About warfarin sodium
Vitamin K antagonist anticoagulant
Used for
- Prevents and treats blood clots
- Helps prevent stroke in atrial fibrillation
- Prevents clots in people with mechanical heart valves
Usual adult dose
Individualized; typically started at 2–5 mg once daily, then adjusted using blood tests (INR).
Usual dose in children
Individualized by age, weight, and INR; specialist dosing is required.
Common side effects
- Bleeding or bruising
- Nausea, vomiting, or diarrhea
- Rarely, skin or tissue damage
Important warnings
- Requires regular INR blood tests and dose adjustments.
- Serious bleeding can occur; seek urgent care for unusual or severe bleeding.
- Many medicines, supplements, and changes in vitamin K intake affect INR.
- Avoid during pregnancy, except in rare specialist-managed circumstances.
Pregnancy
Can cause miscarriage, birth defects, and fetal bleeding; generally avoided during pregnancy.
Breastfeeding
Generally compatible with breastfeeding; monitor the infant for unusual bruising or bleeding.
Interactions
- Aspirin and anti-inflammatory painkillers increase bleeding risk.
- Many antibiotics and antifungals can change INR.
- Amiodarone and several seizure medicines can alter warfarin effects.
- Vitamin K supplements and major diet changes can change INR.
AI-generated from general medical knowledge, not from this product's official leaflet. It may be incomplete or out of date. Not medical advice — ask a pharmacist or doctor before making any decision.