Warfarin is a drug from the group of vitamin K antagonists, which is an indirect anticoagulant (that is, a substance that promotes blood thinning).
Release form and composition
The drug is produced in the form of tablets, which include:
- 2.5 mg warfarin sodium;
- Excipients: Povidone 30, Indigo Carmine, Calcium Hydrogen Phosphate Dihydrate, Corn Starch, Lactose, Magnesium Stearate.
Indications for use
The use of warfarin is appropriate for the treatment and prevention of thrombosis (the pathological process, accompanied by the formation of blood clots in the vessels) and embolism (acute blockage) of the blood vessels of the circulatory system:
- Postoperative thrombosis;
- Acute venous thrombosis;
- Pulmonary embolism;
- Repeated myocardial infarction (MI).
As a supplement to the main therapy, warfarin, according to the instructions, can be applied:
- When conducting medical thrombolytic therapy, as well as the need for surgical treatment of thrombosis;
- When conducting electric pulse therapy of atrial fibrillation (in particular, electrical cardioversion);
- With recurrent vein thrombosis;
- With repeated pulmonary embolism;
- During surgery for prosthetic heart valves and blood vessels (warfarin may be prescribed in combination with acetylsalicylic acid);
- For the secondary prevention of thrombosis and vascular occlusion with a thrombus after myocardial infarction and atrial fibrillation (atrial fibrillation);
- With thrombosis of the coronary, peripheral and cerebral arteries.
According to the annotations to the drug, contraindications to the use of warfarin are:
- Diseases and conditions associated with an increased risk of bleeding;
- Pathological changes in the structure of the blood;
- Postponed in the recent past, neurosurgical operations;
- Extensive surgery for injuries that are characterized by a large area of damage;
- Ophthalmic surgery;
- Predisposition to bleeding in ulcerative lesions of the digestive system organs, in diseases of the urogenital or respiratory tract;
- Cerebrovascular hemorrhage;
- Pericarditis (inflammation of the outer lining of the heart);
- Aneurysm (significant expansion of the lumen of a blood vessel due to pathological changes in its walls);
- Bacterial endocarditis (inflammation of the inner lining of the heart of microbial etiology);
- Exudative (effusion) pericarditis;
- Severe damage to the liver and / or kidneys;
- Severe hypertension;
- Acute thrombohemorrhagic syndrome;
- The threat of termination of pregnancy;
- Inadequate patient monitoring laboratory conditions;
- Alcohol addiction;
- Lack of proper monitoring of elderly patients;
- Painful mental disorders that are accompanied by behavioral disorders and inadequate perception of the surrounding reality;
- Disorder of the patient;
- The need for diagnostic procedures (eg, spinal puncture), which can potentially be accompanied by the development of uncontrolled bleeding;
- Carrying out a blockade, regional anesthesia of a wide area of the body;
- Malignant arterial hypertension.
Method of use and dosage
In accordance with the instructions for warfarin, the dosing regimen and the duration of the course of treatment are determined individually, depending on the parameters of blood coagulation, the patient's response to therapy, the characteristics of the clinical situation. On the selection of the optimal dosage takes, as a rule, from two weeks to two months. In this case, the daily dose ranges from 2 to 10 mg. To achieve a pronounced effect, taking the drug continues from six months to a year.
Treatment with warfarin is supplemented by the appointment of a special diet based on the principles of healthy eating.
According to the instructions, taking the drug may be accompanied by the development of hypersensitivity reactions, which manifest as skin rashes, as well as cholestatic hepatitis, vasculitis, a reversible increase in the concentration of liver enzymes, priapism, reversible alopecia (hair loss) and tracheal calcification.
In addition, against the background of the use of warfarin may be noted:
- Nosebleeds and bleeding gums;
- Increased sensitivity to warfarin after long-term drug treatment;
- Black tarry stools;
- Nausea, vomiting;
- Abdominal pain;
- Skin necrosis;
- Tubular (tubular) necrosis;
- A causeless occurrence of bruises and swellings in various parts of the body, as well as spots in the thighs, on the mammary glands or on the abdomen.
The use of virtually any drug affects the absorption performance of warfarin.
The effect of the drug increases with decompensated heart failure, fever, alcoholism with concomitant liver damage, hyperthyroidism. In hypothyroidism, on the contrary, the effect of its use can be reduced.
Patients who are undergoing treatment with this drug are recommended to prescribe opiates (opium alkaloids), tramadol or paracetamol as analgesics.
Warfarin should not be taken in patients with hereditary galactosemia, a deficiency of the enzyme lactase, glucose-galactose malabsorption.
Due to the lack of data on the safety of the use of drugs in pediatrics, the drug is not prescribed to patients younger than 18 years.
Generics (structural analogues) of Warfarin: Varfereks, Marevan, Warfarin Nycomed.
Analogs on the mechanism of action: Neodikumarin, Fenilin, Sinkumar, Phepromaron.
Terms and conditions of storage
Warfarin should be stored at room temperature in a dry, dark place. Its shelf life is 5 years.