Warfarin

Warfarin is a medicinal product whose main function is not to allow blood to clot.

Its action is to suppress vitamin K, which is actively involved in the process of blood clotting. The main task of such an effect on the body is to prevent the formation of blood clots. This drug is used for thrombosis in the veins.

On this page you will find all information about Warfarin: the full instructions for use on this medication, average prices in pharmacies, complete and incomplete analogs of the drug, as well as reviews of people who have already used Warfarin. Want to leave your opinion? Please write in the comments.

Clinical and pharmacological group

Anticoagulant of indirect action.

Conditions of leave from pharmacies

It is released on prescription.

Price list

How much does Warfarin cost? The average price in pharmacies is at the level of90 rubles.

Form of issue and composition

Produced in the form of tablets. Warfarin - a tablet of round shape, light blue, with a cruciform risk. Tablets are packed in plastic bottles of 50 or 100 pieces each. The vials are closed with lids, which are screwed on.

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The composition of 1 tablet includes the active substance - sodium warfarin in an amount of 2.5 mg.
Additional ingredients: corn starch, lactose, indigocarmine calcium dihydrate hydrophosphate, magnesium stearate, povidone 30.

Pharmacological effect

Anticoagulant effect of Warfarin (Warfarina Nycomed) is carried out by inhibiting or slowing the synthesis dependent on vitamin K coagulation factors in the liver (disrupts the biosynthesis of proteins of its coagulation).

Since the drug does not affect the coagulation of blood clots directly in the bloodstream, the effect of taking begins approximately on the third or fifth days. Warfarin (Warfarin Nycomed) has a long half-life, high bioavailability (more than 90 percent).

Indications for use

Described drug is recommended for prevention and treatment of the following diseases:

Varicose veins.
Hemorrhoids.
Thrombophlebitis.
Recurrent venous thrombosis.
Postoperative thrombosis.
Thrombosis of proximal and deep veins.
Thrombosis of cerebral vessels.
Thromboembolism of the pulmonary artery, including repeated.
Repeated myocardial infarction.
Damage to the heart valves.
Atrial fibrillation.
Thromboembolic complications in the implantation of artificial valves or the transplantation of blood vessels.

Conduction of surgical or thrombolytic treatment of thrombosis also requires the use of Warfarin. This medication is also used during the recovery period after any surgery, during which the patient received too many drugs to stop the blood.

Contraindications

Usually, doctors do not prescribe this remedy to patients with:

hemorrhagic stroke;
bacterial endocarditis;
aneurysms;
recently suffered craniocerebral or ophthalmological operations;
acute bleeding or the likelihood of their discovery;
thrombocytopenia;
pericarditis (especially exudative);
severe form of arterial hypertension;
infirmities of kidneys and liver.

Also, a contraindication to taking a substance is an increased sensitivity to it or a tendency to alcoholism and psychosis.

Application in pregnancy and lactation

Warfarin easily penetrates the placental barrier, can provoke fetal hemorrhagic disorders, anomalies of bone development tissue, atrophy of the optic nerve and cataract, up to blindness, retardation of physical and mental development, microcephaly. Therefore, the drug is contraindicated in pregnant women.

With breast milk, warfarin is secreted in an inactive form. When taking the drug as a lactating woman in children, there were no changes in the pattern of coagulation. Accordingly, warfarin can be used during lactation. The effect of Warfarin on the body of preterm neonates has not been studied.

Instructions for use

The instructions for use indicate that Warfarin is taken orally, 1 time / day, at the same time.

The initial dose is 2.5-5 mg / day. The further dosage regimen is set individually, depending on the results of the prothrombin time or MNO. Prothrombin time should be increased 2-4 times from the initial, and INR should reach 2.2-4.4 depending on from the disease, the risk of thrombosis, the risk of bleeding and individual characteristics of the patient.

When determining INR, the thromboplastin sensitivity index should be taken into account and use this index as the correction factor (1.22 - when using domestic thromboplastin from the brain of a rabbit "Neoplast" and 1.2 - using a thromboplastin firm "Rosh Diagnostics").

In the case of atrial fibrillation and with maintenance therapy for thrombosis, veins and thromboembolism achieve a moderate anticoagulant effect (INR 2-3).
Before the forthcoming surgical intervention (at a high risk of thromboembolic complications) treatment is started 2-3 days before the operation.
When prosthetic heart valves, acute venous thrombosis of veins or thromboembolism (in the initial stages), thrombosis of the left the ventricle and for the prevention of myocardial ischemia, one must strive for an effective action, which is noted when MNO is 2.8-4.0.
In the case of acute thrombosis treatment is carried out in combination with heparin until the effect of oral anticoagulant therapy is fully manifested (not earlier than 3-5 days of treatment).
When joint use of warfarin with ASA, the INR should be within the range of 2-2.5.

Older patients and weakened patients are usually prescribed a drug in lower doses.

The duration of treatment depends on the patient's condition. Treatment can be canceled immediately.

Side effects

In some cases, the use of Warfarin can provoke the development of undesirable side effects from various body systems. Namely:

jaundice;
rash;
hives;
itching;
diarrhea;
eosinophilia;
eczema;
necrosis of the skin;
vasculitis;
hair loss;
nephritis;
urolithiasis;
bleeding;
increased sensitivity to warfarin after prolonged use;
anemia;
nausea, vomiting;
abdominal pain;
tubular necrosis;

Reactions of hypersensitivity, manifested in the form of skin rashes, and characterized by a reversible increase in concentration liver enzymes, cholestatic hepatitis, vasculitis, priapism, reversible alopecia and calcification of the trachea.

