Popular Drugs Catalogue



Chemical Name: WARFARIN (WAR-far-in)

Common uses
This medicine is an anticoagulant used to treat or prevent harmful blood clots that may occur in the veins (venous thrombosis) or lungs (pulmonary embolism), or with a type of abnormal heartbeat (such as atrial fibrillation), or following a heart valve replacement. This medicine is also used to reduce the risk of stroke and other problems in patients who have had a heart attack. It may also be used to treat or prevent other conditions as determined by your doctor.

Before using
Some medicines or medical conditions may interact with this medicine. INFORM YOUR DOCTOR OR PHARMACIST of all prescription and over-the-counter medicine that you are taking. ADDITIONAL MONITORING OF YOUR DOSE OR CONDITION may be needed if you are taking antibiotics, antifungal medicines (such as fluconazole, itraconazole, miconazole, voriconazole, terbinafine, and griseofulvin), rifampin, metronidazole, ribavirin, chloramphenicol, nonsteroidal anti-inflammatory medicines (such as ibuprofen, naproxen, indomethacin, piroxicam, mefenamic acid, rofecoxib, and celecoxib), acetaminophen, mesalamine, seizure medicines (such as carbamazepine, phenytoin, or phenobarbital), chloral hydrate, certain medicines for high cholesterol (such as gemfibrozil, atorvastatin, simvastatin, lovastatin, or cholestyramine), thyroid hormones (such as levothyroxine), certain asthma medicines (such as montelukast or zafirlukast), certain medicines for cancer, certain medicines for HIV infection (such as nevirapine or saquinavir), trazodone, aminoglutethimide, amiodarone, capecitabine, cimetidine, omeprazole, cisapride, disulfiram, male hormones, mifepristone, moricizine, quinine, quinidine, ropinirole, sulfinpyrazone, troglitazone, vitamin K, ticlopidine, or clopidogrel. DO NOT TAKE THIS MEDICINE with herbal teas. ADDITIONAL MONITORING OF YOUR DOSE OR CONDITION may be needed if you are taking other herbal products containing boldine, danshen, dong quai, fenugreek, ginseng, gingko biloba, quilinggao, or St. John's wort. DO NOT START OR STOP any medicine without doctor or pharmacist approval. Inform your doctor of any other medical conditions including any heart, lung, liver, kidney, or bladder problems; stomach or intestinal problems (such as ulcers); trauma or injuries; cancer; protein C deficiency; allergies; pregnancy; or breast-feeding. USE OF THIS MEDICINE IS NOT RECOMMENDED if you are planning or have recently had certain types of major surgery, surgery of the eyes or nervous system, spinal puncture or spinal anesthesia, or if you have a history of severe, untreated high blood pressure, certain heart conditions (such as inflammation or an infection of your heart), certain problems with your arteries or veins (such as an aneurysm), certain blood disorders or other bleeding problems, or in unsupervised patients who are unable to closely follow directions and routinely keep doctor and laboratory appointments. Contact your doctor or pharmacist if you have any questions or concerns about taking this medicine.

Follow the directions for using this medicine provided by your doctor. AVOID EATING LARGE AMOUNTS OF GRAPEFRUIT OR DRINKING LARGE AMOUNTS OF GRAPEFRUIT OR CRANBERRY JUICE while taking this medicine. STORE THIS MEDICINE at room temperature in a tightly-closed container, away from heat and light. Take this medicine regularly to receive the most benefit from it. Taking this medicine at the same time each day will help you to remember. CONTINUE TO TAKE THIS MEDICINE even if you feel well. Do not miss any doses. IF YOU MISS A DOSE OF THIS MEDICINE, take it as soon as possible. If it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. DO NOT take 2 doses at once.

