1 What is Coumadin?

Brand: Coumadin

Generic: Warfarin

Brand name: 


Since warfarin is a vitamin K antagonist, it is most commonly used to treat and prevent the formation of blood clots like in the cases of Venous thrombosis and Pulmonary embolism.

It is also indicated for the treatment and prophylaxis of thromboembolic complications that can occur with atrial fibrillation and/or cardiac valve replacement. It can also be prescribed to reduce the risk of death, as well as decrease the recurrence of myocardial infarctions and thromboembolic events.

Warfarin is to be administered by or under the supervision of a physician.

It is usually sold in powder form for reconstitution.

2 What to Know Before Using

Before using warfarin injection, you and your physician need to weigh the risks and benefits involved. Several factors need to be considered. Your primary care physician may assess you for any allergies to Warfarin or any of its ingredients.

Also, inform your doctor if you have allergies to other medications, food, preservatives, and/or animals.

The effects of Warfarin in pediatric patients have not been studied enough to establish safety and efficacy.

Although studies have shown that there are no age-related factors that hinder the efficacy of Warfarin in geriatric patients, its use should be closely monitored especially in those who are at risk of hemorrhage.

Warfarin has been found to cause fetal harm in pregnant women and is therefore contraindicated. Pregnancy status should be checked before starting treatment with this medication. Females should avoid getting pregnant while on Warfarin. Effective birth control methods must be utilized.

Studies have shown that Warfarin is not passed through breast milk. However, breastfed infants should still be monitored for any signs of bleeding or bruising. Several drugs may interact with Warfarin.

Amifampridine and Tamoxifen should not be prescribed simultaneously with Warfarin. Avoid medications that have CYP450 isozymes. These can affect how Warfarin is metabolized in the body. Drugs that may increase the risk of bleeding should also be stopped or avoided. Botanical products and foods may also interact with warfarin. Check with your doctor if you are on or plan to start/stop any herbal supplement. Consumption of cranberry juice, pomegranate, tobacco, black/green tea, high protein food, Noni Juice, and vitamin K-containing food should be avoided or decreased. Certain medical conditions can also change the efficacy and safety of warfarin use. These include bleeding problems, heart infection, recent spinal anesthesia, active stomach or intestinal ulcer, history of stroke, recent or upcoming surgery, recent or scheduled, threatened miscarriage, catheter insertion, congestive heart failure, heparin-induced deep venous thrombosis, diabetes, hypertension, kidney/liver disease, protein C deficiency, thrombocytopenia, and trauma.

3 Proper Usage

A nurse or medical professional should administer Warfarin since it is given via an intravenous route. The doctor may start you off with this and then switch you to an oral form depending on your condition and progress.

Dosage and timing are yet to be determined since these are highly individualized. Follow your doctor’s dietary instructions and talk to him/her before making any major dietary changes.

Warfarin is most effective when you consume the same amount of dietary Vitamin K.

Again, avoid eating too much vitamin K-containing foods.

4 Precautions To Take

Do not miss appointments with your physician. INR levels need to be monitored regularly when using warfarin. In this way, your doctor can prevent further complications or side effects.

If you have any upcoming surgical procedure or dental treatment, inform the concerned medical professionals that you are on warfarin therapy. Watch out for symptoms of infection like fever or diarrhea. Also, monitor your skin for any discoloration or pain since this medication can cause skin necrosis. Inform your physician immediately.

Warfarin can put you at risk of severe bleeding. Ask your physician to demonstrate ways to decrease this risk. Monitor for any signs and symptoms of bleeding such as unusual bruising, black/tarry stools, hematuria, blood in your stool, and/or pinpoint red spots on your skin. Use razors or other sharp objects with caution.

You can also ask your dentist or nurse about effective ways to maintain dental hygiene without the risk of injuring your mouth, tongue, or gums.

It is also recommended that you carry identification that indicates you are on Warfarin. Avoid strenuous activities or contact sports that could cause trauma or bruising.

Do not take any OTC medications or supplements without consulting your physician first.

5 Potential Side Effects

Aside from signs and symptoms of complications, you should also watch out for side effects. Some of them may go away without treatment but others may need immediate medical attention.

If you have:

  • Abdominal pain with cramping
  • Bleeding gums
  • Hematuria
  • Bloody stools
  • Confusion
  • Difficulty with breathing or swallowing
  • Excessive bruising
  • Paralysis
  • Peeling of the skin
  • Sweating
  • Unexplained swelling
  • And/or unusual tiredness or weakness

 Other effects that may not need medical attention include joint/muscle pain, cold intolerance, hair loss, and sluggishness. Talk with your doctor to get a more comprehensive list of what to expect when taking Warfarin.

Also, call your physician as soon as possible if you experience side effects that are not improving or getting worse.

6 Related Clinical Trials