Warfarin-OBL pills 2.5mg, 100pcs

Composition

For 1 tablet:

Active ingredient:

warfarin sodium clathrate-2.71 mg, in terms of warfarin sodium-2.5 mg;

excipients:

magnesium stearate,

lactose monohydrate,

corn starch,

calcium hydrophosphate dihydrate,

povidone K-30.

Pharmacological action

Warfarin c belongs to the group of anticoagulants-drugs that prevent blood clotting, and is intended for long-term use.

It has an indirect anticoagulant effect, inhibiting the synthesis of a number of factors involved in the regulation of blood clotting in the liver.

Warfarex prevents the formation of new blood clots and prevents the increase of already formed ones.

Indications

Treatment and prevention of thrombosis and embolism of blood vessels: acute venous thrombosis and pulmonary embolism; postoperative thrombosis; repeated myocardial infarction; as an additional tool for surgical or medical (thrombolytic) treatment of thrombosis, as well as for electrical cardioversion of atrial fibrillation; recurrent venous thrombosis; repeated pulmonary embolism; prosthetics of heart and vascular valves (possible combination with acetylsalicylic acid); thrombosis of peripheral, coronary and cerebral arteries; secondary prevention of thrombosis and thromboembolism after myocardial infarction and atrial fibrillation.

Contraindications

Hypersensitivity, acute bleeding, severe liver or kidney diseases, severe arterial hypertension, acute DIC syndrome, protein C and S deficiency, hemorrhagic diathesis, thrombocytopenia, acute gastric and duodenal ulcer, brain hemorrhage, alcoholism, renal failure, pregnancy, hereditary lactose intolerance, lactase deficiency, glucose-galactose malabsorption.

Side effects

Most common: >1/10 – bleeding.

Often: >1/100, >

Infrequently: >1/1,000, >

Rare: >1/10 000, >

Bleeding. The most common risk factor for intracranial hemorrhage. The likelihood of bleeding increases if the INR is significantly higher than the target level. If the bleeding started with an INR that is within the target level, then there are other concomitant conditions that need to be investigated.

From the digestive system. Vomiting, nausea, diarrhea.

Necrosis. Coumarin necrosis. In 90% of cases, necrosis develops in women. Lesions are observed from the 3rd to the 10th day of taking the drug and the etiology suggests a lack of antithrombotic protein C or S.

Palmar-plantar syndrome. A very rare complication in warfarin therapy, its development is typical for men with atherosclerotic diseases.

Other items. Hypersensitivity reactions that manifest as a skin rash and are characterized by a reversible increase in liver enzyme concentrations, cholestatic hepatitis, vasculitis, priapism, reversible alopecia and tracheal calcification. Independent risk factors for the development of serious bleeding during warfarin treatment are: old age, high intensity of concomitant anticoagulant and antiplatelet therapy, the presence of a history of strokes and gastrointestinal bleeding. The risk of bleeding is increased in patients with a CYP2C9 gene polymorphism.

Interaction

When used concomitantly with anticoagulants and drugs with antiplatelet activity, the risk of bleeding increases.

When used concomitantly with anticholinergic agents, memory and attention disorders may occur in elderly patients.

When used concomitantly with inhibitors of microsomal liver enzymes, the anticoagulant effect of warfarin increases and the risk of bleeding increases.

When used concomitantly with hypoglycemic agents, sulfonylurea derivatives may increase their hypoglycemic effect.

When used concomitantly, the anticoagulant effect of warfarin is reduced by: inducers of microsomal liver enzymes (including barbiturates, phenytoin, carbamazepine), glutetimide, griseofulvin, dicloxacillin, coenzyme Q10, mianserin, paracetamol, retinoids, rifampicin, sucralfate, phenazone, colestyramine, glutetimide, vitamin K, acitretin, diuretics (spironolactone and chlortalidone), aminoglutetimide, mercaptopurine, mitotan, cisapride, ginseng preparations, glucagon.

It is possible to increase the anticoagulant effect of warfarin and increase the risk of bleeding when used simultaneously with heparin, NSAIDs (including acetylsalicylic acid), pyrazolone derivatives (including phenylbutazone, sulfinpyrazone), tramadol, dextropropoxifene, a combination of paracetamol and codeine, antiarrhythmic agents (including amiodarone, quinidine, propafenone, moracizine), antimicrobial and antifungal agents (including those with chloramphenicol, metronidazole, cefamandol, cefmetazole, cefoperazone, cefazolin, erythromycin, azithromycin, roxithromycin, clarithromycin, co-trimoxazole, miconazole, ketoconazole, itraconazole, fluconazole, nalidixic acid, ciprofloxacin norfloxacin, ofloxacin, aminosalicylic acid, benzylpenicillin, doxycycline, isoniazid, neomycin, tetracyclines, aztreonam), glibenclamide, valproic acid, quinine, proguanil, cyclophosphamide, methotrexate, fluorouracil, with combinations of etoposide and vindesin or carboplatin, ifosfamide with mesna, tamoxifen, flutamide, interferon alpha (for chronic hepatitis C), interferon beta, saquinavir, clofibrate, ciprofibrate, fenofibrate, gemfibrozil, cimetidine, lovastatin, fluvastatin, simvastatin, piracetam, danazol, tramadol.

When used concomitantly with tricyclic antidepressants, disopyramide, felbamate, terbinafine, allopurinol, dipyridamole, chloral hydrate, ranitidine, ascorbic acid, tocopherol, data on drug interaction are ambiguous.

