Heparin Sodium
Pronunciation: (HEH-puh-rin).
- Generic name
- Heparin sodium
- Brand names
- Hepalean, Heparin Pfizer, Beparin, Monoject Prefill, Heparin Sodium, Monoparin
- Drug class
- Anticoagulant
Availability and supply rules vary by country
Trade names by country: United States · Canada
Australia: · Full directory
What Heparin sodium is and how it works
Uses, formulations, monitoring, and supply rules can differ by patient, product, and country. Follow the exact local product information and professional advice.
Mechanism of action: how Heparin sodium works
Heparin binds to antithrombin III, enhancing its inhibitory effect on activated clotting factors, particularly thrombin (factor IIa) and factor Xa. This leads to the inactivation of these factors and prevents the conversion of fibrinogen to fibrin, thereby inhibiting clot formation. Regulatory note: FDA labeling for heparin sodium injection carries a boxed warning against using it as a "catheter lock flush" product, because of fatal medication errors from mixing up vial concentrations (see serious warnings). (1) (2)
What Heparin sodium is used for
Prevention and treatment of venous thromboembolism (deep vein thrombosis and pulmonary embolism)
Prevention and treatment of venous thromboembolism (deep vein thrombosis and pulmonary embolism) (2)
Prevention of clotting in arterial and cardiac surgery
Prevention of clotting in arterial and cardiac surgery (2)
Prevention of clotting during hemodialysis and hemofiltration
Prevention of clotting during hemodialysis and hemofiltration (2)
Prevention of clotting in extracorporeal circulation (e.g., cardiopulmonary bypass)
Prevention of clotting in extracorporeal circulation (e.g., cardiopulmonary bypass) (2)
Before taking Heparin sodium
Do not take / not appropriate for
- active major bleeding, history of HIT, severe thrombocytopenia, and hypersensitivity to heparin or pork products. (Contraindication) (2)
Tell your clinician about
(2)How to take Heparin sodium
- General Instructions: Heparin is administered by injection, usually in a hospital or clinic. Follow your healthcare provider's instructions exactly.. Adult Dosing: Dosing varies based on indication. For DVT/PE prevention: 5,000 units subcutaneously every 8–12 hours. For treatment: initial IV bolus (e.g., 5,000 units), then continuous infusion adjusted by aPTT.. Pediatric Dosing: Dosing is weight-based and must be determined by a pediatric specialist. Close monitoring is essential.. Administration: Heparin is given by intravenous (IV) infusion or subcutaneous (SC) injection. Do not inject into muscle.. If Serious Side Effects Occur: Seek medical advice promptly; the clinician managing your care can advise on whether to continue or stop heparin.. Storage: Store at 20-25°C (68-77°F), away from light and moisture. Protect from freezing. Do not use if discolored or containing a precipitate. Keep out of reach of children.
- This page does not provide a dose calculator. Dosing must follow the prescriber, pharmacist, or product label.
Procedures and treatment changes
Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (2)
Missed dose
Heparin is administered by a healthcare professional, usually in a hospital or clinical setting, so a missed dose is uncommon. If you believe a scheduled dose was missed, contact your healthcare provider immediately for instructions. Do not take an extra dose to make up for it.
Overdose
Symptoms of overdose include excessive bleeding, bruising, or blood in urine/stool. Seek emergency medical help. Protamine sulfate is the antidote for heparin overdose. (2)
Side effects
Side effects and their urgency vary; report severe, persistent, or concerning symptoms to a healthcare professional.
Bleeding
Incidence: Reported in the clinician-authored database; frequency not established
Thrombocytopenia
Incidence: Reported in the clinician-authored database; frequency not established
Osteoporosis (long-term use)
Incidence: Reported in the clinician-authored database; frequency not established
Allergic reactions
Incidence: Reported in the clinician-authored database; frequency not established
Injection site reactions
Incidence: Reported in the clinician-authored database; frequency not established
Hair loss
Incidence: Reported in the clinician-authored database; frequency not established
Elevated liver enzymes
Incidence: Reported in the clinician-authored database; frequency not established
Serious warnings
BOXED WARNING (FDA) — serious
Symptoms: BOXED WARNING (FDA): Do not use heparin sodium injection as a "catheter lock flush" product. Heparin vials contain widely varying concentrations, including a highly concentrated 10,000 units/mL formulation. Fatal hemorrhages have occurred from medication errors caused by vial mix-ups. Every vial's label and concentration must be carefully verified before administration — this is a healthcare-facility procedural safeguard, not a patient action.
