• Basic Info
• Clinical Info

What is this medicine?

WARFARIN (WAR far in) is an anticoagulant. It is used to treat or prevent clots in the veins, arteries, lungs, or heart.

This medicine may be used for other purposes; ask your health care provider or pharmacist if you have questions.

What should I tell my health care provider before I take this medicine?

They need to know if you have any of these conditions:

• alcoholism
• anemia
• blood disease, bleeding disorders, hemorrhage, hemophilia or aneurysm
• bowel disease, diverticulitis, or ulcers
• cancer
• diabetes
• heart disease
• heart valve infection
• high blood pressure
• history of bleeding in the gastrointestinal tract
• history of stroke or other brain injury or disease
• kidney or liver disease
• older than 65 years
• protein or vitamin deficiency
• psychosis or dementia
• recent surgery or injury
• an unusual or allergic reaction to warfarin, other medicines, foods, dyes, or preservatives
• pregnant or trying to get pregnant
• breast-feeding

How should I use this medicine?

Take this medicine by mouth with a glass of water. Follow the directions on the prescription label. You can take this medicine with or without food. Take your medicine at the same time each day. Do not take it more often than directed. Do not stop taking except on the advice of your doctor or health care professional.

A special MedGuide will be given to you by the pharmacist with each prescription and refill. Be sure to read this information carefully each time.

Talk to your pediatrician regarding the use of this medicine in children. Special care may be needed.

Overdosage: If you think you have taken too much of this medicine contact a poison control center or emergency room at once.
NOTE: This medicine is only for you. Do not share this medicine with others.

What if I miss a dose?

It is important not to miss a dose. If you miss a dose, call your healthcare provider. Take the dose as soon as possible on the same day. If it is almost time for your next dose, take only that dose. Do not take double or extra doses to make up for a missed dose.

What may interact with this medicine?

Do not take this medicine with any of the following medications:

• agents that prevent or dissolve blood clots
• aspirin or other salicylates
• danshen
• dextrothyroxine
• mifepristone
• St. John's Wort
• red yeast rice

This medicine may also interact with the following medications:

• acetaminophen
• agents that lower cholesterol
• alcohol
• allopurinol
• amiodarone
• antibiotics or medicines for treating bacterial, fungal or viral infections
• azathioprine
• barbiturate medicines for inducing sleep or treating seizures
• certain medicines for diabetes
• certain medicines for heart rhythm problems
• certain medicines for high blood pressure
• chloral hydrate
• cisapride
• disulfiram
• female hormones, including contraceptive or birth control pills
• general anesthetics
• herbal or dietary products like cranberry, garlic, ginkgo, ginseng, green tea, or kava kava
• influenza virus vaccine
• male hormones
• medicines for mental depression or psychosis
• medicines for some types of cancer
• medicines for stomach problems
• methylphenidate
• NSAIDs, medicines for pain and inflammation, like ibuprofen or naproxen
• propoxyphene
• quinidine, quinine
• raloxifene
• seizure or epilepsy medicine like carbamazepine, phenytoin, and valproic acid
• steroids like cortisone and prednisone
• tamoxifen
• thyroid medicine
• tramadol
• vitamin c, vitamin e, and vitamin K
• zafirlukast
• zileuton

This list may not describe all possible interactions. Give your health care provider a list of all the medicines, herbs, non-prescription drugs, or dietary supplements you use. Also tell them if you smoke, drink alcohol, or use illegal drugs. Some items may interact with your medicine.

Last Updated: October 20, 2009