HEPARIN SODIUM 25,000 UNITS IN DEXTROSE 5%
Clinical safety rating: safe
Other drugs that affect hemostasis increase bleeding risk Can cause heparin-induced thrombocytopenia (HIT) and bleeding.
Heparin sodium binds to antithrombin III (ATIII), inducing a conformational change that accelerates ATIII-mediated inactivation of factor Xa and thrombin (factor IIa), thereby inhibiting coagulation.
| Metabolism | Heparin is partially metabolized in the liver by depolymerization and desulfation via heparinase; also cleared by the reticuloendothelial system. Unchanged drug and metabolites are excreted in urine. |
| Excretion | Renal: negligible; primarily metabolized by the liver and reticuloendothelial system; small amount excreted unchanged in urine (<5%). Biliary/fecal: minimal. |
| Half-life | Terminal elimination half-life is approximately 1.5 hours (range 1–2 hours) after intravenous administration; dose-dependent: at therapeutic doses, half-life is about 1 hour; at higher doses, up to 2.5 hours. Clinical context: shorter half-life in pulmonary embolism, longer in renal impairment. |
| Protein binding | Very high: 95–98% bound; primarily to antithrombin III (ATIII) with some binding to albumin and other plasma proteins. |
| Volume of Distribution | 0.06–0.1 L/kg (limited to plasma volume; does not distribute into extravascular spaces). Clinical meaning: small Vd indicates heparin remains largely in the vascular compartment with minimal tissue penetration. |
| Bioavailability | Intravenous: 100%. Subcutaneous: approximately 30–40% (due to poor absorption of large molecule; higher doses may achieve up to 50% bioavailability). |
| Onset of Action | Intravenous: immediate (within minutes). Subcutaneous: 20–60 minutes (with 20,000–40,000 U/mL concentration, onset delayed to 1–2 hours). |
| Duration of Action | Intravenous: 2–6 hours (dose-dependent; effects wear off within 2–4 hours after bolus). Subcutaneous: 8–12 hours (with continuous infusion, duration is sustained). Clinical note: effects can be prolonged in renal failure or with higher doses. |
| Molecular Weight | 15000 |
Initial IV bolus of 5000 units, followed by continuous IV infusion at 1300 units/hour (typically 25,000 units in 500 mL D5W at 26 mL/hour) for therapeutic anticoagulation; dose titrated to aPTT 1.5-2.5 times control.
| Dosage form | INJECTABLE |
| Renal impairment | No specific dose adjustment required for GFR; however, heparin is eliminated renally, and accumulation may occur in severe renal impairment (CrCl <30 mL/min). Monitor aPTT closely and reduce infusion rate if prolonged. |
| Liver impairment | No specific dose adjustment based on Child-Pugh score; however, hepatic impairment may reduce anticoagulant effect due to decreased synthesis of coagulation factors. Monitor aPTT and adjust dose accordingly. |
| Pediatric use | Neonates and infants: initial IV bolus 75 units/kg, then continuous infusion 28 units/kg/hour (for age <1 year). Children >1 year: initial IV bolus 75 units/kg, then infusion 20 units/kg/hour. Titrate to aPTT 60-85 seconds. |
| Geriatric use | Elderly patients may have increased sensitivity to heparin due to reduced renal function and decreased clearance. Consider lower initial infusion rate (e.g., 1000 units/hour) and monitor aPTT more frequently to avoid bleeding. |
| 1st trimester | Heparin does not cross the placenta due to high molecular weight and negative charge. No evidence of teratogenicity in humans. Use if clinically indicated. |
| 2nd trimester | Heparin does not cross the placenta. No known fetal risk. Use for VTE prophylaxis or treatment as needed. |
| 3rd trimester | Heparin does not cross the placenta. Increased risk of maternal hemorrhage, especially during delivery. Monitor coagulation parameters. Use only if clearly needed. |
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 the placenta due to high molecular weight (12,000-15,000 Da) and negative charge. |
| Breastfeeding |
■ FDA Black Box Warning
Heparin is not intended for intramuscular injection due to risk of hematoma. Spinal or epidural hematomas can occur in patients anticoagulated with heparin who receive neuraxial anesthesia or spinal puncture, resulting in long-term or permanent paralysis. Risk is increased by use of indwelling epidural catheters, concomitant use of drugs affecting hemostasis, or a history of traumatic or repeated epidural/spinal punctures. Monitor patients for signs and symptoms of neurological impairment.
| Common Effects | bleeding |
| Serious Effects |
Active major bleedingHistory of heparin-induced thrombocytopenia (HIT)Severe thrombocytopeniaUncontrollable bleedingHypersensitivity to heparin or pork products
| Precautions | Hemorrhage: Major hemorrhage may occur; monitor coagulation tests and adjust dose. Use caution in conditions with increased bleeding risk., Thrombocytopenia: Heparin-induced thrombocytopenia (HIT) may occur; monitor platelet counts. Discontinue heparin if HIT is suspected., Heparin resistance: May occur in patients with antithrombin III deficiency or elevated factor VIII., Hyperkalemia: May suppress adrenal aldosterone secretion, leading to hyperkalemia; monitor potassium levels., Osteoporosis: Long-term use may increase risk of osteoporosis and fractures., Heparin use in pregnancy: Contains benzyl alcohol (preservative), which can cause gasping syndrome in neonates; use preservative-free formulation if possible. |
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| Heparin is not excreted into breast milk due to its high molecular weight and polarity, making it unlikely to affect the nursing infant. Compatible with breastfeeding. |
| Lactation Rating | L1 (Safe) |
| Teratogenic Risk | Heparin does not cross the placenta and is not teratogenic. No increased risk of fetal malformations reported in any trimester. Considered low risk for embryotoxicity. |
| Fetal Monitoring | Monitor maternal aPTT, platelet counts (risk of heparin-induced thrombocytopenia), signs of bleeding, osteoporosis with prolonged use. Fetal monitoring: ultrasound for growth and well-being if indicated by underlying condition. |
| Fertility Effects | No known adverse effects on fertility or reproduction. Heparin is not associated with hormonal alterations affecting conception. |
| Food/Dietary | No specific food interactions; however, vitamin K-rich foods (e.g., leafy greens) may affect clotting indirectly but are not contraindicated. Avoid excessive alcohol consumption as it may increase bleeding risk. |
| Clinical Pearls | For heparin sodium 25,000 units in D5W, verify infusion pump accuracy and tubing compatibility; use a dedicated line. In patients with heparin-induced thrombocytopenia (HIT), discontinue immediately and consider alternative anticoagulation. Monitor aPTT every 6 hours after initiation and dose adjustments; target aPTT 1.5-2.5 times control. Check platelet count at baseline and regularly; if HIT suspected, use anti-PF4/heparin ELISA. Avoid intramuscular injections during therapy. Protamine sulfate reverses effects; 1 mg neutralizes ~100 units of heparin. Note that dextrose 5% may affect blood glucose monitoring. |
| Patient Advice | This medication is a blood thinner given intravenously to prevent or treat blood clots. · Report any unusual bleeding, bruising, black or tarry stools, or blood in urine immediately. · You will need frequent blood tests (aPTT) to monitor the drug's effect. · Avoid aspirin, NSAIDs (e.g., ibuprofen, naproxen), and other blood thinners unless prescribed. · Inform all healthcare providers that you are on heparin before any procedures or surgeries. · Use a soft toothbrush and electric razor to minimize bleeding risk. · Do not change the infusion rate or stop the drip without doctor's orders. · If you experience severe headache, back pain, or signs of allergic reaction (rash, itching, swelling), seek help immediately. |