Pronunciation:

WAR-far-in

Brand Names:

• Coumadin

Dosage Forms:

• Powder for Solution

Warnings:

Warfarin sodium can cause major or fatal bleeding. Bleeding is more likely to occur during the starting period and with a higher dose (resulting in a higher INR). Risk factors for bleeding include high intensity of anticoagulation (INR greater than 4.0), age 65 or greater, highly variable INRs, history of gastrointestinal bleeding, hypertension, cerebrovascular disease, serious heart disease, anemia, malignancy, trauma, renal insufficiency, concomitant drugs, and long duration of warfarin therapy. Regular monitoring of INR should be performed on all treated patients. Those at high risk of bleeding may benefit from more frequent INR monitoring, careful dose adjustment to desired INR, and a shorter duration of therapy. Patients should be instructed about prevention measures to minimize risk of bleeding and to report immediately to physicians signs and symptoms of bleeding .

Warfarin can cause major or fatal bleeding. Risk factors for bleeding include high intensity of anticoagulation (INR greater than 4.0), age 65 or greater, highly variable INRs, history of gastrointestinal bleeding, hypertension, cerebrovascular disease, serious heart disease, anemia, malignancy, trauma, renal insufficiency, concomitant drugs, and long duration of warfarin therapy. Regular monitoring of INR should be performed on all treated patients. Instruct patients about prevention measures to minimize risk of bleeding and to report immediately to physicians signs and symptoms of bleeding .

Warfarin sodium can cause major or fatal bleeding. Bleeding is more likely to occur during the starting period and with a higher dose (resulting in a higher INR). Risk factors for bleeding include high intensity of anticoagulation (INR greater than 4.0), age 65 or greater, highly variable INRs, history of gastrointestinal bleeding, hypertension, cerebrovascular disease, serious heart disease, anemia, malignancy, trauma, renal insufficiency, concomitant drugs, and long duration of warfarin therapy. Regular monitoring of INR should be performed on all treated patients. Those at high risk of bleeding may benefit from more frequent INR monitoring, careful dose adjustment to desired INR, and a shorter duration of therapy. Patients should be instructed about prevention measures to minimize risk of bleeding and to report immediately to physicians signs and symptoms of bleeding .

Warfarin can cause major or fatal bleeding. Risk factors for bleeding include high intensity of anticoagulation (INR greater than 4.0), age 65 or greater, highly variable INRs, history of gastrointestinal bleeding, hypertension, cerebrovascular disease, serious heart disease, anemia, malignancy, trauma, renal insufficiency, concomitant drugs, and long duration of warfarin therapy. Regular monitoring of INR should be performed on all treated patients. Instruct patients about prevention measures to minimize risk of bleeding and to report immediately to physicians signs and symptoms of bleeding .

Classifications:

Therapeutic—

Anticoagulant

Chemical—

Coumarin (class)

Uses of This Medicine:

Warfarin is an anticoagulant. It is used to decrease the clotting ability of the blood and to help prevent harmful clots from forming in the blood vessels. It is often used to prevent or treat deep venous thrombosis, a condition in which harmful blood clots form in the blood vessels of the legs. These blood clots can travel to the lungs and cause a condition called pulmonary embolism. Warfarin is also used to prevent or treat blood clots that are caused by certain heart conditions or open-heart surgery. It may be used after a heart attack to prevent blood clots from forming. Although it will not dissolve blood clots that have already formed, warfarin may keep the clots from becoming larger and causing more serious problems .

Warfarin is available only with your doctor's prescription .

Before Using This Medicine:

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:

Allergies—

Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Children—

Appropriate studies have not been performed on the relationship of age to the effects of warfarin in the pediatric population. Safety and efficacy have not been established .

Older adults—

Appropriate studies performed to date have not demonstrated geriatrics-specific problems that would limit the usefulness of warfarin in the elderly. However, elderly patients may require an adjustment in dose, especially those who are at risk of bleeding .

Pregnancy—

	Pregnancy Category	Explanation
All Trimesters	X	Studies in animals or pregnant women have demonstrated positive evidence of fetal abnormalities. This drug should not be used in women who are or may become pregnant because the risk clearly outweighs any possible benefit.

Breast-feeding—

Studies in women suggest that this medication poses minimal risk to the infant when used during breastfeeding.

