Coumadin

The active ingredient in Coumadin is warfarin, which is a blood thinner.

It works by interfering with the body's natural blood clotting process. It inhibits the action of vitamin K, an essential nutrient required for the production of clotting factors II, VII, IX, and X in the liver as well as proteins S and C. By reducing the levels of these clotting factors, Coumadin helps to prevent the formation of blood clots.

Follow all directions given by your doctor and read all documents provided, including the full prescribing information, FDA-approved product labeling, Instructions for Use, and Medication Guide before using Coumadin. However, the following is a synopsis of the general guidelines for the use of Coumadin:

• You can take Coumadin with or without food. If it is hurting your stomach, try taking the medication with food.
• Be consistent with the time you take Coumadin.
• It is important that you are consistent with how much vitamin K-rich foods you eat, such as spinach and Brussels sprouts. This is because vitamin K changes how well Coumadin works. Talk to your healthcare provider if you are having significant changes in your diet as this might affect your INR results as well as other blood tests.
• You most likely, and are highly recommended, to take a blood test regularly known as an international normalized ratio (INR) test or prothrombin time (PT) test. It is recommended that you put the time of your appointments in your calendar to ensure you make your appointments on time and do not miss them.
• If you miss a dose of Coumadin, take the missed dose as soon as you remember. However, if it is closer to the time of your next dose, skip this dose and take your next dose as soon as you remember. Do not double your dose or take extra doses to make up for a missed dose.

The most common side effects of Coumadin seen in clinical trials as compared to placebo include:

• Bruising
• Bleeding
• Nausea
• Rash
• Diarrhea
• Vomiting
• Itching
• Chills
• Change in taste

Some individuals may experience serious side effects while using Coumadin. These side effects may require immediate medical attention. If you experience any of the following, contact your healthcare provider or seek emergency medical help:

• Serious bleeding
• Signs of bleeding problems that you should look out for are: swelling, feeling very weak or dizzy, pain, unusual bruising, nosebleeds, bleeding gums, heavy menstrual periods or abnormal vaginal bleeding, bloody or tarry stools, blood in your urine, coughing up blood (especially blood that looks like coffee grounds), and unusual bleeding.
• Calciphylaxis (calcium build-up in your blood vessels)
• Gangrene and skin or tissue death (necrosis)
• Coumadin should be discontinued if necrosis occurs. Alternative drugs can be explored if continued anticoagulation therapy is necessary.

These are not all of the possible side effects of Coumadin. You should always seek medical advice from your healthcare provider for any questions or concerns about your medical condition or treatment. Read all patient information, medication guides, or drug information sheets that come with this medication. You can also report adverse effects to the Food and Drug Administration at www.fda.gov/medwatch or 1-800-FDA-1088.

Before starting Coumadin, it is crucial to discuss any existing health conditions with your healthcare provider. You should be sure that your healthcare provider is aware of all your medical conditions, including if you have:

• Recently had or are scheduled to have surgery on your spine, brain, or eye
• Any upcoming dental procedures
• High blood pressure or serious heart disease
• Kidney disease or a history of kidney disease
• Liver disease or a history of liver disease
• Undergone a spinal anesthesia or spinal tap (epidural)
• Heparin-induced thrombocytopenia
• Warfarin should not be given until your platelet count has normalized or improved.

Boxed warnings

Coumadin does carry a box warning. First, it can cause major or fatal bleeding.

Medical professionals should carry out regular INR monitoring if you are taking Coumadin.

Dietary changes, drugs, and other factors can affect your INR levels which are achieved with Coumadin therapy.

Your healthcare provider can give you instructions on how to minimize your risk of bleeding, and to report symptoms and signs of bleeding to your healthcare professional.

You should not take Coumadin in the following situations:

• Pregnancy, except in women with mechanical heart valve
• Active bleeding
• Recent or planned surgery
• Spinal puncture, or other procedures with potential to cause uncontrolled bleeding
• Severely high blood pressure

Warfarin starts affecting the clotting process within 24 to 72 hours, but the full anticoagulant effect may not be seen for 5 to 7 days.

When Coumadin is taken with other prescription drugs, over-the-counter medications, vitamins, and supplements, it may change how they work or increase the frequency or severity of side effects. Make sure that you tell your healthcare professional about anything that you are taking, including:

• Inducer and inhibitors of CYP2C9, 1A2, or 3A4
• These may alter warfarin exposure. You should monitor INR closely when any such drug is used with Coumadin.
• Drugs that have the potential to increase bleeding risk
• This includes other anticoagulants, nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen and naproxen, antiplatelet agents, and selective serotonin reuptake inhibitors (SSRIs).
• Certain antibiotics and antifungals
• INR should be closely monitored when starting or stopping an antifungal or antibiotic course of therapy.
• Botanical (herbal) products
• Some of these products may influence your response to Coumadin. This includes St. John’s wort.
• INR should be closely monitored.
• Grapefruit juice, cranberry juice, noni juice, and pomegranate juice
• These have the potential to interact with warfarin and lead to unwanted side effects

Coumadin comes as scored tablets in the following dose of warfarin strengths:

1 mg

2 mg

2.5 mg

3 mg

4 mg

5 mg

6 mg

7.5 mg

10 mg

Coumadin should be stored away from excessive light and moisture. Keep the medication at room temperature unless otherwise instructed by your healthcare professional.

Coumadin (warfarin) is manufactured by Bristol Myers Squibb, a global biopharmaceutical company.

Low-cost generics are available for Coumadin. The generic is known as warfarin, and the brand names include Coumadin and Jantoven.

To stop using Coumadin, it's important to consult with your healthcare provider for a safe discontinuation plan. Stopping abruptly may increase your risk of blood clots.

Coumadin can cause birth defects and severe harm to you and your unborn baby. It should be only used in pregnancy if the benefit is clearly greater than the risk, such as if you are at high risk for clots.

Talk to your doctor if you are already pregnant or if you have any plans to become pregnant.

Talk to your doctor if you are already breastfeeding or if you have any plans to breastfeed. They will know or recommend what is best for you. It is currently recommended that breastfeeding women should be monitored, as well as their breastfeeding infants for bleeding. That means that breastfeeding infants should undergo INR monitoring.