Effectiveness of Coumadin or Warfarin & Its Side Effects

Coumadin drug also known as warfarin is used in reducing blood clot formation. Coumadin or warfarin is used in prevention and treatment of blood clots in arteries and veins and this minimizes possible chances of heart attacks and stroke. This drug coumadin or warfarin is also utilized for other reasons not mentioned in this guide.

You need to take coumadin or warfarin if you are suffering from bleeding disorder, acute high blood pressure, bleeding in the stomach, presence of blood in stool, infection of the heart lining or before and after surgery and when in need of epidural or spinal tap.

Expectant women should not take coumadin or warfarin unless recommended by your physician. Please do not start taking coumadin or warfarin if you won’t be able to take it on a daily basis.

How Coumadin or Warfarin Works?

Coumadin or warfarin stops the generation of vitamin K-dependent clotting agents hence inhibiting blood thinning.

Effectiveness of Coumadin or Warfarin

Effectiveness of Coumadin or Warfarin

Coumadin or warfarin hinders the ability of the body to build blood clots and is also prescribed to treat and prevent pulmonary embolism and vein thrombosis.

Coumadin or warfarin effectively helps in discouraging blood clots from increasing as a result of valve replacement or atrial fibrillation. Coumadin or warfarin also effectively reduces death risk after a stroke or myocardial infarction caused by blood clotting.

  • Please note that foods which contain Vitamin K will interfere with coumadin or warfarin therapy. Eat normal balanced diet for consistent intake of vitamin K. Avoid eating a lot of foods that are rich in Vitamin K. Such foods include Kales, salad greens, broccoli, spinach, collards and other green leafy vegetables. Alcohol and cranberry juice will also affect coumadin or warfarin levels. Limit their consumption.
  • Coumadin or warfarin dosage is unique as per individual depending on their own treatment and their INR response to the drug. Factors such as weight, age, race, sex, comorbidities and concomitant medications affect dosage as well as genetic factors, for instance VKORC1 and CYP2C9 genotypes.
  • Initial low coumadin or warfarin dosage is recommended for people of Asian descent or frail and old people.
  • Initial high load dosage is discouraged for it can cause bleeding without providing rapid protection from blood clotting.
  • If you miss a dose, you can still take it within the 24hrs. If you forget to take the drug until the next day do not take double dose just forget about the missed dose.
  • You may stop your coumadin or warfarin dose if you are planning to undergo any surgery including dental care. Make sure you inform your surgeon early enough for advice and guidance.
  • Monitor yourself for any bleeding signs after taking coumadin or warfarin, including nose bleeding, presence of blood in urine or stool, gum bleeding, menstrual bleeding and seek medical advice immediately. Also reduce your bleeding risks; avoid falling or full sports contact and be careful when using a sharp object.
  • Strictly follow your dosage schedule. Always ask your physician before you take or stop taking any other medicine including over the counter drugs or herbal medicines. And ensure that your blood levels are monitored as advised.
  • Always carry or wear something that indicates you are taking coumadin or warfarin just in case of an emergency.
  • Inform your doctor if you suffer from an infection, fever or severe diarrhea for such concurrent illnesses may affect your response to coumadin or warfarin.
  • Jantoven and coumadin are both brands of warfarin. A slight difference in their formulation may imply that your body is responding differently to each of the brands. It is advisable for you to stick with one brand of warfarin to maintain stability of your INR levels.

The response and effectiveness of coumadin or warfarin are extraordinary. The slowing down of blood clots may be realized within 24hrs. However it can take between 72 and 96 hours for the full effect of this drug to be witnessed. One dose of coumadin or warfarin is effective between 2 to 5 days, however daily dosage is important to for maintaining constant blood levels. Effects accumulate with repeated dosage due to the time taken for vitamin K-depending clotting factors to renew. INR ranges vary depending with what is being treated and specific guidelines. Most guides targets INR of 2 to 3.

Period of treatment also varies from 90 days to lifelong considering the condition of the patient or until the dangers of embolism and thrombosis are mitigated.

The INR that reads 4 and above are equated with high risks of bleeding without any therapeutic advantage in most of the patients.

Side Effects of Coumadin or Warfarin

Seek immediate medical assistance in case of allergic reactions to coumadin or warfarin, like swelling of the face, breathing difficulties, hives and the swelling of the mouth, nose or eyes.

Coumadin or warfarin may cause fatal bleeding. Get immediate emergency help when you realize unusual bleeding that does not stop. One might also experience internal bleeding of the intestines or stomach. Inform you doctor if you cough blood, vomit blood or have black tools or presence of blood in the stool or urine.

Other side effects of coumadin or warfarin include:

  • Swellings, pains and cold or hot feeling.
  • Foot pain, purple fingers or toes, foot ulcers.
  • Sudden headache, fatigue and dizziness.
  • Easy bleeding or bruising of the nose or gums.
  • Bleeding of blood from injuries or injections that may not stop;
  • feeling light headedness, pale skin, short of breath, increase in heart rate, trouble focusing;
  • Yellowing of the eyes or skin.
  • No urination;
  • Muscle weakness or even numbness,
  • Painful back, stomach, sides.

Common side effects of coumadin or warfarin are:

  • Bloating, gas;
  • Mild stomach pains.
  • Lose of sense of tasting.
  • Vomiting
  • Nausea.
  • Serious and deadly bleeding.

It is difficult to determine whether coumadin or warfarin has been used in excess or less dosage. Therefore regular monitoring based on the international normalized ratio (INR) is required. However, monitoring depends on how a patient responds to a number of factors such as during the period of medication, dietary and disease.

Coumadin or warfarin cannot destroy existing blood clots. Likewise it cannot revive damaged tissues that have starved due to lack of oxygen. However it can hinder the progress of blood clotting as well as reducing the risks of artery and veins blockage due to the breaking off of blood clots.

Coumadin or warfarin is dangerous to babies, therefore expectant mothers or those planning to conceive should not take this drug.

Coumadin interacts with a number of drugs including heart medicines, some antibiotics, pain medication, oral contraceptives and acid suppressants. It also interacts with a number of botanicals which includes golden-seal, cranberry and grapefruit juices, echinacea, ginseng, ginko, St John’s wort and co-enzyme Q10.


Coumadin or warfarin is a very effective drug in reduction of blood clotting. However, there are factors that affect blood levels of coumadin or warfarin. These factors include ethnicity, diet, other medications and diseases. High levels of coumadin or warfarin in the blood can lead to serious and major bleeding complications.

Team PainAssist
Team PainAssist
Written, Edited or Reviewed By: Team PainAssist, Pain Assist Inc. This article does not provide medical advice. See disclaimer
Last Modified On:July 27, 2017

Recent Posts

Related Posts