DO NOT TAKE THIS MEDICINE if you have had an allergic reaction to it or are allergic to any ingredient in this product. DO NOT EXCEED THE RECOMMENDED DOSE without checking with your doctor. DO NOT STOP USING THIS MEDICINE without first checking with your doctor. Laboratory and/or medical tests, including blood clotting tests, may be performed to monitor your progress or to check for side effects. KEEP ALL DOCTOR AND LABORATORY APPOINTMENTS while you are using this medicine. BEFORE YOU HAVE ANY MEDICAL OR DENTAL TREATMENTS, EMERGENCY CARE, OR SURGERY, tell the doctor or dentist that you are using this medicine. THIS MEDICINE REDUCES BLOOD CLOTTING. To prevent bleeding, avoid any sports or other activities that may expose you to a risk of bruising or serious injury. DO NOT CHANGE BRANDS of this medicine without talking with your doctor or pharmacist. DO NOT CHANGE YOUR EATING HABITS, alcohol consumption, or activity level without checking with your doctor. A change in your diet, alcohol consumption, or activity level may lead to a change in the effects of your medicine. Foods that may change the effect of this medicine are those high in vitamin K, such as liver or green, leafy vegetables (lettuce, broccoli, cabbage, spinach, kale, or collard greens). BEFORE YOU BEGIN TAKING OR STOP TAKING ANY MEDICINE, either prescription or over-the-counter, check with your doctor or pharmacist. This includes vitamins, food or dietary supplements, or over-the-counter medicines such as aspirin, ibuprofen, acetaminophen, or cold medicines. IF YOU ARE ALREADY TAKING ASPIRIN for a heart or other condition, talk with your doctor about whether or not you should continue taking it with this medicine. WHILE YOU ARE USING THIS MEDICINE, brush your teeth carefully with a soft toothbrush, floss your teeth gently, and use caution when shaving. DO NOT BECOME OVERHEATED in hot weather as this may change the effect of this medicine. CAUTION IS ADVISED WHEN USING THIS MEDICINE IN THE ELDERLY because they may be more sensitive to the effects of the medicine. FOR WOMEN: DO NOT USE THIS MEDICINE if you are pregnant. IF YOU SUSPECT THAT YOU COULD BE PREGNANT, contact your doctor immediately. IT IS UNKNOWN IF THIS MEDICINE IS EXCRETED in breast milk. IF YOU ARE OR WILL BE BREAST-FEEDING while you are using this medicine, check with your doctor or pharmacist to discuss the risks to your baby.

Possible side effects
CHECK WITH YOUR DOCTOR AS SOON AS POSSIBLE if you experience diarrhea or any signs of illness, such as fever. CONTACT YOUR DOCTOR IMMEDIATELY if you experience any unusual pain, swelling, or discomfort; headache; dizziness; weakness; numbness; nosebleeds; excessive bleeding from cuts; bleeding from your gums while brushing your teeth; increased menstrual bleeding; unexplained vaginal bleeding; unusual bruising; red or dark brown urine; red or black, tarry stools; a purple, dark, or spotty discoloration of your toes; sudden or severe pain in your legs, feet, or toes; or any sores or ulcers on your skin. An allergic reaction to this medicine is unlikely, but seek immediate medical attention if it occurs. Symptoms of an allergic reaction include rash, itching, swelling, dizziness, or trouble breathing. If you notice other effects not listed above, contact your doctor, nurse, or pharmacist.

If you take too much
IF OVERDOSE IS SUSPECTED, contact your local poison control center or emergency room immediately. Symptoms of overdose may include abnormal or excessive bleeding or bruising and blood in your vomit, urine, or stools.

Additional information
Carry an identification card at all times that says you are taking this medicine. DO NOT SHARE THIS MEDICINE with others for whom it was not prescribed. DO NOT USE THIS MEDICINE for other health conditions. KEEP THIS MEDICINE out of the reach of children. IF YOU WILL BE USING THIS MEDICINE FOR AN EXTENDED PERIOD OF TIME, obtain refills before your supply runs out.