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Principal Developer: B. Bartle Patient Information Medication Information for Patients taking Oral AnticoagulantsYou are being treated with oral anticoagulant medication for at least one of the following condition(s):
See brief descriptions of these conditions later on in this document. It is preferable that your anticoagulant dosage and blood tests be monitored by, preferably, one caregiver, who may be a physician, clinic nurse or pharmacist. In this document, healthcare provider refers to the one who normally manages your warfarin dosing and testing. WHAT IS AN ANTICOAGULANT? It is a drug to prevent and treat abnormal blood clotting. Anticoagulants are sometimes called "blood thinners", but this name is misleading. These drugs do not "thin the blood" they make your blood less likely to clot. WHY DO I NEED AN ORAL ANTICOAGULANT? You have either had a clotting event or you are felt to be at increased risk for a clotting event. An oral anticoagulant is prescribed to help stop abnormal blood clotting from occurring and thereby to prevent clotting events. HOW DOES AN ORAL ANTICOAGULANT WORK? It reduces the amount of circulating blood clotting factors produced in your liver. This makes your blood less likely to form abnormal clots. Thus, these drugs; 1) prevent abnormal clots from forming in blood vessels or your heart, or 2) stop existing blood clots from getting any larger. WHY ARE BLOOD CLOTS SO DANGEROUS? Abnormal blood clots can form in your arteries, veins, or heart. They are dangerous because they can prevent blood and oxygen from reaching vital organs and tissues; they can also break off and be carried through the blood stream . Blood clots can cause a heart attack or stroke if they lodge in blood vessels of the heart or brain, or pulmonary embolism if they lodge in the lungs. HOW DO I TAKE THE ORAL ANTICOAGULANT? In North America, almost all patients would be started on the oral anticoagulant, warfarin (Coumadin ®). Only if you have been thought to have experienced an abnormal reaction to warfarin, such as a skin rash, might you receive the alternative oral anticoagulant, nicoumalone (Sintrom ®). Warfarin is available as different strength tablets; it is generally recommended that you only be prescribed one strength of tablet at one time. Multiples or fractions of that tablet strength can be used to attain the proper dose for you. Warfarin is generally taken once daily and can be taken at any time of the day. If you are on other medications, warfarin can be taken at the same time as most of these other medications in order to simplify your drug regimen. On the day of the blood test (INR) to determine the appropriateness of the dose, it is best to withhold that day's dose of warfarin until you have received the results of the test. The dose of warfarin may vary from day-to-day in a week and from time-to-time over the year, so it is wise to have a warfarin calendar to record the dosage and the INR tests HOW LONG WILL I HAVE TO TAKE WARFARIN? New information about the appropriate length of time to be on warfarin is still being researched, especially for patients with a deep vein thrombosis or pulmonary embolism. Many people must take anticoagulant medication for the rest of their lives, while others only need to take it for 3-12 months. You should never stop taking this medication without first discussing it with your doctor. WHY DO I NEED BLOOD TESTS? Blood tests are required to establish the correct amount of warfarin you need in order to keep abnormal blood clots from forming and to reduce the risk of bleeding Anticoagulation is an extremely delicate process; if you take too much of the drug, you increase your risk of developing serious bleeding. If the dose is too low, you are at risk of (re)developing a stroke, heart attack or venous clot. Unlike most other medications, these blood tests must continue to be done as many factors affect your response to warfarin. A blood test result that is within the desired range is the most important aspect of warfarin therapy, not the number of milligrams of drug or number of tablets per day. Some patients required as little as 1mg per day while others require over 10mg per day to attain the right result. WHAT TYPE OF BLOOD TESTS DO I NEED TO HAVE? Your lab, or clinic will take small amount of blood to find out your prothrombin time(PT), which is roughly the amount of time it takes for your blood to clot. The PT is recorded as an INR(International Normalized Ratio) , a standardized way of measuring the PT. Patients not taking warfarin have an INR value of approximately 1; most patients on warfarin require an INR between 2.0 and 3.0. Patients with some types of mechanical heart valves require an INR of 2.5 to 3.5. An INR below the desired result may result in a new blood clot or stroke; an INR greater than 4 may put you at risk of having a serious bleeding episode. HOW OFTEN DO I NEED TO HAVE BLOOD TESTS? When you first start taking warfarin, you may need to undergo an INR test every few days or every week depending on the condition requiring the anticoagulant. Once your healthcare provider has determined an appropriate dosage, you may have to continue having the test once every 1-2 weeks for a few weeks. If these test results remain stable and in the desirable range, then tests every 4-5 weeks on a regular basis is appropriate. WILL MY TEST RESULTS CHANGE FROM TIME TO TIME? Yes, that is why the test must continue to be done while you are taking warfarin. In the beginning, your test results will change as your healthcare provider tries to determine the appropriate dose for you. After your correct dose has been determined initially, many factors, such as new illnesses, new medications, diet and activity level could affect your INR results. Forgetting to take your warfarin, especially within a day or two of your scheduled INR test can also affect the