Overdose

Symptoms of chronic intoxication with an overdose of warfarin are the presence of blood veins in urine and feces, bleeding from the nose or gums, hemorrhages in the skin, excessive bleeding during menstruation, severe and prolonged bleeding with minor damage to the epidermis.

If prothrombin time exceeds 5% and other possible sources of bleeding (nephrourolythiasis, etc.) are absent, correction of the dosing regimen is not necessary. With minor bleeding, the dose of Warfarin is reduced or canceled for a short time. If a patient develops heavy bleeding, he is prescribed vitamin K until the coagulant activity is completely restored. Threatening bleeding is an indication for transfusion of freshly frozen plasma, fresh blood or concentrates of prothrombin complex factors.

special instructions

Before the beginning of therapy determine the indicator of INR (resp. Prothrombin time, taking into account the coefficient of sensitivity of thromboplastin). In the future, a regular (every 2-4-8 weeks) laboratory monitoring is carried out.
The use of almost any drug affects the absorption of Warfarin.
Do not take warfarin in patients with hereditary galactosemia, deficiency of the enzyme lactase, glucose-galactose malabsorption.
The action of the drug is enhanced with decompensated heart failure, fever, alcoholism with concomitant liver damage, hyperthyroidism. In hypothyroidism, on the contrary, the effect of its use can be reduced.

Treatment of elderly patients should be carried out with special precautions, since the synthesis of clotting factors and liver metabolism in such patients is reduced, resulting in an excessive effect of warfarin.

Drug Interactions

Diuretics can reduce the effect of anticoagulants (in the case of pronounced hypovolemic action, which can lead to an increase in the concentration of coagulation factors).
NSAIDs, dipyridamole, valproic acid, cytochrome P450 inhibitors (cimetidine, chloramphenicol) increase the risk of bleeding. Combined use of these drugs and warfarin should be avoided (cimetidine can be replaced with ranitidine or famotidine). If it is necessary to treat chloramphenicol, anticoagulant therapy should be temporarily discontinued.
The effects of warfarin are weakened by barbiturates, vitamin K, glutetimide, griseofulvin, dicloxacillin, carbamazepine, mianserin, paracetamol, retinoids, rifampicin, sucralfate, phenazone, colestyramine.
When using medicines (eg, laxatives), which may increase the risk of bleeding due to a decrease in normal coagulation (inhibition factors of blood coagulation or liver enzymes), the strategy of anticoagulant therapy should be determined by the possibility of conducting laboratory monitoring. If frequent laboratory monitoring is possible, then, if the need for therapy with such drugs, the dose of warfarin can be reduced by 5-10%. If laboratory monitoring is difficult, then if necessary, the administration of these drugs warfarin should be canceled.
The effects of warfarin strengthen allopurinol, amiodarone, anabolic steroids (alkylated at the C17 position), ASA and other NSAIDs, heparin, glibencamide, glucagon, danazol, diazopyramide, disulfiram, isoniazid, ketoconazole, clarithromycin, clofibrate, levamisole, metronidazole, miconazole, nalidixic acid, nilutamide, omeprazole, paroxetine, proguanil, oral hypoglycemic drugs - derivatives of sulfonamides, simvastatin, sulfonamides, tamoxifen, thyroxine, quinine, quinidine, fluvoxamine, fluconazole, fluorouracil, quinolones, chloral hydrate, chloramphenicol, cephalosporins, cimetidine, erythromycin, ethacrynic acid, ethanol. In the case of combined use of warfarin with the above drugs, it is necessary to monitor the INR at the beginning and at the end of treatment and, if possible, 2-3 weeks after the start of therapy.

Reviews

We picked up some of the people's feedback on Warfarin:

Alexander. I have been taking Warfarin for six months already. The matter is that at inspection in a hospital it was found out, that I have an arrhythmia. And this diagnosis contributes to the formation of blood clots. The doctor advised me to use anticoagulants. At first I was frightened by this name, and I took just aspirin to dilute the blood. But then I convinced myself that I had to try. I started with one tablet a day. A month later checked the blood in the clinic, it turned out that this dose suits me. The fact is that "Warfarin" is a strong anticoagulant and when overdosing, local bleeding is possible. So it's worth keeping a systematic monitoring of the blood test.
Lyudmila. The cardiologist prescribed warfarin, as there were attacks of atrial fibrillation, and the vascular doctor (I also have thrombophlebitis) does not prescribe warfarin. I'm afraid to start such treatment, it is impossible to do injections, but I have to resort to their help for the treatment of lumbar disease. I wonder if there is another drug that is not that complicated?
Tatyana. My brother does not take warfarin any more. Tomorrow is a funeral. Gastric mucosa and esophagus ruptures, massive bleeding, in the hospital failed. No doctor warned about his diet. He himself, like many patients, did not read the instructions for use and did not report to relatives about the prescribed medication. I think in our medicine this is a dangerous medicine. Judging by the reviews, no one has a guarantee from such an event. A similar case of my mother's friend - a husband lying sick after a hemorrhagic stroke and with a stomach ulcer. Warfarin.
Ilya. I had a heart attack a month and a half ago and had a heart attack. Took Warfarin Month. bleeding from the nose three times. I called an ambulance. Stopped taking warfarin, ASA. In a week I began to take it again. Let's go hematomas. Decreased the dose by half to 1.25 mg. The condition improved, there were fewer headaches, leg cramps. But MNO was 1.68, .89. I will try again warfarin , and ASK 100 mg.