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Heparin Side Effects

Medically reviewed by Last updated on Feb 21, 2024.

Applies to heparin: solution.

Serious side effects of Heparin

Along with its needed effects, heparin may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur while taking heparin:

Less common


After you stop using this medicine, it may still produce some side effects that need attention. During this period of time, Check with your doctor immediately if you notice the following side effects:

For Healthcare Professionals

Applies to heparin: injectable kit, injectable solution, intravenous solution.


The most common adverse reaction was hemorrhage.[Ref]


Postmarketing reports: Hemorrhage, retroperitoneal hemorrhage[Ref]


Very common (10% or more): Thrombocytopenia (up to 30%)

Frequency not reported: Plasma lipoprotein lipase increased

Postmarketing reports: Heparin resistance[Ref]


Frequency not reported: Conjunctivitis, cyanosis, tachypnea, feeling of oppression, angioneurotic edema, anaphylactic shock

Postmarketing reports: Chills, fever, urticaria, asthma, rhinitis, lacrimation, headache, nausea, vomiting, anaphylactoid reactions, shock, itching, burning[Ref]


Frequency not reported: Erythematous nodules, infiltrated and sometimes eczema-like plaques

Postmarketing reports: Local irritation, erythema, mild pain, hematoma, ulceration, histamine-like reactions, skin necrosis[Ref]


Frequency not reported: Allergic reactions, hypereosinophilia

Postmarketing reports: Heparin-induced thrombocytopenia, heparin-induced thrombocytopenia and thrombosis, generalized hypersensitivity reactions[Ref]


Frequency not reported: Hypoaldosteronism

Postmarketing reports: Adrenal hemorrhage, acute adrenal insufficiency, fatal adrenal hemorrhage, aldosterone synthesis suppressed[Ref]


Frequency not reported: Plasma potassium increased, hyperkalemia, metabolic acidosis

Postmarketing reports: Rebound hyperlipidemia[Ref]


Frequency not reported: Significant bone demineralization, spontaneous bone fracture

Postmarketing reports: Osteoporosis[Ref]


Frequency not reported: Ecchymoses

Postmarketing reports: Cutaneous necrosis, delayed transient alopecia[Ref]


Frequency not reported: Serum transaminases increased

Postmarketing reports: ALT elevated significantly, AST elevated significantly[Ref]


Postmarketing reports: Ovarian hemorrhage, priapism[Ref]


Frequency not reported: Renal function suppression[Ref]

Frequently asked questions


1. Product Information. Heparin Sodium (heparin). Lilly, Eli and Company. 2001;PROD.

2. Cerner Multum, Inc. UK Summary of Product Characteristics.

3. Cerner Multum, Inc. Australian Product Information.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.