Brand names of warfarin

  • Apo-Warfarin
  • Carfin
  • Coumadin
  • Panwarfarin
  • Sofarin
  • Taro-Warfarin
  • Warnerin

Warfarin is basically an anticoagulant medication that is taken orally. It works to restrain the production of factors that result in clotting and, in this way, puts off the formation of blood clots. Generally, when one is immobile for some period of time, it may lead to the formation of blood clots in the veins which are present in the lower extremities. Often, these blood clots may break away and stick in the blood vessels supplying to the lungs (a condition known as pulmonary embolism), resulting in the occurrence of chest pain, shortness of breath and also a grave or fatal shock. In addition, it is also possible that blood clots will take place within the heart's atria for the duration of atrial fibrillation as well as in the region of the artificial heart valves. Any of these blood clots may also disintegrate and cause obstruction in the blood vessels present in the brain, resulting in an embolic stroke accompanied by paralysis. Warfarin is a drug that effectively puts off blood clot formation. In addition, this medication is also vital in putting off the spread of blood clots that have formed earlier, as well as to diminish the chances of the occurrence of blood clot embolization to crucial organs, for instance, the brain and the lungs.

Things you need to tell your physician before taking warfarin

Before you start taking warfarin for the first time, you need to tell a few things to your physician as well as pharmacist. You should tell them whether you have any allergic reaction to this medication or any other drug. At the same time, you should be careful that you do not use two or additional medications containing warfarin simultaneously. If you are not certain about the contents of the medicines taken by you, ensure that you consult your physician or pharmacist whether they enclose warfarin or warfarin sodium.

Prior to undergoing treatment with warfarin, you should let your physician as well as pharmacist know about all the prescription and non-prescription drugs, dietary supplements and vitamins you are taking or intend to take. You should particularly talk to them if you are taking or plan to take any antibiotic; anti-cancer medications, aspirin or products containing aspirin and any other non-steroidal anti-inflammatory medications like ibuprofen (Motrin, Advil) plus naproxen (Naprosyn, Aleve); drugs to treat allergies, colds, cholesterol, diabetes, depression, digestive disorders (counting heartburn and ulcers), heart ailments, pain, thyroid diseases, gout and tuberculosis (TB); streptokinase; urokinase; ticlopidine; and/ or oral contraceptives (pills for birth control). In addition to the medications already named here, several other medicines too may interact with warfarin and, hence, ensure that you inform your physician about all other drugs you are already taking. It is advisable that you should not include any new medicine or discontinue any drug already existing in your medication list before consulting your physician.

People who plan to take warfarin for their condition should also inform their physician about their entire medical history, especially if they have ever suffered from or are suffering from diabetes or thyroid disorder. In addition, you also need to talk to your physician on whether you are suffering from any gastrointestinal ailment like diarrhea, sprue (an allergy to protein present in the grains attributable to diarrhea), or any infection. Also tell your physician if you are having any indwelling catheter (a flexible tube made from plastic which is positioned into the urinary bladder to enable the flow of urine).

Women intending to take warfarin ought to let their physician be aware if they are expecting, may sense that they are pregnant or planning to get pregnant. Women should be careful that they do not conceive while undergoing treatment with warfarin. In case a woman becomes pregnant during the course of treatment with this medication, she should contact her physician right away, as warfarin may possibly harm the still born. Before taking warfarin, women need to consult their physician regarding the success of birth control while using this medication. In addition, new mothers should tell their physician if they are breast feeding.

People who need to have a surgery, which includes any medical procedure or dental operation, should inform their surgeon or dentist that they are using warfarin in advance. In such cases, your physician is likely to advise you to discontinue warfarin prior to the operation or the procedure or alter the dose of this medication prior to any such action being taken. It is important that you should carefully abide by all the instructions of your physician and also keep all their appointments with the laboratories provided your physician asks you to take any blood test to determine the most suitable dosage of this medication for you.

People who consume alcoholic beverages or have been consuming it in heavy amounts should tell their physician about it. In such cases, your physician is very likely to ask you against taking warfarin. Most importantly, one ought to keep away from alcoholic beverages or consuming alcohol in any form while undergoing treatment with warfarin.

In case you have to take an immunization, for instance, a flu shot or any intramuscular injection, tell your physician or healthcare provider beforehand that you are using warfarin.


