HEPARIN SODIUM 5,000 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) via a unique pentasaccharide sequence, inducing a conformational change that accelerates ATIII-mediated inactivation of factor Xa and thrombin (factor IIa). This prevents fibrin formation and clot propagation. It also inhibits factors IXa, XIa, and XIIa.
| Metabolism | Heparin undergoes desulfation and partial depolymerization by reticuloendothelial system (liver, spleen) and is cleared by a combination of saturable (cellular uptake) and non-saturable (renal) mechanisms. Low molecular weight fractions are renally excreted. |
| Excretion | Renal: negligible; biliary/fecal: negligible; primarily cleared by hepatic depolymerization and reticuloendothelial system uptake. |
| Half-life | 30–150 minutes (intravenous), dose-dependent; at therapeutic doses ~60 minutes; prolonged in hepatic disease. |
| Protein binding | High, ~95%; binds to antithrombin III, albumin, lipoproteins, and fibrinogen. |
| Volume of Distribution | 0.04–0.07 L/kg; confined primarily to plasma volume. |
| Bioavailability | Subcutaneous: ~20–30%; intravenous: 100%; not absorbed orally. |
| Onset of Action | Intravenous: immediate; subcutaneous: 20–60 minutes. |
| Duration of Action | Intravenous: 2–6 hours (dose-dependent); subcutaneous: 8–12 hours; prolonged in renal impairment. |
| Molecular Weight | The average molecular weight of heparin ranges from 3,000 to 30,000 Da; pharmaceutical heparin typically has a mean molecular weight of around 15,000 Da. |
Continuous IV infusion: Initial bolus of 5,000 units, then 1,000 units/hour (25,000 units/24h) adjusted based on aPTT. Typical infusion rate 10-20 units/kg/hour.
| Dosage form | INJECTABLE |
| Renal impairment | No specific GFR-based dose adjustment required; heparin is not significantly renally cleared. Monitor aPTT closely in severe renal impairment (CrCl <30 mL/min) due to potential accumulation of antithrombin III-heparin complex. |
| Liver impairment | Child-Pugh A: No adjustment. Child-Pugh B and C: No specific dose adjustment, but increased monitoring due to potential coagulopathy and altered response. |
| Pediatric use | Initial bolus: 75-100 units/kg IV; maintenance infusion: 20-25 units/kg/hour for infants, 18-20 units/kg/hour for children, adjusted to target aPTT 60-85 seconds. |
| Geriatric use | Consider lower initial doses due to reduced clearance and increased bleeding risk; use actual body weight; monitor aPTT more frequently; typical starting infusion 10-15 units/kg/hour. |
| 1st trimester | Heparin does not cross the placenta and is not associated with fetal malformations; considered safe for maternal thromboembolic indications in pregnancy. |
| 2nd trimester | No increased risk of fetal harm; continue use if clinically indicated. Monitor for maternal bleeding complications. |
| 3rd trimester | Safe for use; does not cause fetal bleeding or teratogenicity. However, there is a risk of maternal hemorrhage, osteoporosis with prolonged use. |
Clinical note
Other drugs that affect hemostasis increase bleeding risk Can cause heparin-induced thrombocytopenia (HIT) and bleeding.
| FDA category | Human |
| Placental transfer | Heparin does not cross the placenta because of its high molecular weight and negative charge. |
| Breastfeeding |
■ FDA Black Box Warning
Heparin-induced thrombocytopenia (HIT). Spinal/epidural hematomas in patients receiving neuraxial anesthesia or spinal puncture, especially with concomitant anticoagulants or antiplatelet agents.
| Common Effects | bleeding |
| Serious Effects |
Hypersensitivity to heparin or pork productsActive major bleeding (e.g., intracranial, gastrointestinal, genitourinary)Severe thrombocytopenia (including heparin-induced thrombocytopenia, HIT)Inability to perform adequate blood coagulation monitoring (e.g., aPTT)Epidural or spinal anesthesia (risk of spinal hematoma)
| Precautions | Risk of heparin-induced thrombocytopenia (HIT) type II: monitor platelet counts regularly; discontinue if HIT suspected, Risk of hemorrhage: use with caution in patients with bleeding disorders, recent surgery, or concurrent antiplatelet/anticoagulant therapy, Heparin resistance, especially in patients with antithrombin III deficiency or elevated factor VIII, Hypersensitivity reactions (urticaria, anaphylaxis), Hyperkalemia due to suppression of aldosterone (especially with prolonged use, renal impairment, or concurrent potassium-sparing drugs), Use preservative-free heparin for neonates and pregnant women (benzyl alcohol toxicity), Osteoporosis with long-term use ( > 1 month) |
Loading safety data…
| Heparin is not excreted into breast milk due to its high molecular weight and poor oral bioavailability; considered compatible with breastfeeding. However, caution if the mother has bleeding disorders or if the infant has any coagulation abnormalities. |
| Lactation Rating | L1 (Safest) |
| Teratogenic Risk | Heparin does not cross the placenta; therefore, it is not associated with teratogenicity. No increased risk of congenital anomalies in first trimester. Second and third trimesters: safe for fetal development, but risk of maternal hemorrhage and placental abruption requires monitoring. |
| Fetal Monitoring | Monitor maternal platelet count for heparin-induced thrombocytopenia; activated partial thromboplastin time (aPTT) for anticoagulation effect; signs of bleeding (e.g., hematuria, bruising); fetal monitoring via ultrasound for growth and placental function. |
| Fertility Effects | No known adverse effects on fertility. Heparin is used in assisted reproductive technologies for thrombophilia without evidence of impairing fertility. |
| Food/Dietary | No specific food interactions. However, avoid excessive intake of vitamin K-rich foods (e.g., leafy greens) as they may counteract heparin's anticoagulant effect. Maintain a consistent diet regarding vitamin K intake. |
| Clinical Pearls | Heparin is a high-alert medication; verify dose and concentration before administration. Assess for signs of bleeding (e.g., bruising, hematuria) and monitor platelet counts regularly for heparin-induced thrombocytopenia (HIT). For weight-based dosing, use actual body weight. Do not administer intramuscularly due to risk of hematoma. Use preservative-free heparin in neonates. Flush line with normal saline before and after infusion to maintain patency. |
| Patient Advice | Report any unusual bleeding, bruising, or black/tarry stools immediately. · Avoid activities that may cause injury or bleeding (e.g., contact sports, shaving with a straight razor). · Use a soft toothbrush and electric razor to minimize bleeding risk. · Inform all healthcare providers (including dentists) that you are taking heparin. · Do not take any new medications (including over-the-counter or herbal products) without consulting your doctor. |