What are warfarin tablets?
WARFARIN (Coumadin®) is an anticoagulant. Warfarin helps to treat or prevent clots in the veins, arteries, lungs, or heart. Warfarin stops clots from forming or getting bigger, and lets the body naturally dissolve the clots. Sometimes warfarin is called a blood thinner because you may bleed more easily while taking it; however, warfarin does not actually thin the blood.
What should I tell my health care provider before I take this medicine?
They need to know if you have any of these conditions:
• If you frequently drink alcohol-containing beverage
• blood disease, bleeding disorders, hemorrhage, hemophilia or aneurysm
• bowel disease, diverticulitis, or ulcers
• heart valve infection
• high blood pressure
• kidney disease
• liver disease
• protein or vitamin deficiency
• recent surgery
• thyroid problems
• an unusual or allergic reaction to warfarin, other medicines, foods, dyes, or preservatives
• pregnant or trying to get pregnant
How should I take this medicine?
Take warfarin tablets by mouth. Follow the directions on the prescription label. Warfarin is usually taken once a day. Swallow the tablets with a drink of water. Take your dose at the same time each day. Record your daily dose on a calendar when you take it. Do not take warfarin more often than directed.
Contact your pediatrician or health care professional regarding the use of this medicine in children. Special care may be needed.
What if I miss a dose?
Try not to miss doses. If you do miss a dose, take it as soon as you can that same day. If it is almost time for your next dose, take only that dose. Do not double doses, and do not take two doses in one day unless your prescriber or health care professional tells you to; this can increase the risk of bleeding. If you miss a dose, record the date of the missed dose and tell your prescriber or health care professional at your next visit. If you miss doses for two or more days, call your doctor for instructions.
What drug(s) may interact with warfarin?
Warfarin interacts with many other medicines; some are listed below:
• agents that dissolve blood clots
• agents that lower cholesterol
• antibiotics or medicines for treating bacterial, fungal or viral infections
• antiinflammatory drugs, NSAIDs, such as ibuprofen
• barbiturate medicines for inducing sleep or treating seizures
• cranberry juice and supplements containing cranberry extract
• female hormones, including contraceptive or birth control pills
• fish oil (omega-3 fatty acids) supplements
• herbal products such as danshen, garlic, ginkgo, ginseng, green tea, or kava kava
• influenza virus vaccine
• male hormones
• medicines for some types of cancer
• certain medicines for heart rhythm problems
• certain medicines for high blood pressure
• quinidine, quinine
• seizure or epilepsy medicine such as carbamazepine, phenytoin, and valproic acid
• thyroid medicine
• vitamin K (including vitamin, mineral, and food supplements that contain vitamin K)
Tell your prescriber or health care professional about all other medicines that you are taking, including non-prescription medicines, nutritional supplements, or herbal products. Also tell your prescriber or health care professional if you are a frequent user of drinks with caffeine or alcohol, if you smoke, or if you use illegal drugs. These may affect the way your medicine works. Check with your health care professional before stopping or starting any of your medicines.
What side effects might I notice from taking warfarin?
Side effects that you should report to your prescriber or health care professional as soon as possible:
• signs and symptoms of bleeding such as bloody or black, tarry stools, red or dark-brown urine, spitting up blood or brown material that looks like coffee grounds, red spots on the skin, unusual bruising or bleeding from the eye, gums, or nose
• back or stomach pain
• chest pain; fast or irregular heartbeat (palpitations)
• difficulty breathing or talking, wheezing
• fever or chills
• heavy menstrual bleeding or vaginal bleeding
• nausea, vomiting
• painful, blue, or purple toes
• prolonged bleeding from cuts
• skin rash, itching or skin damage
• unusual swelling or sudden weight gain
• unusual tiredness or weakness
• yellowing of skin or eyes
Side effects that usually do not require medical attention (report to your prescriber or health care professional if they continue or are bothersome):
• loss of appetite
• unusual hair loss
What should I watch for while taking warfarin?
Visit your prescriber or health care professional for regular checks on your progress. You will need to have your blood checked regularly to make sure you are getting the right dose of warfarin. The blood test that is used to monitor warfarin therapy is called the protime (PT) or INR. Your prescriber or health care professional will check your PT or INR and decide whether or not your dose of warfarin needs to be changed. When you first start warfarin, these tests are done frequently. Once the correct dose is determined and you take your medication properly, these tests can be done less often.
While you are taking warfarin, carry an identification card with your name, the name and dose of medicine(s) being used, and the name and phone number of your prescriber or health care professional or person to contact in an emergency.
You should discuss your diet with your prescriber or health care professional. Many foods contain high amounts of vitamin K, which can interfere with the effect of warfarin. Your prescriber or health care professional may want you to limit your intake of foods that contain vitamin K. Foods that have moderate to high amounts of vitamin K include brussel sprouts, kale, green tea, asparagus, avocado, broccoli, cabbage, cauliflower, collard greens, liver, soybean oil, soybeans, certain beans, mustard greens, peas (blackeyed peas, split peas, chick peas), turnip greens, parsley, green onions, spinach, and lettuce.
Warfarin can cause birth defects or bleeding in an unborn child. Women of childbearing age should use effective contraception while receiving warfarin therapy. If a woman becomes pregnant while taking warfarin, she should discuss the potential risks and her options with her health care professional.
Do not change brands of warfarin without talking to your prescriber or health care professional. Also, always check the color of your medicine when you get a new prescription. If you notice a change in the color of your warfarin tablet, check with your pharmacist or health care professional to make sure you received the correct medicine.
Alcohol can affect the way warfarin works. Ask your prescriber or health care professional how much, if any, alcohol you may consume.
Do not take any over-the-counter medicines without first talking to your prescriber or health care professional. Do not take any aspirin or aspirin-containing products, ibuprofen (Motrin®, Advil®, or Nuprin®) naprosyn (Aleve®), ketoprofen (Orudis-KT®) or other medicines known as nonsteroidal anti-inflammatory agents without talking to your prescriber or health care professional first.
Be careful to avoid sports and activities that might cause injury while you are using warfarin. Severe falls or injuries can cause unseen bleeding. Be careful when using sharp tools or knives. Consider using an electric razor. Take special care brushing or flossing your teeth. Report any injuries, bruising, or red spots on the skin to your prescriber or health care professional.
If you have an illness that causes vomiting, diarrhea, or fever for more than a few days, contact your doctor. Also check with your doctor if you are unable to eat for several days. These problems can change the effect of warfarin.
Even after you stop taking warfarin, it takes several days before your body recovers its normal ability to clot blood. Ask your prescriber or health care professional how long you need to be cautious. If you are going to have surgery or dental work, tell your prescriber or health care professional that you have been taking warfarin.
Where can I keep my medicine?
Keep out of the reach of children in a container that small children cannot open.