What is Coumadin® (warfarin) used for?
Coumadin® is an anticoagulant (blood thinner). Warfarin reduces the formation of blood clots.
Coumadin® may also be used for purposes not listed in this medication guide.
How should I take Coumadin® (warfarin)?
Take Coumadin® exactly as prescribed by your doctor. Follow all directions on your prescription label. Your doctor may occasionally change your dose to make sure you get the best results. Do not take Coumadin® in larger or smaller amounts or for longer than your doctor tells you to.
Take Coumadin® at the same time every day. Never take a double dose of this medicine.
You may take warfarin with or without food.
While using warfarin, you will need frequent “INR” or prothrombin time tests (to measure how long it takes your blood to clot). Your blood work will help your doctor determine the best dose for you. You must remain under the care of a doctor while taking Coumadin®.
If you have received warfarin in a hospital, call or visit your doctor 3 to 7 days after you leave the hospital. Your INR will need to be tested at that time. Do not miss any follow-up appointments.
Tell your doctor if you are sick with diarrhea, fever, chills, or flu symptoms, or if your body weight changes.
You may need to stop taking Coumadin® 5 to 7 days before having any surgery or dental work. Call your doctor for instructions. You may also need to stop taking Coumadin® if you need to take antibiotics, or if you have a spinal tap or spinal anesthesia (epidural).
How do I store Coumadin® (warfarin)?
Coumadin® is best stored at room temperature away from direct light and moisture. To prevent drug damage, you should not store Coumadin® in the bathroom or the freezer. There may be different brands of Coumadin® that may have different storage needs. It is important to always check the product package for instructions on storage, or ask your pharmacist. For safety, you should keep all medicines away from children and pets.
You should not flush Coumadin® down the toilet or pour them into a drain unless instructed to do so. It is important to properly discard this product when it is expired or no longer needed. Consult your pharmacist for more details about how to safely discard your product.
Precautions & warnings
What should I know before using Coumadin® (warfarin)?
Before using this drug, tell your doctor if:
- You are pregnant or breastfeeding. This is because, while you are expecting or feeding a baby, you should only take medicines on the recommendation of a doctor.
- You are taking any other medicines. This includes any medicines you are taking which are available to buy without a prescription, such as herbal and complementary medicines.
- You have allergy with any of active or inactive ingredients of Coumadin® or other medications.
- You have any other illnesses, disorders, or medical conditions.
You should not take Coumadin® if you have:
- Hemophilia or any bleeding disorder that is inherited or caused by disease
- A blood cell disorder (such as low red blood cells or low platelets)
- Blood in your urine or stools, or if you have been coughing up blood
- An infection of the lining of your heart (bacterial endocarditis)
- Stomach or intestinal bleeding or ulcer
- High blood pressure
- Recent or upcoming surgery on your brain, spine, or eye
- Recent head injury, aneurysm, or bleeding in the brain
- Undergo a spinal tap or spinal anesthesia (epidural)
You should not take Coumadin® if you cannot be reliable in using it because of alcoholism, psychiatric problems, dementia, or similar conditions.
Coumadin® can make you bleed more easily, especially if you have:
- A history of bleeding problems
- High blood pressure or severe heart disease
- Kidney or liver disease
- A disease affecting the blood vessels in your brain
- A history of stomach or intestinal bleeding
- A surgery or medical emergency, or if you receive any type of injection (shot)
- You are 65 or older
- You are severely ill or debilitated
Warfarin can cause birth defects, but preventing blood clots may outweigh any risks to the baby. You may be able to take Coumadin® during pregnancy if you have a mechanical heart valve. Use effective birth control to prevent pregnancy while taking this medicine and for at least 1 month after your last dose. Tell your doctor right away if you become pregnant.
It is not known whether warfarin passes into breast milk. Tell your doctor if you are breast-feeding a baby. Watch for signs of bruising or bleeding in the baby if you take Coumadin® while you are nursing.
Avoid activities that may increase your risk of bleeding or injury. Use extra care to prevent bleeding while shaving or brushing your teeth. You may still bleed more easily for several days after you stop taking Coumadin.
Avoid drinking alcohol.
Grapefruit juice, cranberry juice, noni juice, and pomegranate juice may interact with warfarin and lead to unwanted side effects. Avoid the use of these juice products while taking Coumadin®.
