heparin sodium at a glance
Medicine class
Anticoagulant, also called an antithrombotic.
Administration
Given by intravenous infusion, intravenous injection or subcutaneous injection, depending on the product and indication.
Important risk
Bleeding is the main complication. Heparin can also rarely cause immune-mediated thrombocytopenia with new thrombosis.
What is heparin sodium used for?
Licensed uses differ between formulations. Selected products are used for:
Preventing or treating deep-vein thrombosis and pulmonary embolism.
Treating unstable angina and acute peripheral arterial occlusion.
Preventing mural thrombosis following myocardial infarction.
Preventing clotting during extracorporeal circulation, haemodialysis or haemofiltration.
Maintaining intravenous catheter or cannula patency. Dedicated flush products are not for systemic anticoagulation.
How does heparin sodium work?
Heparin strengthens the action of anticoagulant proteins, particularly antithrombin. This inhibits clotting factors including thrombin and factor Xa, limiting clot formation and extension. It does not directly dissolve an existing clot.
heparin sodium preparations and strengths
Injection
Route: Parenteral
Strengths: 1000 units, 5000 units
How to take heparin sodium
Heparin is administered by injection or infusion because it is not reliably absorbed from the gut. It is usually given by healthcare professionals; only self-administer a subcutaneous product after specific training. A catheter-flush solution must only be used for its intended intravenous device.
Follow the technique demonstrated by your clinical team.
Do not inject heparin into a muscle because this can cause a haematoma.
Tell healthcare professionals that you receive heparin, particularly before surgery, spinal procedures or other injections.
Use only the exact formulation selected for the intended route and purpose.
heparin sodium side effects
Common or expected effects
- Injection-site bruising, discomfort, redness, nodules or eczema-like reactions.
- Minor bleeding, such as nosebleeds or easy bruising.
Get urgent medical advice
- Severe or internal bleeding, including blood in urine, black stools, vomiting blood or neurological symptoms.
- Heparin-induced thrombocytopenia, with a falling platelet count and possible new venous or arterial thrombosis.
- Severe hypersensitivity, including angioedema or anaphylaxis.
- Skin necrosis at an injection site.
- Hyperkalaemia, particularly with diabetes, kidney impairment, metabolic acidosis or potassium-raising treatment.
- Spinal or epidural haematoma associated with neuraxial procedures, potentially causing back pain, weakness, sensory changes or bladder or bowel dysfunction.
heparin sodium in pregnancy
Unfractionated heparin does not cross the placenta and can be used during pregnancy when clinically necessary. Pregnancy, labour and neuraxial anaesthesia require specialist planning. Selected formulations containing benzyl alcohol should be avoided in pregnancy, so a preservative-free product may be required.
heparin sodium interactions
Check all prescribed, over-the-counter and herbal products because combinations can alter bleeding risk or heparin response.
Antiplatelets, thrombolytics, other anticoagulants, salicylates and NSAIDs
May increase bleeding risk and require careful assessment and monitoring.
Intravenous diclofenac
Concomitant use is contraindicated for selected Wockhardt heparin injection and flush products.
Common questions about heparin sodium
Answers are fully visible for fast scanning and source review.
Is heparin sodium the same as low-molecular-weight heparin?
No. These products contain unfractionated heparin. Low-molecular-weight heparins have different properties and are not directly interchangeable.
Can heparin cause new blood clots?
Rarely, heparin-induced thrombocytopenia can lower platelets and trigger dangerous new venous or arterial clots.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.