Warfarin is prescribed to put off as well as cure formation of blood clots in people having disorders related to the blood vessels, heart and lungs that might result in a stroke, heart attack or additional problems.

How to use warfarin

Warfarin is used orally together with or with no food, typically once every day. In addition, you may also use this anticoagulant medication as prescribed by your physician or recommended by any other healthcare expert. It is essential that you take this medication strictly as you have been instructed. Never take warfarin in excessive dose or more often than what has been prescribed. Also do not stop taking this medication all of a sudden or without consulting your physician.

The dosage of warfarin depends on the medical condition of the patient, the reports of laboratory examinations like INR and the receptiveness of the patient to the therapy. While you are undergoing treatment with warfarin your physician or healthcare provider will keep an eye on you to decide on the most appropriate dose of the medication for you. In order to obtain the maximum benefits of using warfarin you should take this medication on a regular basis. Moreover, it is advisable that you take warfarin at the same time daily, as it will help you to remember that you have to take this medication.

While undergoing treatment with warfarin is it crucial to have a balanced diet. In case you are endeavouring to lose those extra pounds, consult your physician prior to going on a diet. You should know that using food products containing cranberry also has the aptitude to affect the manner in which warfarin works. Therefore, it is advisable that you restrict your consumption of cranberry juice to just 16 oz or 480 ml daily. In addition, you should also limit the consumption of all other cranberry products.

How warfarin works

Warfarin works by obstructing the effect of vitamin K, an amalgam essential for forming blood clots.

Side effects

  • allergic reaction (breathing difficulty, wheezing, hives, or swelling of tongue, lips, and throat)
  • abnormal bleeding from nose, urinary tract, gastrointestinal tract or uterus
  • black vomit
  • bleeding into skin and soft tissue
  • bruises or purple marks on skin
  • excessive or unexpected menstrual bleeding
  • severe infection
Less common:

Possible interactions

Herbal medicines or minerals:
Generally, using herbal remedies in conjunction with warfarin is not recommended, as several herbal products are basically plant extracts having a variety of active amalgams, besides those that are listed on the product label and because many of these compounds are likely to act in the same manner as anticoagulant drugs.
The herbs you should particularly avoid using include alfalfa, anise, angelica root, devil's claw, borage seed oil, horse chestnut, pineapple (papain), ginkgo, ginger, garlic, willow bark, feverfew, clove oil, red clover, salvia root, cinchona root, turmeric and passionflower, as they have the aptitude to alter blood clotting. Hence, you should always keep away from therapeutic products containing the above mentioned herbs. It is advisable that if you are taking warfarin, you should consult your physician before you add any herbal product to your existing list of medications.
The effectiveness of warfarin diminishes in people who consume relatively excessive amounts of foods that are high in vitamin K content. Therefore, such people would require a comparatively higher dose of this medication. Some of the foods that contain high amount of vitamin K include bacon, cabbage, asparagus, beef liver, cauliflower, fish and all green leafy vegetables. There are a number of contradictory reports regarding consumption of food rich in vitamin C and resistance to warfarin. In addition, you should know that consuming foods having high vitamin E content in excess may augment the chances of hemorrhages.
People undergoing treatment with warfarin should restrict their alcohol consumption to just one drink every day. It may be noted that people who drink large amounts of alcoholic beverages on a regular basis and have a damaged liver may be very susceptible to anticoagulant medications. These people should take very small doses of the medication - much smaller compared to the normal dosage.
Tobacco smoking:
You should avoid smoking tobacco while taking anticoagulants. It may be noted that people who smoke may need comparatively higher doses of warfarin.


Unless you are suffering from any unusual hemorrhage, it is not advisable to discontinue warfarin all of a sudden or without consulting your physician. When you want to stop taking this medication seek the help of your physician regarding the decreasing the dose of this medication over a period of three to four weeks.

Storage instructions

Warfarin should always be stored at room temperature and in a place that is free from light and dampness. Never store this medication in your bathroom. In addition, it is important that you keep all your medications in a place that is beyond the reach of children as well as pets. Dispose of all medications whose expiry date has lapsed or medications that you do not require any longer in an appropriate and safe manner. If necessary seek the help of your pharmacist regarding the proper and safe disposal of such products.