Avoid making any changes in your diet without first talking to your doctor. Foods that are high in vitamin K (liver, leafy green vegetables, or vegetable oils) can make warfarin less effective. If these foods are part of your diet, eat a consistent amount on a weekly basis.
Ask your doctor before taking any medicine for pain, arthritis, fever, or swelling. This includes acetaminophen (Tylenol), aspirin, ibuprofen (Advil, Motrin), naproxen (Aleve), celecoxib (Celebrex), diclofenac, indomethacin, meloxicam, and others. These medicines may affect blood clotting and may also increase your risk of stomach bleeding.
Is it safe during pregnancy or breastfeeding?
There isn’t enough information about the safety of using this medication during pregnancy and breastfeeding. Please always consult with your doctor to weigh the potential benefits and risks before taking this medication.
What side effects can occur from Coumadin® (warfarin)?
Common side effects may include:
- Mild stomach pain
- Bloating, gas
- Altered sense of taste
Also call your doctor at once if you have:
- Pain, swelling, hot or cold feeling, skin changes, or discoloration anywhere on your body
- Sudden and severe leg or foot pain, foot ulcer, purple toes or fingers
- Sudden headache, dizziness, or weakness
- Easy bruising or bleeding (nosebleeds, bleeding gums), purple or red pinpoint spots under your skin
- Bleeding from wounds or needle injections that will not stop
- Pale skin, feeling light-headed or short of breath, rapid heart rate, trouble concentrating
- Dark urine, jaundice (yellowing of the skin or eyes)
- Little or no urinating
- Numbness or muscle weakness
- Pain in your stomach, back, or sides
Get emergency medical help if you have signs of an allergic reaction to Coumadin®: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Coumadin® may cause you to bleed more easily, which can be severe or life-threatening. Seek emergency medical attention if you have any unusual bleeding, or bleeding that will not stop. You may also have bleeding on the inside of your body, such as in your stomach or intestines. Call your doctor at once if you have blood in your urine, black or bloody stools, or if you cough up blood or vomit that looks like coffee grounds.
Not everyone experiences these side effects. There may be some side effects not listed above. If you have any concerns about a side-effect, please consult your doctor or pharmacist.
What drugs may interact with Coumadin® (warfarin)?
Coumadin® may interact with other drugs that you are currently taking, which can change how your drug works or increase your risk for serious side effects. To avoid any potential drug interactions, you should keep a list of all the drugs you are using (including prescription drugs, nonprescription drugs, and herbal products) and share it with your doctor and pharmacist. For your safety, do not start, stop, or change the dosage of any drugs without your doctor’s approval.
Products that may interact with this drug are:
- Other medicines to prevent blood clots
- Medicine to treat any type of infection, including tuberculosis
- Supplements that contain vitamin K
- An antidepressant – citalopram, duloxetine, fluoxetine, fluvoxamine, paroxetine, sertraline, venlafaxine, vilazodone, and others
- Seizure medicine – carbamazepine, phenobarbital, phenytoin
- Herbal (botanical) products – coenzyme Q10, cranberry, echinacea, garlic, ginkgo biloba, ginseng, goldenseal, or St. John’s wort
Does food or alcohol interact with Coumadin® (warfarin)?
Coumadin® may interact with food or alcohol by altering the way the drug works or increase the risk for serious side effects. Please discuss with your doctor or pharmacist any potential food or alcohol interactions before using this drug.
What health conditions may interact with Coumadin® (warfarin)?
Coumadin® may interact with your health condition. This interaction may worsen your health condition or alter the way the drug works. It is important to always let your doctor and pharmacist know all the health conditions you currently have.
Health conditions that may interact with this drug are:
- Celiac sprue (an intestinal disorder)
- Congestive heart failure
- Overactive thyroid
- A connective tissue disorder such as Marfan Syndrome, Sjögren syndrome, scleroderma, rheumatoid arthritis, or lupus
- A hereditary clotting deficiency (warfarin may make your symptoms worse at first)
- If you use a catheter
- If you have ever had low blood platelets after receiving heparin
The information provided is not a substitute for any medical advice. You should ALWAYS consult with your doctor or pharmacist before using Coumadin® (warfarin).
What is the dose of Coumadin® (warfarin) for an adult?