results. Tell your healthcare provider any new information regarding the above, especially if your INR test is too low or high. WHAT ARE THE DOs AND DON'Ts OF TAKING WARFARIN? HERE IS A LIST OF THINGS YOU SHOULD REMEMBER. DOs DO take your warfarin exactly as your healthcare provider tells you DO get your blood tested when you are supposed to. Use a calendar to record your INR result and warfarin doses until the next test DO tell your healthcare provider about all other medications you are taking. Also, talk to your healthcare provider BEFORE you change, start, or stop taking any other medicines or herbal products DO keep your eating habits and activities reasonably similar every day, because sudden changes can affect your INR DO tell your healthcare provider when you get sick or injured, get a cut that won't stop bleeding, or if you plan on becoming pregnant. DO keep warfarin (and all medicines) OUT OF THE REACH OF CHILDREN DO tell your doctor if you are planning on getting pregnant DO tell anyone giving you medical or dental care that you are taking warfarin DO refill your prescriptions according to your healthcare provider's instructions to avoid running out of warfarin. DO consider wearing a MEDICAL ALERT(or similar) bracelet . DO discuss with your doctor issues around pregnancy and immediately contact your treatment team if you wish to plan a pregnancy Do continue to take one or two alcoholic drinks (beer, glass of wine, shot or spirits) per day if this has been your habit. Do continue to eat green vegetables, especially broccoli, which have very beneficial health effects, however, try to eat roughly the same quantities daily. DON'Ts DO NOT take warfarin if you are pregnant or plan to get pregnant without contacting your doctor. DO NOT take or discontinue any other medicines without checking with your healthcare provider first. DO NOT make drastic changes in your diet, lifestyle or activities without first informing your healthcare provider DO NOT drink alcohol to excess- one or two drinks per day are permitted unless you have been told not to drink alcohol for other reasons. Avoid binge drinking Do not suddenly change your diet. YOU SHOULD REPORT: Any fall or injury to the head or back Fever and chills that last for more than 2 days Any vomiting, nausea or diarrhea for more than 2 days Repeated severe chest pain or shortness of breath Vomiting blood, passing blood by rectum, blood in the urine, nose bleeds that do not stop after 5-10 minutes of firm pressure, spontaneous large multiple bruises Any major change to your general health ANSWERS TO COMMONLY ASKED QUESTIONS? What should I do if I forget to take a warfarin pill? Warfarin has a fairly long effect so taking a dose late will not have any dramatic effect. If you forget to take your dose at the regularly scheduled time, take it when you remember at any time on that day. If it is the next day when you remember that you forgot to take yesterday's dose, it is safe to take both the forgotten dose and one for that day at once- ie: 2 doses for that day only. If you forget to take your warfarin for two or three days in a row,, DO NOT take all of the missed doses, but call your health care provider for instructions. Can I take other common drugs while I'm on warfarin? What if I have a headache or a 'cold'? It is generally best to check with your physician,pharmacist or clinic BEFORE starting any new medication on your own. However, if necessary, you can safely take 1 or at most 2 tablets of Aspirin ®, acetaminophen (Tylenol ®), or ibuprofen (Advil ®, Motrin ®). If you require longer treatment with any of these, you should call your physician , pharmacist or clinic. Presently, we know very little about the effects of herbal medications (remedies) on oral anticoagulation therapy-thus they should be treated as any new medication and an additional INR test should be obtained 4-5 days after starting the herbal medication. It is preferable to consult your healthcare provider before starting one of these products. What should I do if I cut myself or get injured? Generally, small cuts or abrasions will stop bleeding after applying a little longer direct pressure to the cut. Call your doctor immediately if you have a serious fall or hit your head. You may need to be examined by your doctor or at an Emergency Department. What should I do if I become pregnant while taking warfarin? Warfarin should not be taken if you are pregnant or are planning to become pregnant because oral anticoagulation medication can affect the development of the fetus. If you become pregnant while taking warfarin, you should stop it right away and contact your doctor. If therapy is required during pregnancy, you doctor can change your medication to an injectable heparin product to safely and effectively continue anticoagulation during the pregnancy. Can I travel while taking warfarin? Oral anticoagulation therapy should generally not affect any travel plans but try and tell your healthcare provider before you go; depending on how long you will be away, you may need an INR test before you leave or they may want to make arrangements with you to get a test while you're away . These latter test results are best discussed with your healthcare provider at home, not a practitioner at your destination site who may charge a fee for this service. BE SURE TO HAVE ENOUGH MEDICATION WITH YOU. Can I participate in sports or physical activities? It is better to ask your doctor before starting any new sports or activity, especially if there is a risk of you falling or being injured during the activity. If you play squash or racquetball, you should wear eye protection. Proper protective equipment is recommended for all sports. What should I watch for while taking warfarin? Here is a list of caution signals you should watch for. If you experience any of the following, notify your doctor right away. Your dose of warfarin may need to be adjusted.
