Warfarin: What is it, what is it used for, how and when is it taken?

belonging to the family of anticoagulants. More precisely, it is a vitamin K antagonist which must be administered orally to carry out its therapeutic action.

Shutterstock Warfarin - Chemical Structure

In fact, warfarin is found in medicines formulated in tablet form. The active ingredient is probably better known by the trade name of the only medicine that currently (September 2020), in our country, contains it: Coumadin®. To be purchased, this medicine would require the presentation of a repeatable medical prescription (RR ); however, being classified as a group A drug, its cost can be reimbursed by the National Health System (SSN).

in the blood which can cause a blockage of blood flow with all the consequences of the case.

More specifically, warfarin is used for the treatment and prevention of clots:

• Associated with atrial fibrillation;
• Associated with heart valve replacement;
• In the lungs;
• In the legs.

In patients who have suffered a heart attack, however, warfarin is indicated to reduce the risk of a new heart attack, stroke and to decrease the risk of blood clots reaching the legs and lungs.

of bleeding or if you notice any type of unusual bleeding going on;

You have suffered from stomach and / or intestinal bleeding in the past;

We have or have had in the past an INR greater than 4 or very variable;

You have hypertension or have high blood pressure;

You have anemia or someone in your family suffers from blood disorders;

You have a reduced number of platelets following treatment with heparin (another anticoagulant);

There is an "inflammation of the blood vessels;

There are pathologies involving the blood vessels of the head;

You have a malignant tumor;

You suffer from kidney and / or liver disorders or diseases;

You have a catheter;

You must undergo surgery of any kind, including eye and dental surgery;

You have a disease involving protein C;

You have diabetes;

You have no appetite and eat little;

You have high levels of blood cells;

Low blood levels of albumin occur;

Hyperphosphatemia or hypercalcemia occurs;

You suffer from vitamin K deficiency;

You are taking any medications or foods that contain vitamin K.

During warfarin therapy, however, the doctor should be immediately advised if:

• The toes turn blue and are sore;
• Vomiting, diarrhea, or infections occur;
• Necrosis of the skin and tissues appears;
• Painful and itchy spots or nodules appear on the skin which can then worsen and cause swelling, paleness and take on a blackish color up to ulceration and infection of the affected area (calciphylaxis);
• You make a bad fall or hit your head;
• You have to undergo surgery of any kind.

(used to dissolve blood clots);

Antibiotic drugs of any type (for example, penicillins, cephalosporins, macrolides, sulfonamides, rifamycins, etc.);

Antifungal drugs;

Antiviral drugs;

Antiparasitic drugs;

Immunosuppressive drugs (for example, cyclosporine, etc.);

Non-steroidal anti-inflammatory drugs (NSAIDs) of any type and corticosteroid drugs;

Antidepressant drugs of any type;

Medicines for the treatment of:

• Insomnia;
• Epilepsy;
• Parkinson's disease;
• Anxiety and other psychiatric conditions;
• Diseases of the thyroid gland;
• Urinary incontinence;
• Symptoms of menopause;
• BPH;
• Cardiac disorders and rhythm disturbances;
• Rheumatoid arthritis;
• Lack of production of coenzyme Q10 (such as ubiquinone or ubidecarenone);
• Digestive disorders;
• Gout;
• Intestinal inflammations.

Psychostimulants such as methylphenidate;

Antitussive drugs;

Leukotriene antagonists such as zafirlukast;

Anticancer drugs;

Contraceptive drugs;

Drugs that increase metabolism;

Antidiabetic drugs;

Medicines to treat low blood sugar levels

Antihypertensive drugs;

Statins, fibrate drugs, and other cholesterol-lowering drugs;

Proton pump inhibitors and H2 receptor antagonists;

Antiemetic drugs;

Danazol;

Orlistat;

Vaccines;

Medicines or products (including herbal) for the treatment of dementia;

Alcohol-containing drugs;

Ointments containing methylsalicylate or trolamine salicylate;

Hypericum or St. John's wort drugs and products;

Medicines and supplements of vitamins E, C and K.

However, before starting warfarin therapy, you should tell your doctor if you are taking, have recently taken or intend to take any medications or products of any kind - even if not expressly listed above - including non-prescription medicines (SOP), over-the-counter (OTC) medicines, herbal and phytotherapeutic products, etc.