HEPARIN SODIUM 10,000 UNITS IN SODIUM CHLORIDE 0.45%
Clinical safety rating: safe
No significant drug interactions Can cause hypernatremia and fluid overload.
Heparin binds to antithrombin III, causing a conformational change that accelerates the inhibition of thrombin (factor IIa) and activated factor X (factor Xa), and to a lesser extent factors IXa, XIa, and XIIa, thereby preventing thrombus formation and extension.
| Metabolism | Heparin is metabolized by the liver and reticuloendothelial system. It is partially desulfated and depolymerized; some components are excreted unchanged in urine. Metabolism is dose-dependent and saturable at high doses. |
| Excretion | Renal (primarily via saturable mechanism; small amount metabolized by liver and reticuloendothelial system; no biliary/fecal elimination of significance) |
| Half-life | Mean 1-2 hours (dose-dependent: increases with dose due to saturable clearance; at 100 U/kg IV: ~1 hr; at 400 U/kg: ~2.5 hrs); clinical context: may be prolonged in hepatic/renal disease |
| Protein binding | Very high, ~95-98% (binds to antithrombin III, albumin, and other plasma proteins) |
| Volume of Distribution | 0.05-0.1 L/kg (confined to plasma volume; low Vd due to high protein binding and large molecular size) |
| Bioavailability | SC: 20-30% (variable based on injection site and depth); IV: 100% |
| Onset of Action | IV: immediate; SC: 20-30 minutes |
| Duration of Action | IV: 2-6 hours (dose-dependent); SC: 8-12 hours; clinical notes: effect can be reversed with protamine; monitoring aPTT required |
IV: Initial bolus of 80 units/kg, then 18 units/kg/hour continuous infusion. Adjust based on aPTT. Typical maintenance: 1300 units/hour for adult (70 kg).
| Dosage form | INJECTABLE |
| Renal impairment | No specific GFR-based dose adjustment required; monitor aPTT and adjust accordingly. Accumulation not significant due to large molecular weight and extensive protein binding. |
| Liver impairment | No specific Child-Pugh based modifications. Heparin clearance may be reduced in severe hepatic impairment; monitor coagulation parameters closely. |
| Pediatric use | IV: Bolus 75-100 units/kg over 10 minutes, then continuous infusion: Infants: 28 units/kg/hour; Children >1 year: 20 units/kg/hour; Adolescents: 18 units/kg/hour. Titrate to target aPTT (usually 60-85 seconds). |
| Geriatric use | Elderly patients (≥65 years) may have reduced heparin clearance; use lower initial infusion rates (e.g., 15 units/kg/hour) and monitor aPTT frequently to avoid over-anticoagulation. |
| 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. Compatible with breastfeeding. M/P ratio not applicable (not measurable). |
| Teratogenic Risk | Heparin does not cross the placenta and is not teratogenic. No increased risk of fetal malformations reported. Risk of hemorrhage at delivery. |
■ FDA Black Box Warning
Heparin is not intended for intramuscular use. There is an increased risk of bleeding complications. Monitor platelet counts regularly; heparin-induced thrombocytopenia (HIT) can occur. Use with caution in patients with history of HIT. Preservative-free heparin should be used in neonates and infants.
| Common Effects | fluid replacement |
| Serious Effects |
["Hypersensitivity to heparin or any component","History of heparin-induced thrombocytopenia (HIT) or HITTS","Active major bleeding (e.g., GI bleeding, intracranial hemorrhage)","Severe thrombocytopenia (platelet count <100,000/mm³)","Use of intramuscular injections while on heparin","Uncontrollable bleeding diathesis (e.g., hemophilia, severe liver disease)"]
| Precautions | ["Monitor for signs of bleeding (hematuria, melena, easy bruising, epistaxis, etc.)","Heparin-induced thrombocytopenia (HIT) and heparin-induced thrombocytopenia with thrombosis (HITTS): discontinue heparin immediately if HIT suspected","Epidural or spinal catheter use: risk of spinal or epidural hematoma with concurrent anticoagulants","Hyperkalemia due to aldosterone suppression (especially in elderly, diabetic, renally impaired)","Osteoporosis with prolonged use (>1 month)","Hypersensitivity reactions including urticaria, angioedema, anaphylaxis"] |
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| Fetal Monitoring | Monitor maternal platelet count (risk of heparin-induced thrombocytopenia), activated partial thromboplastin time (aPTT), signs of bleeding, and fetal surveillance (ultrasound for growth, nonstress test) if used in pregnancy. |
| Fertility Effects | No known adverse effects on fertility based on available data. |