HEPARIN SODIUM 10,000 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 binds to antithrombin III, inducing a conformational change that accelerates the inhibition of thrombin (factor IIa) and activated factor X (Xa), thereby preventing clot formation and extension.
| Metabolism | Primarily metabolized in the liver and reticuloendothelial system via desulfation and depolymerization; partially excreted unchanged in urine. |
| Excretion | Heparin is eliminated primarily via the reticuloendothelial system and renal excretion. Approximately 50% is excreted unchanged in urine via saturable zero-order kinetics, with the remainder metabolized to uroheparin and other inactive metabolites. Biliary/fecal excretion is negligible (<5%). |
| Half-life | Terminal elimination half-life is 1.5-2 hours (mean 1.6 h) at therapeutic doses, but is dose-dependent: 30-60 min after 25 U/kg, 1-2 h after 100-200 U/kg, and 2.5-5 h after 400-800 U/kg. Half-life is prolonged in hepatic or renal impairment. |
| Protein binding | Heparin is extensively bound to antithrombin III (ATIII) and other plasma proteins, with total protein binding approximately 90-95%. It also binds to heparin cofactor II, histidine-rich glycoprotein, platelet factor 4, and vitronectin. |
| Volume of Distribution | Volume of distribution (Vd) is approximately 0.05-0.07 L/kg (range 0.03-0.1 L/kg). This reflects limited extravascular distribution due to high molecular weight and negative charge, consistent with confinement to plasma volume. |
| Bioavailability | Subcutaneous: 70-90% bioavailability, with wide interindividual variability due to local blood flow and tissue binding. Intramuscular: not recommended due to risk of hematoma formation. No oral bioavailability. |
| Onset of Action | Intravenous: immediate (within 1-2 minutes). Subcutaneous: 20-60 minutes (mean 30 min) due to absorption delay. |
| Duration of Action | IV bolus: anticoagulant effect lasts 2-6 hours based on dose; continuous IV infusion maintains effect with steady-state. SC: duration is 8-12 hours; clinical monitoring (aPTT) is recommended to guide dosing. |
IV continuous infusion: initial bolus 80 units/kg, then maintenance 18 units/kg/hour; titrate to aPTT 1.5-2.5 times control. The solution HEPARIN SODIUM 10,000 UNITS IN DEXTROSE 5% is typically used for continuous infusion; dose should be adjusted based on patient weight and aPTT.
| Dosage form | INJECTABLE |
| Renal impairment | No specific GFR-based dose modification is required; however, accumulation may occur in severe renal impairment (CrCl <30 mL/min) due to decreased clearance. Monitor aPTT closely and reduce dose if aPTT is prolonged. |
| Liver impairment | Hepatic impairment (Child-Pugh A, B, C): Use with caution; reduced synthesis of coagulation factors may increase bleeding risk. No specific dose reduction guidelines are established; monitor aPTT and adjust accordingly. |
| Pediatric use | IV continuous infusion: initial bolus 75-100 units/kg, then maintenance 20 units/kg/hour for infants; 18 units/kg/hour for older children. Titrate to achieve aPTT 60-85 seconds or 1.5-2.5 times control. Use weight-based dosing; maximum concentration 1000 units/mL. |
| Geriatric use | Elderly patients (especially >70 years) may have altered pharmacokinetics and increased sensitivity; use lower initial bolus (50-75 units/kg) and lower maintenance infusion (15-18 units/kg/hour) with frequent aPTT monitoring. |
| 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. Considered safe during breastfeeding. M/P ratio not applicable (not detected). |
| Teratogenic Risk | Heparin does not cross the placenta. No increased risk of fetal malformations. First trimester: no known teratogenic effects. Second/third trimesters: no fetal harm reported. Risk of maternal hemorrhage may indirectly affect fetus. |
■ FDA Black Box Warning
Heparin is not intended for intramuscular injection; for subcutaneous administration, use a different concentration. Epidural or spinal hematomas may occur in patients anticoagulated with heparin who receive neuraxial anesthesia or undergo spinal puncture, resulting in long-term or permanent paralysis.
| Common Effects | bleeding |
| Serious Effects |
["History of heparin-induced thrombocytopenia (HIT)","Active major bleeding (except when due to disseminated intravascular coagulation)","Severe thrombocytopenia","Hypersensitivity to heparin or porcine products","Inability to perform adequate blood coagulation monitoring"]
| Precautions | Risk of hemorrhage; monitor platelets for heparin-induced thrombocytopenia (HIT); use with caution in patients with renal impairment, liver disease, or history of gastrointestinal bleeding; avoid in patients with active major bleeding or severe hypertension. |
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| Fetal Monitoring | Monitor maternal partial thromboplastin time (PTT) every 6-8 hours during initial dosing and daily once stable. Monitor platelet count every 2-3 days for heparin-induced thrombocytopenia. Observe for signs of bleeding (epistaxis, hematuria, bruising). Fetal surveillance as per gestational age; no specific fetal monitoring required for heparin. |
| Fertility Effects | No known adverse effects on fertility. Heparin does not interfere with ovulation, implantation, or spermatogenesis. |