Drug interactions
Garlic + Heparin
Severity: Moderate
Garlic and Heparin: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Garlic supplements have antiplatelet activity and may add to the bleeding tendency of heparin. Clinical evidence is limited to case reports and pharmacodynamic data, and the effect with dietary amounts is likely small.
What this interaction means in plain words
Garlic and Heparin can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Garlic belongs to Gastrointestinal Tract; Heparin belongs to Cardiovascular.
Why it happens
Garlic constituents such as ajoene inhibit platelet aggregation, adding to heparin's anticoagulant effect.
What to do
Advise patients to avoid concentrated garlic supplements while on heparin. Monitor for bleeding and aPTT or anti-Xa levels if use continues.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Heparin
- Defibrotide + Heparin Contraindicated
- Heparin + Ketorolac Contraindicated
- Heparin + Oritavancin Contraindicated
- Acemetacin + Heparin Major
- Acetylsalicylic acid + Heparin Major
- Alteplase + Heparin Major
Other interactions of Garlic
- Garlic + Saquinavir Major
- Aceclofenac + Garlic Moderate
- Acemetacin + Garlic Moderate
- Aescin + Garlic Moderate
- Alteplase + Garlic Moderate
- Argatroban + Garlic Moderate
Frequently asked questions
Can I take Garlic with Heparin?
MediHelp rates the interaction as moderate. Garlic and Heparin can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Garlic supplements have antiplatelet activity and may add to the bleeding tendency of heparin. Clinical evidence is limited to case reports and pharmacodynamic data, and the effect with dietary amounts is likely small.
How serious is the interaction between Garlic and Heparin?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Advise patients to avoid concentrated garlic supplements while on heparin. Monitor for bleeding and aPTT or anti-Xa levels if use continues.
What other medicines interact with Heparin?
MediHelp also lists interactions of Heparin with, for example, Defibrotide, Ketorolac, Oritavancin. The full list is on the Heparin page.
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