Warfarin – what it is, what it is for, how to take it and contraindications!

Sodium warfarin (active substance) is an anticoagulant that acts to inhibit vitamin K -dependent clotting factors .

The aim of anticoagulant therapy is to reduce the blood ‘s ability to clot so as to prevent thrombosis and at the same time prevent spontaneous bleeding from occurring.

Warfarin is rapidly and completely absorbed after oral administration. Its onset of anticoagulant action, however, only occurs 24 to 72 hours after oral administration, and its maximum anticoagulant effect can occur in 72 to 96 hours. The duration of action of a single dose of Warfarin Sodium (active substance) is 2 to 5 days.

Warfarin is an anticoagulant ( blood thinner). Warfarin reduces the formation of blood clots. Warfarin is used to treat or prevent blood clots in veins or arteries, which can reduce the risk of stroke, heart attack, or other serious conditions . Warfarin may also be used for purposes not listed in this medication guide.

Important information about warfarin:

You should not take warfarin if you are prone to bleeding because of a medical condition, if you have upcoming surgery, or if you need a lumbar or epidural puncture. Do not take warfarin if you cannot take it on time each day.

Warfarin increases your risk of serious or fatal bleeding, especially if you have certain medical conditions, if you are 65 years of age or older, if you have had a stroke, or if you have bleeding from your stomach or intestines. Seek emergency help if you have any bleeding that won’t stop.

Contact your doctor right away if you have other signs of bleeding, such as: swelling , pain, feeling weak or dizzy, bruising, nosebleeds, nosebleeds, heavy menstruation or abnormal vaginal bleeding, blood in your urine, bloody stools or stools of tar. , coughing up blood or vomit that looks like coffee beans .

Many other medications can increase the risk of bleeding when used with warfarin. Tell your doctor about any medications you’ve used recently. Avoid making any changes to your diet without first talking to your doctor. Some foods can make warfarin less effective.

Precautions before taking:

You should not take warfarin if you are allergic to it, or if:

• You have very high blood pressure;
• Have you recently had or will have surgery on your brain, spine or eye;
• You have a lumbar puncture or spinal (epidural) anesthesia;
• You cannot take warfarin on time every day.

You should also not take this medication if you are prone to bleeding because of a medical condition, such as:

• A blood cell disorder (such as low red blood cells or low platelets);
• Ulcers or bleeding in the stomach, intestines, lungs or urinary tract;
• An aneurysm or bleeding in the brain;
• An infection of the lining of your heart.

Do not take warfarin if you are pregnant unless your doctor tells you to. Warfarin can cause birth defects, but preventing blood clots can outweigh any risks to the baby. If you are not pregnant, use effective birth control to prevent pregnancy while you are taking warfarin and for at least 1 month after your last dose. Tell your doctor right away if you become pregnant.

Warfarin can make you bleed more easily, especially if you’ve had:

• High blood pressure or severe heart disease;
• Kidney disease;
• Cancer or low blood cell counts;
• An accident or surgery;
• Bleeding in your stomach or intestines;
• Leak;
• If you are 65 years old or older.

To make sure warfarin is safe for you, tell your doctor if you’ve ever had:

• Diabetes;
• Congestive heart failure;
• Liver disease, kidney disease (or if you are on dialysis);
• An inherited clotting deficiency;
• Low blood platelets after receiving heparin.

It is not known whether warfarin passes into breast milk. Pay attention to signs of bruising or bleeding in the baby if you take this medication while you are breastfeeding a baby.

How should I take warfarin?

Take Warfarin exactly as prescribed by your doctor. Follow all instructions on your prescription label. Your doctor may occasionally change your dose. Do not take warfarin in larger or smaller amounts or for longer than your doctor tells you.

Take Warfarin at the same time each day, with or without food. Never take a double dose. Warfarin can make it easier for you to bleed. Seek emergency help if you have any bleeding that won’t stop.

You will need frequent INR or prothrombin time tests (to measure blood clotting time and determine your warfarin dose). You must remain under the care of a physician while taking this medication.

If you are given Warfarin in a hospital, call or visit your doctor 3 to 7 days after leaving the hospital. Your INR will need to be tested at this point. Don’t miss any follow-up appointments.

Tell your doctor if you have diarrhea, fever, chills or flu-like symptoms, or if your body weight changes. You may need to stop taking warfarin for 5 to 7 days before having any surgery, dental treatment, or medical procedure. Call your doctor for instructions.

Wear a medical alert tag or carry an ID card saying you take Warfarin. Any healthcare provider who treats you should know that you are taking this medicine. Store at room temperature away from heat, moisture and light.

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up for the missed dose.

What should I avoid while taking it?

Avoid activities that could increase your risk of bleeding or injury. Take special care to avoid bleeding when shaving or brushing your teeth. You may still bleed more easily for several days after you stop taking warfarin.

Avoid making any changes to your diet without first talking to your doctor. Foods rich in vitamin K (liver, green leafy vegetables, or vegetable oils) can make warfarin less effective. If these foods are part of your diet , consume a consistent amount weekly.

