Articles

Warfarin side effects: Watch for interactions

Warfarin side effects that require immediate medical attention

  • Severe bleeding, including heavier than normal menstrual bleeding
  • Red or brown urine
  • Black or bloody stool
  • Severe headache or stomach pain
  • Joint pain, discomfort or swelling, especially after an injury
  • Vomiting of blood or material that looks like coffee grounds
  • Coughing up blood
  • Bruising that develops without an injury you remember
  • Dizziness or weakness
  • Vision changes

Rarely, warfarin can cause the death of skin tissue (necrosis). This complication occurs most often three to eight days after you start taking warfarin. If you notice any sores, changes in skin color or temperature, or severe pain on your skin, seek immediate medical care.