HEPARIN SODIUM 20,000 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), inducing a conformational change that accelerates ATIII-mediated inhibition of coagulation factors, primarily thrombin (factor IIa) and factor Xa, thereby preventing clot formation and propagation.
| Metabolism | Heparin is primarily cleared by the reticuloendothelial system and undergoes desulfation and depolymerization; a portion is excreted unchanged in urine. Metabolism is not dependent on cytochrome P450 enzymes. |
| Excretion | Renal: 40-60% as unchanged drug and metabolites; biliary/fecal: minimal (<10%) |
| Half-life | 1-2 hours (dose-dependent); extends to 2.5-4 hours with continuous infusion or renal impairment; clinical context: monitoring via aPTT required |
| Protein binding | High binding to antithrombin III (ATIII), albumin, and other proteins; effective binding essentially 100% via ATIII; unbound fraction <5% |
| Volume of Distribution | 0.05-0.07 L/kg (limited to plasma volume); does not cross placenta or blood-brain barrier |
| Bioavailability | Subcutaneous: 15-30% (variable; higher with low-molecular-weight heparin); Intravenous: 100% |
| Onset of Action | Intravenous: immediate; Subcutaneous: 20-60 minutes |
| Duration of Action | Intravenous: 2-4 hours (with bolus); Subcutaneous: 8-12 hours (dose-dependent) |
Intravenous: Initial bolus of 80 units/kg, followed by continuous infusion at 18 units/kg/hour. Titrate to achieve aPTT of 1.5-2.5 times control or anti-Xa level of 0.3-0.7 units/mL.
| Dosage form | INJECTABLE |
| Renal impairment | No specific GFR-based dose adjustment required; however, patients with severe renal impairment (CrCl <30 mL/min) may have altered clearance and require more frequent aPTT monitoring. |
| Liver impairment | Child-Pugh Class A and B: No adjustment. Child-Pugh Class C: Use with caution; monitor aPTT closely due to potential coagulopathy. |
| Pediatric use | Intravenous: Bolus of 75-100 units/kg over 10 minutes, followed by continuous infusion: Infants: 28 units/kg/hour; Children: 20 units/kg/hour; Adolescents: 18 units/kg/hour. Titrate to therapeutic aPTT. |
| Geriatric use | Elderly patients (≥65 years) may have reduced clearance; consider lower initial infusion rate (e.g., 15 units/kg/hour) and more frequent aPTT monitoring to avoid over-anticoagulation. |
| 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 its large molecular size and ionization, making it safe for breastfeeding. M/P ratio: Not applicable (not detectable in milk). |
| Teratogenic Risk | Heparin is a high-molecular-weight polysaccharide that does not cross the placenta, and there is no evidence of teratogenicity in humans. First trimester: No known fetal risk. Second trimester: No known fetal risk. Third trimester: No known fetal risk; however, use near delivery may increase maternal bleeding risk. |
■ FDA Black Box Warning
Heparin is not intended for intramuscular use. Fatal hemorrhagic events, including intracranial and retroperitoneal hemorrhage, have occurred. Monitor coagulation tests (aPTT) regularly. Spinal or epidural hematomas may occur in patients receiving neuraxial anesthesia or spinal puncture, leading to permanent paralysis. Risk is increased by concomitant use of other anticoagulants, traumatic puncture, or repeated epidural/spinal puncture.
| Common Effects | bleeding |
| Serious Effects |
["Hypersensitivity to heparin or pork products","History of heparin-induced thrombocytopenia (HIT) or heparin-induced thrombocytopenia with thrombosis (HITT)","Active major bleeding (e.g., intracranial, gastrointestinal, retroperitoneal)","Severe thrombocytopenia (platelet count <100,000/mcL or rapid decline)","Suspected or confirmed disseminated intravascular coagulation (DIC) unrelated to heparin therapy","Inability to perform appropriate coagulation monitoring (e.g., aPTT)"]
| Precautions | ["Hemorrhage: major bleeding risk; use with caution in conditions with increased bleeding risk (e.g., hemophilia, thrombocytopenia, recent surgery).","Heparin-induced thrombocytopenia (HIT): monitor platelet counts regularly; discontinue if HIT is suspected.","Hypersensitivity reactions: including urticaria, angioedema, anaphylaxis.","Hyperkalemia: due to suppression of aldosterone synthesis, especially in patients with renal impairment or diabetes.","Long-term use may cause osteoporosis and alopecia.","Benzyl alcohol preservative (if present) associated with 'gasping syndrome' in neonates."] |
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| Fetal Monitoring | Monitor maternal activated partial thromboplastin time (aPTT) to maintain therapeutic levels (typically 1.5-2.5 times control). Monitor platelet counts every 2-3 days for heparin-induced thrombocytopenia (HIT). Assess for signs of bleeding or thrombosis. Fetal monitoring as per standard obstetric care. |
| Fertility Effects | No known adverse effects on fertility in males or females. Heparin is not associated with hormonal disruption or impairment of reproductive function. |