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (2)
Heparin can cause severe bleeding, which may be fatal — serious
Symptoms: Heparin can cause severe bleeding, which may be fatal. Risk of heparin-induced thrombocytopenia (HIT), a serious immune reaction. Monitor for signs of allergic reactions. Use caution in patients with recent surgery or trauma. Not for intramuscular use due to risk of hematoma.
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (2)
Contraindications recorded in the clinician database — serious
Symptoms: Contraindications recorded in the clinician database: active major bleeding, history of HIT, severe thrombocytopenia, and hypersensitivity to heparin or pork products. Use with caution in patients with bleeding disorders, recent surgery, peptic ulcer, severe hypertension, or hepatic/renal impairment. Independently confirmed additional contraindications: a history of thrombocytopenia associated with pentosan polysulfate (cross-reactivity risk), and inability to obtain regular coagulation-test monitoring at appropriate intervals.
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (2)
Interactions
| Medicine or test | Effect | Action |
|---|---|---|
| Recorded interactions | Heparin may interact with other anticoagulants (e.g., warfarin, DOACs), antiplatelet drugs (aspirin, clopidogrel), NSAIDs, and some herbal supplements (e.g., ginkgo, garlic). These combinations can increase bleeding risk. Always inform your healthcare provider about all medications and supplements you are taking. | (1) |
| Andexanet alfa | Andexanet alfa reduces heparin's anticoagulant efficacy. Concurrent use is generally avoided, or an alternative anticoagulant is used, under the treating clinician's direction. | (2) |
| Antithrombin III (human) | Antithrombin III enhances heparin's anticoagulant effect, which can raise bleeding risk; the treating clinician may reduce the heparin dose when the two are used together. | (2) |
Pregnancy, breastfeeding, kidney/liver function, age
Pregnancy
Published human studies have not shown increased maternal or fetal bleeding complications with heparin, and it does not readily cross the placenta; a preservative-free formulation is generally recommended in pregnancy. Animal studies at doses far above the maximum recommended human dose showed early embryo-fetal loss. Heparin use in pregnancy is decided case by case — anyone who is pregnant or planning pregnancy should discuss it with the prescribing clinician. (2)
Breastfeeding
Because of its large molecular weight, heparin itself is unlikely to pass into breast milk. Some multi-dose vials contain a benzyl alcohol preservative that may cross into milk, which is why a preservative-free formulation is generally recommended during breastfeeding — discuss the specific product with the prescribing clinician. (2)
Children
Frequency: Continuous infusion; bolus doses may be repeated as needed.. Weight Based: Initial bolus of 75-100 units/kg IV, followed by a continuous infusion of 20-30 units/kg/hour.. Max Daily Dose: Not established for pediatric use.. Max Single Dose: Not recommended for pediatric use.. Age Restrictions: Safety not established in children. A preservative-free formulation is required for neonates and infants; target laboratory monitoring (aPTT) is typically 60-85 seconds, adjusted by the treating specialist. (2)
Renal_impairment
The clinician record advises caution in hepatic or renal impairment, but no validated dose-adjustment protocol for reduced kidney or liver function was found in the independent literature reviewed. Dosing in organ impairment is individualized by the treating clinician using close coagulation monitoring rather than a fixed adjustment. (2)
Hepatic_impairment
The clinician record advises caution in hepatic or renal impairment, but no validated dose-adjustment protocol for reduced kidney or liver function was found in the independent literature reviewed. Dosing in organ impairment is individualized by the treating clinician using close coagulation monitoring rather than a fixed adjustment. (2)
Monitoring
(2)Storage
Store at 20-25°C (68-77°F), away from light and moisture. Protect from freezing. Use only if the solution is clear with an intact seal — do not use if discolored or if it contains a precipitate. Keep out of reach of children.
Study the drug class: Heparins and related parenteral anticoagulants
Professional information
Clinician-facing context only. This section does not replace current product labeling.
General — weight-based nomogram (common modern hospital protocol)
Indication: Prevention and treatment of venous thromboembolism (deep vein thrombosis and pulmonary embolism)
Dose summary: Initial bolus of 80 units/kg IV, followed by a continuous infusion of 18 units/kg/hour, titrated to aPTT.
Renal context: No validated fixed renal-dose-adjustment protocol was found in the independent literature reviewed; dosing is individualized by the treating clinician using close coagulation (aPTT) monitoring regardless of renal function. (1)
General — FDA label fixed-dose regimen (original approval-era dosing, still referenced)
Indication: Full-dose therapeutic anticoagulation
Dose summary: Deep SC: initial 333 units/kg, then 250 units/kg every 12 hours. Intermittent IV: initial 10,000 units, then 5,000-10,000 units every 4-6 hours. Continuous IV: initial 5,000 units, then 20,000-40,000 units per 24 hours. Low-dose prophylaxis: 5,000 units SC every 8-12 hours.
