Warfarin: Uses, Side Effects, and Drug Interactions
Brand names: Warfarin Sodium
# Warfarin: What You Need to Know Warfarin is a blood thinner medication that helps prevent blood clots from forming in your body. Doctors prescribe it to patients who have had a stroke, heart attack, or certain heart conditions, or who have blood clots in their legs or lungs. By making your blood less likely to clot, warfarin helps reduce the chance that dangerous clots will block blood vessels and cause serious health problems. However, warfarin is a powerful medicine that requires careful use and regular monitoring by your doctor. Because warfarin thins your blood, the biggest safety concern is bleeding. You need to be extra careful to avoid injuries, and you should tell your doctor right away if you notice unusual bruising, nosebleeds, or blood in your urine or stool. Many other medications can interact with warfarin and change how it works, including antibiotics, pain relievers, and herbal supplements, so always tell your doctor about everything you take. Your doctor will do regular blood tests to make sure warfarin is working properly for you. Never stop taking warfarin or change your dose without talking to your doctor first, as this could be dangerous.
Known Interactions (31)
Taking Warfarin with other medications?
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Check Now ↓Most Reported Side Effects (FAERS)
- INTERNATIONAL NORMALISED RATIO INCREASED10,373 reports
- DYSPNOEA8,469 reports
- DRUG INTERACTION6,314 reports
- FATIGUE6,206 reports
- NAUSEA5,974 reports
- DIARRHOEA5,961 reports
- DIZZINESS5,219 reports
- DRUG INEFFECTIVE5,166 reports
- FALL4,857 reports
- DEATH4,768 reports
Source: FDA Adverse Event Reporting System (FAERS). Voluntary reports do not establish causation.
Recent Recalls (2)
- Class II
CARDINAL HEALTHCARE · January 26, 2022
Warfarin Sodium Tablets, USP, 2.5 mg, 100 Tablets per bottle, Rx only, Manufactured For: Teva Pharmaceuticals, Parsippany, NJ 07054. NDC: 0093-1714-01CGMP Deviations: Products were exposed to temperatures outside of the products labeled storage conditions.
- Class II
CARDINAL HEALTHCARE · January 26, 2022
Warfarin Sodium Tablets, USP, 5 mg, 100 Tablets per bottle, Rx Only, Manufactured for: Teva Pharmaceuticals, Parsippany, NJ 07054. NDC: 0093-1721-01CGMP Deviations: Products were exposed to temperatures outside of the products labeled storage conditions.
Source: FDA (openFDA Drug Enforcement). Voluntary and mandated recalls affecting this drug.
Supplement Interactions (10)
These dietary supplements may interact with Warfarin. Always consult your healthcare provider.
- severest. john's wort
St. John's Wort induces CYP enzymes that metabolize warfarin faster, reducing its anticoagulant effect.
Avoid combination. INR monitoring required if used together.
- severevitamin k
Vitamin K directly counteracts warfarin's mechanism of action (inhibiting vitamin K-dependent clotting factors).
Maintain consistent vitamin K intake. Do not start or stop supplements without consulting your doctor.
- moderateginkgo biloba
Ginkgo has antiplatelet properties that may increase bleeding risk when combined with blood thinners.
Use with caution. Monitor for signs of bleeding.
- moderategarlic
Garlic supplements have antiplatelet properties that may enhance anticoagulant effects.
Inform your doctor if taking garlic supplements with blood thinners.
- moderateeicosapentaenoic acid
Omega-3 fatty acids have mild antiplatelet effects that may enhance anticoagulant activity.
Monitor for signs of bleeding. Inform your doctor.
- moderatedocosahexaenoic acid
Omega-3 fatty acids have mild antiplatelet effects that may enhance anticoagulant activity.
Monitor for signs of bleeding. Inform your doctor.
- moderatefish oil
Fish oil has mild antiplatelet effects that may enhance anticoagulant activity.
Monitor for signs of bleeding. Inform your doctor.
- moderatevitamin e
High-dose vitamin E (>400 IU) may inhibit platelet aggregation and enhance anticoagulant effects.
Avoid high-dose vitamin E with blood thinners.
- moderatecoenzyme q10
CoQ10 is structurally similar to vitamin K and may reduce warfarin's anticoagulant effect.
Monitor INR closely if starting or stopping CoQ10.
- moderateginseng
Ginseng may reduce warfarin's anticoagulant effect by unclear mechanisms.
Monitor INR when starting or stopping ginseng supplements.
Check interactions with Warfarin:
SafeCheck provides drug interaction information from FDA-approved product labeling (openFDA). This is for informational purposes only and is not medical advice. Always consult your healthcare provider before making medication decisions.