Grapefruit juice, cranberry juice, noni juice, and pomegranate juice can all interact with warfarin and lead to unwanted side effects. Avoid using these juice products while taking this medication. Avoid drinking alcohol.

Ask your doctor before using any medication for pain, arthritis , fever, or swelling . This includes aspirin, ibuprofen (Advil, Motrin), naproxen (Aleve), celecoxib (Celebrex), diclofenac, indomethacin, meloxicam, and others. These medications can affect blood clotting and can also increase the risk of stomach bleeding.

Warfarin side effects:

Get emergency medical help if you have signs of an allergic reaction to warfarin: hives; breathing difficulty; swelling of the face, lips, tongue or throat. Warfarin increases the risk of bleeding, which can be severe or life-threatening. Call your doctor right away if you have any signs of bleeding, such as:

• Sudden headache, feeling very weak or dizzy
• Swelling , pain, unusual bruising;
• Bleeding gums, nosebleeds;
• Bleeding from wounds or needle injections that won’t stop
• Heavy menstrual periods or abnormal vaginal bleeding;
• Blood in your urine, blood or dark stools
• Coughing up blood or vomit that resembles coffee grounds .

Clots formed by warfarin can block normal blood flow, which could lead to tissue death or amputation of the affected body part. Get medical help right away if you have:

• Pain, swelling , feeling hot or cold, skin changes or discoloration anywhere on the body
• Sudden, severe pain in the leg or foot, foot ulcer, purple toes or toes.
• Bleeding is the most common side effect of warfarin.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects.

Warfarin dosage information

The duration of treatment is undetermined and the usual adult dose of warfarin for the prevention of thromboembolism in atrial fibrillation is:

• Starting dose: 2 to 5 mg orally once daily
• Maintenance dose: 2 to 10 mg orally once daily
• Target INR: 2.5 (range 2 to 3)

Comments:

• For patients with atrial fibrillation (AF) and prosthetic heart valves, the target INR can be increased depending on valve type, valve position, and patient factors.
• The starting dose is influenced by age, race, body weight, gender, concomitant medications, comorbidities, genetic variation and possibly other factors.
• Dosage and administration should be individualized according to the patient’s INR and the condition being treated.

Use: Prophylaxis and treatment of thromboembolic complications associated with AF.

The duration of treatment is undetermined and the Usual Adult dose of Warfarin for Thromboembolic Stroke Prophylaxis is:

• Starting dose: 2 to 5 mg orally once daily
• Maintenance dose: 2 to 10 mg orally once daily
• Target INR: 2.5 (range 2 to 3)

Comments:

• For patients with atrial fibrillation (AF) and prosthetic heart valves, the target INR can be increased depending on valve type, valve position, and patient factors.
• The starting dose is influenced by age, race, body weight, gender, concomitant medications, comorbidities, genetic variation and possibly other factors.
• Dosage and administration should be individualized according to the patient’s INR and the condition being treated.

Use: Prophylaxis and treatment of thromboembolic complications associated with AF.

Usual adult dose of warfarin for myocardial infarction:

• Starting dose: 2 to 5 mg orally once daily
• Maintenance dose: 2 to 10 mg orally once daily
• INR: 2 a 3

Duration of treatment: At least 3 months after myocardial infarction

Comments:

• Starting dose is influenced by age, race, body weight, sex , concomitant medications, comorbidities, genetic variation and possibly other factors.
• Dosage and administration should be individualized according to the patient’s INR and the condition being treated.

Use: Reduced risk of death, recurrent myocardial infarction (MI) and thromboembolic events such as stroke or systemic embolization after myocardial infarction.

Usual adult dose of warfarin for myocardial infarction – prophylaxis:

• Starting dose: 2 to 5 mg orally once daily
• Maintenance dose: 2 to 10 mg orally once daily
• INR: 2 a 3

Duration of treatment: At least 3 months after myocardial infarction

Comments:

• Starting dose is influenced by age, race, body weight, sex , concomitant medications, comorbidities, genetic variation and possibly other factors.
• Dosage and administration should be individualized according to the patient’s INR and the condition being treated.

Use: Reduced risk of death, recurrent myocardial infarction (MI) and thromboembolic events such as stroke or systemic embolization after myocardial infarction.

What other drugs will affect warfarin?

Many medications (including some over-the-counter drugs and herbal products) can affect your INR and increase your risk of bleeding if you take them with warfarin. Not all possible drug interactions are listed in this medication guide. It is very important to ask your doctor and pharmacist before starting or stopping any other medication, especially:

• Other medicines to prevent blood clots;
• An antibiotic or antifungal medication;
• Supplements containing vitamin K ; or
• Herbal (botanical) products – coenzyme Q10, cranberry, echinacea, garlic, ginkgo biloba, ginseng, goldenseal or St. John’s wort.

This list is not complete and many other drugs can interact with warfarin. This includes prescription and over-the-counter drugs, vitamins and herbal products. Give a list of all your medications to any healthcare provider who treats you.

Other information:

Remember, keep this and all other medications out of the reach of children, never share your medications with others, and use warfarin only for the indication prescribed. Always consult your physician to ensure that the information displayed on this page applies to your personal circumstances.