Renal context: No validated fixed renal-dose-adjustment protocol found; dosing is individualized with close coagulation monitoring. (2)
Frequently asked questions
What is heparin used for?
Heparin is used to prevent and treat blood clots in conditions like deep vein thrombosis (DVT), pulmonary embolism (PE), and during surgeries or dialysis to reduce clot risk.
How is heparin given?
Heparin is usually administered by injection, either intravenously (IV) or subcutaneously (under the skin), typically in a hospital or clinical setting.
What are the signs of heparin overdose?
Signs include excessive or uncontrolled bleeding, easy bruising, blood in urine or stool, and severe headache. Seek emergency help if these occur.
Can I take heparin if I am pregnant?
Heparin is considered safer than other anticoagulants during pregnancy, but should only be used under close medical supervision.
What should I do if I miss a dose?
Contact your healthcare provider immediately for instructions. Do not take an extra dose to make up for a missed one.
What is heparin-induced thrombocytopenia (HIT)?
HIT is a rare but serious immune reaction to heparin that causes a low platelet count and increases the risk of new blood clots. Immediate medical attention is required if suspected.
Are there foods or activities I should avoid while on heparin?
Avoid activities that may cause injury or bleeding. Discuss with your doctor before taking new medications or supplements, and limit alcohol intake.
What happens if I take too much Heparin?
Taking too much Heparin can lead to serious bleeding, which may manifest as unusual bruising, nosebleeds, blood in urine or stool, or prolonged bleeding from cuts. If you suspect an overdose, seek immediate emergency medical attention. Healthcare professionals can administer protamine sulfate, an antidote, to reverse the anticoagulant effects of Heparin.
Can I drink alcohol while taking Heparin?
It is generally advisable to limit or avoid alcohol consumption while taking Heparin. Alcohol can increase the risk of bleeding, a common side effect of anticoagulants. Combining alcohol with Heparin may further elevate this risk, potentially leading to serious hemorrhagic events. Always consult your healthcare provider regarding alcohol intake and your medication.
Is Heparin safe during pregnancy?
Heparin is generally considered a safer anticoagulant option during pregnancy compared to some other alternatives, as it does not readily cross the placenta. However, its use during pregnancy falls under a specific category, and the decision to prescribe it is made on a case-by-case basis after careful consideration of the benefits and risks. Always consult your doctor for personalized advice regarding Heparin use during pregnancy.
What is the mechanism of action of Heparin sodium?
Heparin binds to antithrombin III, enhancing its inhibitory effect on activated clotting factors, particularly thrombin (factor IIa) and factor Xa. This leads to the inactivation of these factors and prevents the conversion of fibrinogen to fibrin, thereby inhibiting clot formation. Regulatory note: FDA labeling for heparin sodium injection carries a boxed warning against using it as a "catheter lock flush" product, because of fatal medication errors from mixing up vial concentrations (see serious warnings). (1) (2)
What is the generic name of Heparin Sodium?
The generic name is Heparin sodium. It is sold under brand names including Hepalean, Heparin Pfizer, Beparin, Monoject Prefill, Heparin Sodium, Monoparin.
What class of drug is Heparin sodium?
Heparin Sodium is classed as: Anticoagulant.
References
- Heparin – clinician-authored medicine recordMedGuideGlobal · Global (internal) · accessed 2026-08-06 · source 1
- HEPARIN SODIUM Injection, USP – prescribing informationU.S. Food and Drug Administration · United States · accessed 2026-08-06 · source 2
- HEPARIN SODIUM INJECTION, SOLUTION [CARDINAL HEALTH 107, LLC] — US prescribing information (DailyMed SPL)U.S. National Library of Medicine (DailyMed) · US · accessed 2026-08-14 · source 3
- Heparin Sodium — FDA approval record (Drugs@FDA ANDA211007)U.S. Food and Drug Administration · US · accessed 2026-08-14 · source 4
- Heparin — RxNorm normalized drug concept (RXCUI 235473)U.S. National Library of Medicine (RxNorm) · US · accessed 2026-08-14 · source 5
Brand names by country
Single-ingredient Heparin sodium names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.
Priority countries
United States
- Heparin Sodium and Dextrose10000 [USP'U]00mL · hospira, inc.
Canada
- HEPARIN LOCK FLUSH
- HEPARIN LEO INJ
- HEPARIN SODIUM 25000UNIT/500ML IN 5% DEXTR INJ
- HEPARIN SODIUM 20000UNIT/500ML IN DEXT 5% INJ
- HEPARIN LEO