Coumadin Side Effects

Coumadin (warfarin) is an anticoagulant (blood thinner). It reduces the formation of blood clots.

Coumadin is used to prevent heart attacks, strokes, and blood clots in veins and arteries.

Coumadin may also be used for purposes not listed in this medication guide.

You should not take Coumadin if you are allergic to warfarin, or if you have:

  • hemophilia or any bleeding disorder that is inherited or caused by disease;
  • a blood cell disorder such as anemia (lack of red blood cells) or a low level of platelets in your blood;
  • blood in your urine or stools, or if you have been coughing up blood;
  • an infection of the lining of your heart (also called bacterial endocarditis);
  • stomach or intestinal bleeding or ulcer;
  • recent head injury, aneurysm, or bleeding in the brain;
  • if you have recently had or will soon have any type of surgery (especially brain, spine, or eye surgery); or
  • if you undergo a spinal tap or receive spinal anesthesia (epidural).

You should not take Coumadin if you cannot be reliable in taking it because of alcoholism, psychiatric problems, dementia, or similar conditions.

Coumadin may cause you to bleed more easily, especially if you have:

  • a history of bleeding problems;
  • high blood pressure or severe heart disease;
  • kidney or liver disease;
  • cancer;
  • surgery or a medical emergency;
  • a disease affecting the blood vessels in your brain;
  • a history of stomach or intestinal bleeding;
  • if you are 65 or older; or
  • if you are severely ill or debilitated.

To make sure you can safely take Coumadin, tell your doctor if you have any of these other conditions:

  • celiac sprue (an intestinal disorder);
  • diabetes;
  • congestive heart failure;
  • overactive thyroid;
  • a connective tissue disorder such as Marfan Syndrome, Sjogren syndrome, scleroderma, rheumatoid arthritis, or lupus; or
  • if you have ever had low blood platelets after receiving heparin.

Follow your doctor’s instructions about taking Coumadin while you are pregnant. Coumadin can harm an unborn baby or cause birth defects. However, the benefits of preventing blood clots in certain women may outweigh any risks to the baby. Tell your doctor right away if you become pregnant during treatment. Use effective birth control while you are using Coumadin.

It is not known whether warfarin passes into breast milk or if it could harm a nursing baby. Do not use Coumadin without telling your doctor if you are breast-feeding a baby.

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

Stop using Coumadin 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 Coumadin 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.

Shares