Venous Thromboembolism (including deep venous thrombosis [DVT] and PE)
Adjust the warfarin dose to maintain a target INR of 2.5 (INR range, 2.0-3.0) for all treatment durations. The duration of treatment is based on the indication as follows:
- For patients with a DVT or PE secondary to a transient (reversible) risk factor, treatment with warfarin for 3 months is recommended.
- For patients with an unprovoked DVT or PE, treatment with warfarin is recommended for at least 3 months. After 3 months of therapy, evaluate the risk-benefit ratio of long-term treatment for the individual patient.
- For patients with two episodes of unprovoked DVT or PE, long-term treatment with warfarin is recommended.
- For a patient receiving long-term anticoagulant treatment, periodically reassess the risk-benefit ratio of continuing such treatment in the individual patient.
In patients with non-valvular AF, anticoagulate with warfarin to target INR of 2.5 (range, 2.0-3.0).
- In patients with non-valvular AF that is persistent or paroxysmal and at high risk of stroke (i.e., having any of the following features: prior ischemic stroke, transient ischemic attack, or systemic embolism, or 2 of the following risk factors: age greater than 75 years, moderately or severely impaired left ventricular systolic function and/or heart failure, history of hypertension, or diabetes mellitus), long-term anticoagulation with warfarin is recommended.
- In patients with non-valvular AF that is persistent or paroxysmal and at an intermediate risk of ischemic stroke (i.e., having 1 of the following risk factors: age greater than 75 years, moderately or severely impaired left ventricular systolic function and/or heart failure, history of hypertension, or diabetes mellitus), long-term anticoagulation with warfarin is recommended.
- For patients with AF and mitral stenosis, long-term anticoagulation with warfarin is recommended.
- For patients with AF and prosthetic heart valves, long-term anticoagulation with warfarin is recommended; the target INR may be increased and aspirin added depending on valve type and position, and on patient factors.
Mechanical and Bioprosthetic Heart Valves
- For patients with a bileaflet mechanical valve or a Medtronic Hall (Minneapolis, MN) tilting disk valve in the aortic position who are in sinus rhythm and without left atrial enlargement, therapy with warfarin to a target INR of 2.5 (range, 2.0-3.0) is recommended.
- For patients with tilting disk valves and bileaflet mechanical valves in the mitral position, therapy with warfarin to a target INR of 3.0 (range, 2.5-3.5) is recommended.
- For patients with caged ball or caged disk valves, therapy with warfarin to a target INR of 3.0 (range, 2.5-3.5) is recommended.
- For patients with a bioprosthetic valve in the mitral position, therapy with warfarin to a target INR of 2.5 (range, 2.0-3.0) for the first 3 months after valve insertion is recommended. If additional risk factors for thromboembolism are present (AF, previous thromboembolism, left ventricular dysfunction), a target INR of 2.5 (range, 2.0-3.0) is recommended.
- For high-risk patients with MI (e.g., those with a large anterior MI, those with significant heart failure, those with intracardiac thrombus visible on transthoracic echocardiography, those with AF, and those with a history of a thromboembolic event), therapy with combined moderate-intensity (INR, 2.0-3.0) warfarin plus low-dose aspirin (≤100 mg/day) for at least 3 months after the MI is recommended.
What is the dose of Coumadin® (warfarin) for a child?
The dosage has not been established in pediatric patients. It may be unsafe for your child. It is always important to fully understand the safety of the drug before using. Please consult with your doctor or pharmacist for more information.
How is Coumadin® (warfarin) available?
Coumadin® is available in the following dosage forms and strengths:
- Tablet: warfarin sodium 1mg
- Injection, powder, lyophilized, for solution warfarin sodium 2mg in 1mL
What should I do in case of an emergency or overdose?
In case of an emergency or an overdose, call your local emergency services or go to your nearest emergency room.
What should I do if I miss a dose?
If you miss a dose of Coumadin®, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and take your regular dose as scheduled. Do not take a double dose.
Hello Health Group does not provide medical advice, diagnosis or treatment.
Coumadin®. https://www.drugs.com/coumadin.html. Accessed July 19, 2017
Coumadin®. http://www.webmd.com/drugs/2/drug-4069/coumadin-oral/details. Accessed July 19, 2017
Review Date: July 19, 2017 | Last Modified: July 19, 2017