HEPARIN SODIUM 1,000 UNITS AND SODIUM CHLORIDE 0.9% IN PLASTIC CONTAINER
Clinical safety rating: safe
No significant drug interactions Can cause hypernatremia and fluid overload.
Heparin binds to antithrombin III, inducing a conformational change that accelerates the inactivation of thrombin (factor IIa) and activated factor X (Xa), thereby preventing thrombus formation and extension.
| Metabolism | Heparin is partially metabolized by the liver (desulfation) and cleared by the reticuloendothelial system. At high doses, renal excretion of unchanged drug occurs. Heparin does not undergo significant cytochrome P450 metabolism. |
| Excretion | Renal (primarily via reticuloendothelial system, desulfation, and degradation; small amount unchanged in urine <10%). Biliary/fecal excretion minor. |
| Half-life | Terminal elimination half-life 1–2 hours (dose-dependent; increases with higher doses due to saturable clearance). Clinical context: shorter half-life after IV bolus, prolonged in hepatic/renal impairment. |
| Protein binding | Extensive binding to antithrombin III (ATIII), heparin cofactor II, and other plasma proteins. Overall >90% bound; free fraction ~10%. |
| Volume of Distribution | 0.1–0.4 L/kg (small Vd, confined to plasma and extracellular fluid). |
| Bioavailability | SC: 20–30% (low and variable due to binding and degradation at injection site). IV: 100%. |
| Onset of Action | IV: immediate (within minutes); SC: 20–30 minutes (dose-dependent). |
| Duration of Action | IV: 2–4 hours (effect subsides rapidly after infusion stop). SC: 8–12 hours (prolonged with higher doses or in renal impairment). |
IV infusion: Initial bolus 80 units/kg, then 18 units/kg/h continuous IV infusion; titrate to aPTT 1.5-2.5 times control. Subcutaneous: 5,000 units every 8-12 hours.
| Dosage form | INJECTABLE |
| Renal impairment | GFR 30-60 mL/min: reduce dose by 20-30%; GFR <30 mL/min: avoid or reduce dose by 50% and monitor aPTT closely. |
| Liver impairment | Child-Pugh A: no adjustment; Child-Pugh B or C: consider dose reduction by 25-30% due to decreased antithrombin III levels. |
| Pediatric use | IV infusion: 75 units/kg bolus, then 20-28 units/kg/h continuous infusion; titrate to aPTT 1.5-2.5 times control. Subcutaneous: 100-150 units/kg every 12 hours. |
| Geriatric use | Elderly patients (≥70 years): lower initial bolus (50 units/kg) and infusion rate (15 units/kg/h); monitor aPTT closely due to increased bleeding risk. |
| 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 and polarity. M/P ratio not determined. Considered compatible with breastfeeding. |
| Teratogenic Risk | Heparin does not cross the placenta; no documented teratogenic risk. No increased risk of congenital anomalies reported. Pregnancy exposure is considered safe. |
■ FDA Black Box Warning
Heparin is not intended for intramuscular use due to risk of hematoma. For full prescribing information, consult the manufacturer's labeling. Spinal/epidural hematomas have occurred in patients anticoagulated with heparin who receive neuraxial anesthesia or spinal puncture, leading to long-term or permanent paralysis. Risk is increased by indwelling epidural catheters, concomitant use of other anticoagulants, antiplatelet agents, or thrombolytics, and a history of traumatic or repeated epidural/spinal punctures. Monitor patients for signs and symptoms of neurological impairment.
| Common Effects | fluid replacement |
| Serious Effects |
["Known hypersensitivity to heparin or pork products","Active major bleeding or conditions with high bleeding risk (e.g., hemophilia, thrombocytopenia)","History of heparin-induced thrombocytopenia (HIT) or heparin-induced thrombocytopenia with thrombosis (HITT)","Severe uncontrolled hypertension","Inability to perform regular coagulation monitoring","Suspected intracranial hemorrhage"]
| Precautions | ["Risk of bleeding: Monitor activated partial thromboplastin time (aPTT) regularly; avoid in patients with active bleeding or bleeding disorders.","Heparin-induced thrombocytopenia (HIT): Monitor platelet counts; discontinue if HIT is suspected and consider alternative anticoagulation.","Hypersensitivity reactions: May cause urticaria, angioedema, anaphylaxis; use caution in patients with history of heparin allergy.","Heparin resistance: May occur in patients with antithrombin III deficiency or elevated factor VIII.","Use with caution in patients with renal impairment, liver disease, or recent surgery/trauma."] |
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| Fetal Monitoring | Monitor aPTT (goal 1.5-2.5 times control), platelet count (heparin-induced thrombocytopenia), signs of bleeding, hemoglobin/hematocrit, fetal growth and well-being via ultrasound if long-term use. |
| Fertility Effects | No known adverse effects on fertility. Limited data, but heparin is not expected to impair reproductive function. |