Indications 

Coumadin is an anticoagulant medication indicated to treat and prevent blood clots from forming in the body. It is usually prescribed to treat the following: 

• Prophylaxis and management of venous thrombosis and its potential complication, pulmonary embolism 
• Prevention and treatment of thromboembolic complications in patients with atrial fibrillation and those who have undergone cardiac valve replacement 
• Mitigation of the risk of mortality, recurrent myocardial infarction, and thromboembolic events such as stroke or systemic embolization following myocardial infarction 

Warfarin, the active ingredient of Coumadin, works by blocking an important enzyme called vitamin K epoxide reductase complex 1 (VKORC1), which is needed to activate vitamin K in our body.  

This action reduces the amount of active clotting factors produced by our body. Vitamin K is needed to make certain clotting factors that help our blood clot normally. Without enough vitamin K, our body cannot produce these clotting factors, which can help prevent blood clots from forming. 

Uses and Dosage 

Before starting treatment with Coumadin, and with each subsequent refill, carefully read its patient information leaflet and medication guide. For any questions or clarification, consult with a qualified healthcare professional. 

The dosing and administration of Coumadin require personalized consideration for each patient, considering various factors such as the patient’s INR response to the medication, age, race, body weight, sex, other concurrent medications, and comorbid conditions. 

Your doctor or healthcare provider will keep a close eye on you while taking this medication to determine the appropriate dose for you. 

Typically, Coumadin is administered once a day without regard to food intake.  

Adhere to your doctor’s prescribed dosage regimen and instructions, and refrain from altering the dosage, frequency, or discontinuing the medication without consulting them. 

Consistent and regular use of Coumadin is recommended to maximize its therapeutic effects. Try to take it at the same time each day to assist with remembering and maintaining a regular dosing schedule. 

Side Effects 

Potential adverse reactions associated with the use of Coumadin are listed below. If any of them persist or worsen, inform your doctor. 

Common Side Effects 

• Easy bruising and bleeding 
• Nausea 
• Vomiting 
• Stomach pain 
• Bloating 
• Flatulence 
• Altered sense of taste 

Serious Side Effects  

• Increased risk of bleeding, which can be severe or life-threatening. Promptly contact your physician if you experience any indications of bleeding, such as: 
• Sudden onset of headache accompanied by feelings of weakness or dizziness 
• Unusual swelling, pain, or bruising 
• Bleeding from gums or nose 
• Uncontrolled bleeding from wounds or injection sites 
• Heavy menstrual periods or abnormal vaginal bleeding 
• Presence of blood in the urine or the appearance of bloody or dark stools 
• Coughing up blood or vomiting material that resembles coffee grounds 
• Formation of small blood clots (usually at the beginning of treatment). These clots may block normal blood flow, which can potentially cause tissue death or necessitate amputation of the affected body part. Seek medical attention immediately if you experience the following symptoms: 
• Pain, swelling, hot or cold feeling, skin changes, or discoloration anywhere on your body 
• Sudden and severe leg or foot pain/ulcer, purple toes, or fingers. 
• Hypersensitivity or allergic reactions involving the immune system, including urticaria and anaphylaxis 
• Vasculitis affecting the blood vessels 
• Hepatitis or elevated liver enzymes in the hepatobiliary system; cholestatic hepatitis may result from concomitant administration of Coumadin and ticlopidine 
• Skin disorders, including rash, dermatitis, bullous eruptions, pruritus, and alopecia 
• Respiratory disorders, such as tracheal or tracheobronchial calcification 
• General disorders, such as chills 

Get medical help immediately if any of the above serious side effects are experienced. 

Allergic Reactions 

Severe allergic responses to Coumadin are rare. However, if you notice the symptoms listed below, get emergency medical help immediately.  

• Hives 
• Difficult breathing 
• Swelling of the face, lips, tongue, or throat 

The side effects of Coumadin listed here are incomplete. In case of unlisted bothersome side effects, consult a healthcare professional. 

Cautions 

Before using Coumadin, inform your doctor or pharmacist of all known allergies. This medication’s inactive ingredients may trigger allergic reactions or other adverse effects. Consult your pharmacist for additional information. 

Disclose your medical history to your doctor, particularly if you have had any of the following conditions: 

• Any blood disorders (e.g., anemia, hemophilia) 
• Bleeding problems (e.g., gastrointestinal, or intracranial bleeding) 
• Blood vessel disorders (e.g., aneurysms) 
• Recent significant injury or surgery 
• Kidney or liver disease 
• Mental or mood disorders (including memory impairment) 
• Frequent falls/injuries 

To avoid potential drug interactions, tell your doctor or pharmacist of all medications you are currently taking, including prescription/non-prescription, supplements, and herbal products, especially: 

• Other medicines to prevent blood clots 
• Antibiotics or antifungal medications 
• Vitamin K supplements 
• Various herbal products such as coenzyme Q10, cranberry, echinacea, garlic, ginkgo biloba, ginseng, goldenseal, and St. John’s wort 

This is not an exhaustive list of drugs that can potentially interact with warfarin. Consult your doctor for more information.  

Coumadin can increase the risk of heavy bleeding. Take extra caution while handling sharp objects to reduce the chances of getting injured or bruised. 

When brushing your teeth, use a soft toothbrush. Avoid participating in contact sports or activities that can cause injury. 

If you fall or injure yourself, particularly if you hit your head, contact your doctor immediately.  

Before surgery or any medical/dental procedures, tell your doctor or dentist you are taking Coumadin. 

Maintain a consistent and balanced diet while taking Coumadin. Certain foods can impact how the medication functions in your body, potentially altering your dosage and treatment.  

Avoid sudden and significant changes in consuming foods high in vitamin K, such as kale, spinach, broccoli, liver, and green tea. Consult with your doctor before attempting to go on a diet if you are trying to lose weight. 

Coumadin should not be used in pregnant women unless they have mechanical heart valves, are at high risk of thromboembolism, and when the potential benefits of using this medication outweigh the potential risks. 

Due to the potential harm this medication can cause an unborn baby, pregnant women should not handle this medication or inhale the dust from the tablets, as the drug can be absorbed through the skin and lungs. 

Small amounts of warfarin may pass into breast milk, but it is unlikely to cause harm to a nursing infant. Consult with your doctor before breastfeeding while taking this medication.