance includes ultrasound for growth and Doppler studies if placental insufficiency is suspected. |
| Fertility Effects | No known direct effects on fertility. Heparin is not associated with impairment of reproductive function in human studies. |
| No specific food interactions. Avoid vitamin K-rich foods (e.g., leafy greens) if also on warfarin; not relevant for heparin alone. Avoid alcohol due to increased bleeding risk. |
| Clinical Pearls | Monitor aPTT 6 hours after initiation and after dose changes, titrate to 1.5-2.5 times control. Use weight-based dosing: 80 units/kg bolus then 18 units/kg/hr. HIT panel for platelets dropping >50% or <100,000. Protamine 1mg per 100 units heparin to reverse. Do not give IM injections. Use preservative-free heparin for neonates. |
| Patient Advice | You will receive blood tests (aPTT) regularly to check the effect of this medication. · Report any unusual bleeding, bruising, black/tarry stools, or blood in urine or vomit. · Use a soft toothbrush and electric razor to avoid cuts. · Avoid aspirin, NSAIDs (like ibuprofen), and alcohol while on this medication. · Wear a medical alert bracelet stating you take heparin. · Do not take any new medications without consulting your doctor. · This is a clear solution; do not use if discolored or containing particles. |