HEPARIN SODIUM 5,000 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 (ATIII) via a unique pentasaccharide sequence, inducing a conformational change that accelerates ATIII-mediated inactivation of factor Xa and thrombin (factor IIa). This prevents fibrin formation and clot propagation. It also inhibits factors IXa, XIa, and XIIa.
| Metabolism | Heparin undergoes desulfation and partial depolymerization by reticuloendothelial system (liver, spleen) and is cleared by a combination of saturable (cellular uptake) and non-saturable (renal) mechanisms. Low molecular weight fractions are renally excreted. |
| Excretion | Renal: negligible; biliary/fecal: negligible; primarily cleared by hepatic depolymerization and reticuloendothelial system uptake. |
| Half-life | 30–150 minutes (intravenous), dose-dependent; at therapeutic doses ~60 minutes; prolonged in hepatic disease. |
| Protein binding | High, ~95%; binds to antithrombin III, albumin, lipoproteins, and fibrinogen. |
| Volume of Distribution | 0.04–0.07 L/kg; confined primarily to plasma volume. |
| Bioavailability | Subcutaneous: ~20–30%; intravenous: 100%; not absorbed orally. |
| Onset of Action | Intravenous: immediate; subcutaneous: 20–60 minutes. |
| Duration of Action | Intravenous: 2–6 hours (dose-dependent); subcutaneous: 8–12 hours; prolonged in renal impairment. |
Continuous IV infusion: Initial bolus of 5,000 units, then 1,000 units/hour (25,000 units/24h) adjusted based on aPTT. Typical infusion rate 10-20 units/kg/hour.
| Dosage form | INJECTABLE |
| Renal impairment | No specific GFR-based dose adjustment required; heparin is not significantly renally cleared. Monitor aPTT closely in severe renal impairment (CrCl <30 mL/min) due to potential accumulation of antithrombin III-heparin complex. |
| Liver impairment | Child-Pugh A: No adjustment. Child-Pugh B and C: No specific dose adjustment, but increased monitoring due to potential coagulopathy and altered response. |
| Pediatric use | Initial bolus: 75-100 units/kg IV; maintenance infusion: 20-25 units/kg/hour for infants, 18-20 units/kg/hour for children, adjusted to target aPTT 60-85 seconds. |
| Geriatric use | Consider lower initial doses due to reduced clearance and increased bleeding risk; use actual body weight; monitor aPTT more frequently; typical starting infusion 10-15 units/kg/hour. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Other drugs that affect hemostasis increase bleeding risk Can cause heparin-induced thrombocytopenia (HIT) and bleeding.
| FDA category | Human |
| Breastfeeding | Heparin is not excreted into breast milk due to high molecular weight; M/P ratio not applicable. Compatible with breastfeeding; no adverse effects reported. |
| Teratogenic Risk | Heparin does not cross the placenta; therefore, it is not associated with teratogenicity. No increased risk of congenital anomalies in first trimester. Second and third trimesters: safe for fetal development, but risk of maternal hemorrhage and placental abruption requires monitoring. |
■ FDA Black Box Warning
Heparin-induced thrombocytopenia (HIT). Spinal/epidural hematomas in patients receiving neuraxial anesthesia or spinal puncture, especially with concomitant anticoagulants or antiplatelet agents.
| Common Effects | bleeding |
| Serious Effects |
["History of heparin-induced thrombocytopenia (HIT) or heparin-induced thrombocytopenia with thrombosis (HITT)","Active bleeding (except when due to DIC)","Severe thrombocytopenia (platelet count < 100,000/μL)","Uncontrolled bleeding disorders (e.g., hemophilia, von Willebrand disease)","Known hypersensitivity to heparin or pork products","Inability to perform appropriate coagulation monitoring (e.g., aPTT)","Intramuscular injection (risk of hematoma)","Relative: Recent major surgery (especially of CNS, eye, or spinal cord), recent hemorrhagic stroke, severe hypertension, bacterial endocarditis, threatened abortion, liver disease with coagulopathy, renal failure"]
| Precautions | ["Risk of heparin-induced thrombocytopenia (HIT) type II: monitor platelet counts regularly; discontinue if HIT suspected","Risk of hemorrhage: use with caution in patients with bleeding disorders, recent surgery, or concurrent antiplatelet/anticoagulant therapy","Heparin resistance, especially in patients with antithrombin III deficiency or elevated factor VIII","Hypersensitivity reactions (urticaria, anaphylaxis)","Hyperkalemia due to suppression of aldosterone (especially with prolonged use, renal impairment, or concurrent potassium-sparing drugs)","Use preservative-free heparin for neonates and pregnant women (benzyl alcohol toxicity)","Osteoporosis with long-term use ( > 1 month)"] |
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| Fetal Monitoring | Monitor maternal platelet count for heparin-induced thrombocytopenia; activated partial thromboplastin time (aPTT) for anticoagulation effect; signs of bleeding (e.g., hematuria, bruising); fetal monitoring via ultrasound for growth and placental function. |
| Fertility Effects | No known adverse effects on fertility. Heparin is used in assisted reproductive technologies for thrombophilia without evidence of impairing fertility. |