HEPARIN SODIUM 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, inducing conformational change that accelerates its inhibition of thrombin (factor IIa), factor Xa, and other coagulation factors (IXa, XIa, XIIa).
| Metabolism | Primarily cleared by the reticuloendothelial system and liver (partial desulfation and depolymerization). Renal excretion of unchanged drug and metabolites. |
| Excretion | Renal (predominantly), with minor biliary/fecal elimination. Clearance is dose- and concentration-dependent due to saturable binding. |
| Half-life | 30-150 minutes (dose-dependent: 0.5-1.5 h at low doses, up to 2.5 h at high doses). Prolonged in hepatic or renal impairment. |
| Protein binding | Very high (>90%), primarily to antithrombin III, with minor binding to albumin and other plasma proteins. |
| Volume of Distribution | 0.05-0.07 L/kg (confined mainly to plasma); low Vd indicates limited tissue distribution. |
| Bioavailability | IV: 100%. SC: 20-30% (variable, dose-dependent). Not absorbed orally. |
| Onset of Action | IV: immediate (<1 min); SC: 20-60 min. |
| Duration of Action | IV: 2-4 h (APTT returns to baseline within 4-6 h after IV bolus); SC: 8-12 h (dose-dependent, may last up to 12 h). Effect may be prolonged in obesity, renal failure, or with high doses. |
Initial IV bolus of 80 units/kg followed by continuous IV infusion of 18 units/kg/hour; dose adjusted based on aPTT. Typical infusion range 10-30 units/kg/hour. Subcutaneous route: 5000 units every 8-12 hours for prophylaxis.
| Dosage form | INJECTABLE |
| Renal impairment | No standard dose adjustment for GFR; monitor aPTT and adjust accordingly. Use with caution in severe renal impairment (CrCl<30 mL/min) due to increased bleeding risk. |
| Liver impairment | No specific Child-Pugh based dosing adjustments; monitor aPTT closely due to altered coagulation factors. |
| Pediatric use | IV bolus: 75-100 units/kg over 10 minutes; maintenance: continuous IV infusion of 20-30 units/kg/hour adjusted to achieve target aPTT. Subcutaneous: 100 units/kg every 12 hours for prophylaxis. |
| Geriatric use | Elderly patients may have reduced heparin clearance and increased sensitivity; use lower initial doses (e.g., 50 units/kg bolus, 15 units/kg/hour infusion) and monitor aPTT frequently. |
| 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 high molecular weight and polarity; therefore, it is considered safe during breastfeeding. M/P ratio: Not applicable (undetectable in milk). |
| Teratogenic Risk | Heparin sodium does not cross the placenta and is not associated with teratogenicity. First trimester: No increased risk of congenital anomalies. Second trimester: Safe for use. Third trimester: No fetal harm. However, long-term use may cause maternal osteoporosis and bleeding risks. |
■ FDA Black Box Warning
HEPARIN-INDUCED THROMBOCYTOPENIA (HIT): Can cause HIT with or without thrombosis. Monitor platelet counts closely. Discontinue heparin if HIT is suspected. Risk of new thrombosis with HIT. Also, epidural/spinal hematoma risk in patients receiving anticoagulants undergoing neuraxial procedures: consider risk versus benefit before spinal intervention. Higher incidence in patients with renal impairment.
| Common Effects | bleeding |
| Serious Effects |
["History of heparin-induced thrombocytopenia (HIT) or heparin-induced thrombocytopenia with thrombosis (HITT)","Active major bleeding (e.g., intracranial, gastrointestinal, retroperitoneal)","Known hypersensitivity to heparin (including pork products)","Severe thrombocytopenia (platelet count <100,000/μL)","Inability to perform appropriate blood coagulation monitoring (e.g., aPTT)","Epidural or spinal anesthesia or lumbar puncture (relative contraindication) – risk of spinal hematoma"]
| Precautions | ["Risk of bleeding; monitor for signs of bleeding (e.g., hematuria, melena)","Heparin-induced thrombocytopenia (HIT) including thrombosis (HITT)","Epidural/spinal hematoma with neuraxial procedures","Hypersensitivity reactions (e.g., anaphylaxis)","Osteoporosis with long-term use (unfractionated heparin)","Hyperkalemia due to suppression of aldosterone","Use with caution in patients with renal impairment (increased bleeding risk)","Avoid intramuscular administration due to hematoma risk"] |
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| Fetal Monitoring | Monitor maternal activated partial thromboplastin time (aPTT) regularly (target 1.5-2.5 times control). Assess for signs of bleeding, heparin-induced thrombocytopenia (platelet count every 2-3 days during initiation), and bone density if prolonged use. Fetal monitoring via ultrasound for growth and placental health if indicated. |
| Fertility Effects | No known adverse effects on fertility. Heparin is not associated with impaired reproductive function in males or females. |
| Food/Dietary | No direct food interactions, but avoid excessive vitamin K-rich foods (e.g., leafy greens) if transitioning to warfarin. Alcohol may increase bleeding risk. |
| Clinical Pearls | Monitor aPTT closely; target 1.5-2.5 times control. Protamine sulfate is reversal agent. Use caution in renal impairment. Check platelets daily for HIT. Avoid IM injections. Use preservative-free formulation for neonates. |
| Patient Advice | Report any unusual bleeding or bruising immediately. · Avoid aspirin, NSAIDs, and other blood thinners unless prescribed. · Use soft toothbrush and electric razor to minimize bleeding risk. · Inform all healthcare providers that you are on heparin. · Do not stop taking abruptly; may require bridging with warfarin. |