In patients with chronic alcoholism, taking disulfiram, an increase in the effects of warfarin was observed.

When used concomitantly with colestyramine, the absorption and bioavailability of warfarin decreases.

When used concomitantly with ticlopidine, cases of liver damage have been described. The anticoagulant effect of warfarin does not change.

When used concomitantly with phenazone, the concentration of warfarin in blood plasma decreases.

When used concomitantly with phenytoin, an initial increase in anticoagulant activity is reported, followed by a decrease in it.

When used concomitantly with fluoxetine, trazodone, vitamin E, there are reports of increased action of warfarin.

When used concomitantly with cyclosporine, there is a mutual decrease in the effects.

When used concomitantly with enoxacin, the clearance of the R-isomer decreases, but not the S-isomer, while the prothrombin time does not increase.

When used concomitantly with ethacric acid, the diuretic effect and hypokalemia may increase, since the concentration of free (active) ethacric acid increases as a result of competition for binding to plasma proteins.

With regular alcohol consumption, the effects of warfarin may be reduced, apparently due to the induction of liver enzymes. However, if the liver is damaged, the effects of warfarin may be enhanced.

If you accidentally take a large amount of alcohol, you may increase the effect of warfarin.

How to take, course of use and dosage

Inside, in one go, at the same time of day.

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

When determining INR, the sensitivity index of thromboplastin should be taken into account and this indicator should be used as a correction factor (1.22 – when using domestic thromboplastin from the brain of a rabbit “Neoplast” and 1.2 – when using a thromboplastin from the company “Roche Diagnostics”). Elderly and debilitated patients are usually prescribed lower doses of the drug.

Before the upcoming surgical intervention (with a high risk of thromboembolic complications), treatment begins 2-3 days before the operation.

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 prosthetics of heart valves, acute venous venous thrombosis or thromboembolism (at the initial stages), left ventricular thrombosis and for the prevention of myocardial ischemia, one should strive for effective action, which is noted at an INR of 2.8-4.

In the case of atrial fibrillation and during maintenance therapy for venous thrombosis and thromboembolism, a moderate anticoagulant effect is achieved (INR 2.8-3).

When warfarin is co-administered with acetylsalicylic acid, the INR should be in the range of 2-2.5.

Children

Data on the use of warfarin in children are limited. The initial dose is usually 0.2 mg / kg / day for normal liver function and 0.1 mg / kg / day for impaired liver function.The maintenance dose is selected in accordance with the INR values. Recommended INR levels are the same as for adults. The decision to prescribe vrfarin in children should be made by an experienced specialist. Treatment should be carried out under the supervision of a pediatrician.

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

Overdose

The indicator of treatment effectiveness is at the border of the development of bleeding, so the patient may have minor bleeding, for example, microhematuria, bleeding gums, etc. In mild cases, it is enough to reduce the dose of the drug or stop treatment for a short time. In case of minor bleeding, it is sufficient to stop taking the drug until the target INR level is reached.

In case of severe bleeding – use of vitamin K (intravenously) and activated carbon, coagulation factor concentrate or fresh frozen plasma. If oral anticoagulants are indicated for use in the future, it is necessary to avoid high doses of vitamin K, since warfarin resistance develops within 2 weeks.

After treatment, long-term monitoring of the patient is necessary, given that the half-life of warfarin is 20-60 hours.

Special instructions

A prerequisite for warfarin therapy is strict compliance with the prescribed dose of the drug.

Patients suffering from alcoholism, as well as patients with dementia, may not be able to follow the prescribed warfarin regimen. Conditions such as fever, hyperthyroidism, decompensated heart failure, alcoholism with concomitant liver damage may increase the effect of warfarin. In hypothyroidism, the effect of warfarin may be reduced. In the case of renal failure or nephrotic syndrome, the level of the free fraction of warfarin in the blood plasma increases, which, depending on concomitant diseases, can lead to both an increase and a decrease in the effect. In the case of moderate hepatic insufficiency, the effect of warfarin is enhanced. In all of the above conditions, MHO levels should be carefully monitored.

Patients receiving warfarin are advised to take paracetamol, tramadol, or opiates as painkillers. If a rapid antithrombotic effect is needed, it is recommended to start treatment with heparin; then, for 5-7 days, a combination therapy with heparin and warfarin should be carried out until the target MHO level is maintained for 2 days. To avoid coumarin necrosis, patients with hereditary antithrombotic protein C or S deficiency should first be given heparin. The concomitant initial loading dose should not exceed 5 mg. use of heparin should continue for 5-7 days.

During treatment with warfarin, it is necessary to refrain from using ethanol (risk of hypoprothrombinemia and bleeding).

In the case of individual warfarin resistance (rare),5 to 20 shock doses of warfarin are necessary to achieve a therapeutic effect.

If taking warfarin in such patients is ineffective, other possible causes should be identified, including: simultaneous use of warfarin with other drugs (see the corresponding section of the instructions), inadequate nutrition, laboratory errors.

Treatment of elderly patients should be carried out with special precautions, since the synthesis of clotting factors and hepatic metabolism in such patients decreases, as a result of which an excessive effect of warfarin may occur.

Form of production

Tablets

Active ingredient

Warfarin

Conditions of release from pharmacies

By prescription

Dosage form

Tablets

Purpose

Nursing mothers as prescribed by a doctor, For adults as prescribed by a doctor

Indications

Prevention of heart attacks and strokes, Prevention of thrombosis, Myocardial infarction