Other medicines—

Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

• Abciximab
• Acenocoumarol
• Alteplase, Recombinant
• Ancrod
• Anisindione
• Anistreplase
• Antithrombin III Human
• Aprepitant
• Ardeparin
• Aspirin
• Bivalirudin
• Capecitabine
• Carboplatin
• Celecoxib
• Certoparin
• Chamomile
• Cilostazol
• Citalopram
• Clopidogrel
• Cranberry
• Cyclophosphamide
• Dalteparin
• Danaparoid
• Defibrotide
• Dermatan Sulfate
• Desvenlafaxine
• Dicumarol
• Doxorubicin
• Duloxetine
• Enoxaparin
• Eptifibatide
• Escitalopram
• Etoposide
• Etravirine
• Fenofibrate
• Fluorouracil
• Fluoxetine
• Fluvoxamine
• Fondaparinux
• Garlic
• Ginkgo
• Heparin
• Imatinib
• Ketoprofen
• Lamifiban
• Leflunomide
• Lycium
• Mechlorethamine
• Methotrexate
• Metronidazole
• Moxifloxacin
• Nadroparin
• Naproxen
• Nilotinib
• Noscapine
• Oxandrolone
• Papaya
• Parnaparin
• Paroxetine
• Pentosan Polysulfate Sodium
• Phenindione
• Phenprocoumon
• Procarbazine
• Proguanil
• Reteplase, Recombinant
• Reviparin
• Ropinirole
• Sertraline
• Sibrafiban
• Simvastatin
• Sitaxsentan
• St John's Wort
• Streptokinase
• Sulfamethoxazole
• Sulfisoxazole
• Tamoxifen
• Tan-Shen
• Tenecteplase
• Testosterone
• Tinzaparin
• Tirofiban
• Urokinase
• Venlafaxine
• Vincristine
• Vindesine
• Xemilofiban

Other interactions—

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Using this medicine with any of the following is usually not recommended, but may be unavoidable in some cases. If used together, your doctor may change the dose or how often you use this medicine, or give you special instructions about the use of food, alcohol, or tobacco.

• Cranberry Juice

Other medical problems—

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

• Alcohol abuse, history of or
• Mental disorders (e.g. psychosis or senility)—Patients with these conditions or those who cannot cooperate should not be given warfarin .

• Blood disease or bleeding problems or
• Heart infection or
• High blood pressure or
• Spinal anesthesia, recent or
• Stomach or intestinal ulcer (active) or
• Stroke or
• Surgery, recent or scheduled (e.g., surgery of the eye, brain, or spine) or
• Threatened miscarriage—Warfarin should not be used in patients with any of these conditions. The risk of bleeding from warfarin may be increased .

• Catheter insertion or
• Congestive heart failure or
• Deep venous thrombosis, heparin-induced or
• Diabetes mellitus (sugar diabetes) or
• Falls or blows to the body or head or
• Infection or
• Kidney disease or
• Liver disease or
• Major surgery, any type or
• Thrombocytopenia, heparin-induced—Use with caution. This medicine may increase your risk of having serious problems .

Proper Use of This Medicine:

A nurse or other trained health professional will give you this medicine. This medicine is given through a needle placed in one of your veins .

Precautions While Using This Medicine:

Your doctor will only give you a few doses of this medicine, and then you will be switched to an oral medicine that works the same way. If you have any concerns about this, talk to your doctor .

This medicine may increase your chance of bleeding. Check with your doctor right away if you notice any unusual bleeding or bruising; black, tarry stools; blood in the urine or stools; or pinpoint red spots on your skin. Avoid picking your nose. If you need to blow your nose, blow it gently .

Be careful when using a regular toothbrush, dental floss, or toothpick. Your medical doctor, dentist, or nurse may recommend other ways to clean your teeth and gums. Check with your medical doctor before having any dental work done .

Be careful not to cut yourself when you are using sharp objects, such as a safety razor or fingernail or toenail cutters. Avoid contact sports or other situations where bruising or injury could occur .

It is recommended that you carry identification that says you are using warfarin. If you have any questions about what kind of identification to carry, check with your doctor .

Side Effects of This Medicine:

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

Less common

Abdominal pain with cramping

bleeding gums

blood in urine

bloody stools

blurred vision

burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings

chest pain or discomfort

confusion

coughing up blood

difficulty with breathing or swallowing

dizziness, faintness, or lightheadedness when getting up from a lying or sitting position suddenly

excessive bruising

headache

increased menstrual flow or vaginal bleeding

nosebleeds

paralysis

peeling of skin

prolonged bleeding from cuts

red or black, tarry stools

red or dark brown urine

shortness of breath

sweating

unexplained swelling

unusual tiredness or weakness

Rare

Arm, back, or jaw pain

blue or purple toes

change in consciousness

chest tightness or heaviness

chills

clay-colored stools

diarrhea

dizziness

fainting or loss of consciousness

fast or irregular breathing

fast or irregular heartbeat

fever

hair loss or thinning of hair

itching

light-colored stools

loss of appetite

nausea and vomiting

pain in toes

pale skin

skin blisters

skin rash

small red or purple spots on skin

stomach pain

swelling of eyes or eyelids

tightness in chest and/or wheezing

troubled breathing with exertion

unpleasant breath odor

unusual bleeding or bruising

upper right abdominal pain

vomiting of blood

yellow eyes and skin

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Less common

Joint pain

muscle pain

Rare

Bloated

change in taste, or bad, unusual, or unpleasant (after) taste

cold intolerance

excess air or gas in stomach or intestines

full feeling

general feeling of discomfort or illness

hives or welts

lack or loss of strength

pain

passing gas

red, sore, or itching skin

sores, welting, or blisters

unusual drowsiness, dullness, or feeling of sluggishness

Incidence not known

Painful or prolonged erection of the penis

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.