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Coumadin

Last reviewed on RxList: 8/25/2017
Coumadin Side Effects Center

Medical Editor: John P. Cunha, DO, FACOEP

Last reviewed on RxList 8/25/2017

Coumadin (warfarin) is a blood anticoagulant that inhibits the function of Vitamin K dependent coagulation used to inhibit the coagulation of blood to reduce or prevent the chance of developing heart attacks (myocardial infarctions), strokes, and venous and other blood clots (deep venous thromboses, pulmonary emboli and thrombi produced with atrial fibrillation). Coumadin is also used to treat these conditions if they develop. Coumadin is available as a generic. Common side effects of Coumadin include easy bruising and bleeding, nausea, vomiting, stomach pain, bloating, gas, or altered sense of taste.

Coumadin has a wide range of tablets: 2, 2.5, 3, 4, 5, 6, 7.5 and 10 mg tablets are available. An injectable form of the drug (5 mg) is also available. The dose of Coumadin is determined in each individual by administering a trial dose and ten measuring the patient's INR (International Normalized Ratio), a lab test that is standardized by the WHO (world Health Organization) and recognized worldwide. Therapeutic ranges for this test are between 2.0 to 3.0 when a patient is taking Coumadin. INR levels below 2 may allow easier blood clotting to occur while levels above 3 may cause excessive tendency for the patient to bleed. Coumadin may interact with other medications to prevent blood clots, antibiotics, antifungals, sulfa drugs, medicines to treat tuberculosis, antidepressants, herbal (botanical) products (including coenzyme Q10, cranberry, echinacea, garlic, ginkgo biloba, ginseng, goldenseal, or St. John's wort), secobarbital, barbiturates, seizure medications, and other drugs. Tell your doctor all medications and supplements you use. Pregnant women should not be given Coumadin; lactating women may need to be closely monitored and their breastfed infants should have their INR checked, according to some investigators. Although Coumadin has been used in pediatric patients to prevent clot formations, children under 18 have not been well studied with this drug and some investigators suggest achieving stable INR levels seems more difficult in the pediatric population.

Our Coumadin Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Coumadin Consumer Information

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Stop using warfarin and call your doctor at once if you have a serious side effect such as:

  • pain, swelling, hot or cold feeling, skin changes, or discoloration anywhere on your body;
  • sudden and severe leg or foot pain, foot ulcer, purple toes or fingers;
  • sudden headache, dizziness, or weakness;
  • unusual bleeding (nose, mouth, vagina, or rectum), bleeding from wounds or needle injections, any bleeding that will not stop;
  • easy bruising, purple or red pinpoint spots under your skin;
  • blood in your urine, black or bloody stools, coughing up blood or vomit that looks like coffee grounds;
  • pale skin, feeling light-headed or short of breath, rapid heart rate, trouble concentrating;
  • dark urine, jaundice (yellowing of the skin or eyes);
  • pain in your stomach, back, or sides;
  • urinating less than usual or not at all;
  • numbness or muscle weakness; or
  • any illness with diarrhea, fever, chills, body aches, or flu symptoms.

Less serious side effects may include:

  • nausea, vomiting, mild stomach pain;
  • bloating, gas; or
  • altered sense of taste.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Read the entire detailed patient monograph for Coumadin (Warfarin Sodium)

Coumadin Professional Information

SIDE EFFECTS

The following serious adverse reactions to COUMADIN are discussed in greater detail in other sections of the labeling:

Other adverse reactions to COUMADIN include:

Read the entire FDA prescribing information for Coumadin (Warfarin Sodium)

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