Elderly patients are known to be more sensitive to the anti-coagulant effects of
warfarin and thus are known to experience more bleeding complications. HOW DO LIFESTYLE AND DIET AFFECT WARFARIN THERAPY? Physical Activities Patients taking oral anticoagulants can continue physical activities such as walking, swimming, cycling, and gardening. These and other similar activities are beneficial since they promote good blood circulation. However, you should probably avoid contact sports or other activities in which injuries are common. Diet Consume a standard healthy diet. Although certain foods in your diet contain the 'antidote' to warfarin, vitamin K, used to reverse the effect of too much warfarin, this is taken into account when determining your maintenance dose of warfarin. These foods, mainly green, leafy vegetables, can be eaten on a regular basis. If one of your INR readings is low, try to remember if you consumed an abnormally large amount of these foods just before the test. Your healthcare provider will need to know that so they don't make an unnecessary change in your dose of warfarin. Alcohol Patients on warfarin can safely have one or two alcoholic drinks( beer, glass of wine, shot of spirits) a day. Amounts of alcohol greater than this can cause the INR to go too high and be dangerous. DO NOT binge drink WHAT YOU SHOULD KNOW ABOUT YOUR CONDITION THAT REQUIRES ORAL ANTICOAGULANTS Warfarin is indicated for a number of different medical conditions that put people at risk of developing abnormal blood clots. If you are not sure why you are taking warfarin, ask your doctor or caregiver during your next appointment. ATRIAL FIBRILLATION Approximately 200,000 Canadians suffer from a condition known as atrial fibrillation or AF for short. AF is a disorder characterized by irregular, and often rapid, heartbeats and is a leading cause of stroke. AF causes the blood to stagnate in the upper chambers of the heart. There is a danger of blood clots forming and breaking free. If these clots travel to the brain, they can block the arteries that supply the brain with blood, causing a stroke. AF is most often caused by high blood pressure, although angina, previous heart attacks, overactive thyroid conditions and lung disease may also be implicated. The most common symptoms are an increased number of flutters or palpitations which may feel like "butterflies" in the chest. You may also experience chest pain, shortness of breath, dizziness and fatigue, or you might not experience any symptoms at all. Treatment often consists of medication to control the heart rhythm and anticoagulants, like warfarin, to reduce the risk of stroke. ARTIFICIAL HEART VALVES Artificial heart valves are extremely useful in correcting the mechanical problems associated with diseased heart valves. Because these artificial valves contain material that is foreign to your body, clotting can occur on the surface of the valves. Two things can happen when this kind of clotting occurs. First, the clot can remain on the artificial valve and restrict the flow of blood between the chambers of the heart and cause shortness of breath. Or the clot can become dislodged and block an artery which can cause a stroke. Anticoagulant therapy with warfarin, or warfarin plus a small amount of Aspirin ® , is very effective in preventing thrombosis of the valves and strokes. VENOUS THROMBOSIS AND PULMONARY EMBOLISM Venous thrombosis (DVT) is the term used to describe blood clots that form in the deep veins of the legs. Less commonly, clots can form in other deep veins of the body. These clots can remain in the deep veins, or break off and travel to the lung; this latter condition is called pulmonary embolism. DVT can be caused by one of the following: damage to the vein wall by injury or surgery; stimulation of blood coagulation by factors which are released into the blood stream during any severe illness; slowing of blood in the veins caused by a lack of mobility due to surgery, medical illness or injury, or travel, pregnancy, estrogen medication or other causes. Symptoms of DVT include leg pain and swelling, while pulmonary embolism may produce shortness of breath, sharp chest pain, coughing up blood or fainting. Anticoagulants, like warfarin, are often indicated, along with a type of heparin for the first 5 days of treatment, to stop the abnormal clotting process and prevent recurrence of clotting. In some patients the risk of recurrent thrombosis is markedly reduced after 3 to 6 months of treatment, while in others, the risk persists and anticoagulants are continued indefinitely. MYOCARDIAL INFARCTION Myocardial infarction is more commonly known as 'heart attack'. It is usually caused when a clot forms in a coronary artery that supplies the heart with blood and oxygen. If a clot blocks this essential supply of oxygen to the heart muscle, a heart attack can occur. Most of these clots form where arteries have become narrow due to fatty deposits on the artery walls. The most recognized symptom of myocardial infarction is chest pain which radiates down the left arm or into the jaw or neck. Most patients who suffer from a heart attack recover, but they remain at risk for further heart attacks. Recurrent blood clots can occur in the same or different coronary arteries. Clots can also form on the damaged heart muscle and become dislodged and cause a stroke. The risk of recurrent coronary artery thrombosis may last for months or years after the first episode, while the risk of stroke is usually reduced after about 3 months . Anticoagulants, like warfarin, are sometimes used to prevent recurrent blood clots and myocardial infarction. IF YOU WOULD LIKE TO RECEIVE PRACTICAL INFORMATION ABOUT WARFARIN (COUMADIN ® ) IN A LANGUAGE OTHER THAN ENGLISH OR FRENCH, ASK YOUR DOCTOR OR PHARMACIST OR CONTACT THE MEDICAL INFORMATION SERVICES OF BRISTOL-MYERS SQUIBB |