Warfarex
Warfarex: instructions for use and reviews
- 1. Release form and composition
- 2. Pharmacological properties
- 3. Indications for use
- 4. Contraindications
- 5. Method of application and dosage
- 6. Side effects
- 7. Overdose
- 8. Special instructions
- 9. Application during pregnancy and lactation
- 10. Use in childhood
- 11. In case of impaired renal function
- 12. For violations of liver function
- 13. Drug interactions
- 14. Analogs
- 15. Terms and conditions of storage
- 16. Terms of dispensing from pharmacies
- 17. Reviews
- 18. Price in pharmacies
Latin name: Warfarex
ATX code: B01AA03
Active ingredient: warfarin (Warfarin)
Producer: Grindeks, JSC (Grindex, AO) (Latvia)
Description and photo update: 2019-11-07
Prices in pharmacies: from 21 rubles.
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Warfarex is an antithrombotic and anticoagulant drug. Vitamin K antagonist.
Release form and composition
Warfarex is available in the form of tablets of various dosages:
- tablets 1 mg: flat-cylindrical, round, beveled, white;
- tablets 3 mg: flat-cylindrical, round, with a beveled, blue color interspersed with a darker shade, on one side with a line;
- 5 mg tablets: flat-cylindrical, round, beveled, pink interspersed with a darker shade, on one side with a cross-shaped line.
The drug is packed in plastic bottles, tightly sealed with lids, 30 and 100 tablets each, one bottle in a cardboard box and instructions for using Warfarex.
Composition for one tablet:
- active ingredient: sodium warfarin (in the form of warfarin sodium clathrate) - 1, 3 or 5 mg;
- auxiliary components: magnesium stearate, microcrystalline cellulose, crospovidone, lactose monohydrate, indigo carmine (additionally for 3 mg tablets), crimson dye Ponso 4R (additionally for 5 mg tablets).
Pharmacological properties
Pharmacodynamics
Warfarex is an anticoagulant - a drug that prevents blood clotting. The drug is intended for long-term therapy. It has an indirect anticoagulant effect by inhibiting hepatic synthesis of several factors that are involved in the regulation of blood coagulation. Warfarin does not affect the already formed blood clots, but prevents their further increase, and also prevents the appearance of new blood clots.
Pharmacokinetics
The active substance of Warfarex is a racemic mixture of two stereoisomers - S and R, while the activity of the S stereoisomer is 2–5 times greater than that of the R stereoisomer, but the duration of its action is shorter.
Warfarin is completely absorbed in the digestive tract, reaching a maximum concentration in the blood approximately 4 hours after taking Warfarex. The therapeutic concentration of the substance in plasma is 0.003–0.015 mmol / l (1–5 μg / ml). Warfarin is 97–99% bound to plasma proteins.
It is metabolized in the liver to form inactive and inactive metabolites. Microsomal enzymes containing cytochrome P450 are involved in metabolism. A small amount of metabolites is excreted in the bile, the rest in the urine. About 8% of the dose taken is released unchanged. After a single oral administration, the half-life of warfarin is 20 to 60 hours (average 40 hours).
In elderly patients, the pharmacokinetics of Warfarex does not change significantly. It has been found that they are more sensitive to anticoagulants, but the nature of this phenomenon is unknown.
In patients with impaired liver function, the synthesis of blood clotting factors decreases, and the metabolism of the drug slows down, which enhances its inhibitory effect on the blood clotting process.
Indications for use
Warfarex is used for the treatment and prevention of diseases and conditions that arise as a result of blockage of blood vessels by blood clots, namely:
- myocardial infarction;
- deep vein thrombosis;
- atrial fibrillation;
- pulmonary thromboembolism;
- heart valve replacement.
Contraindications
Absolute:
- severe renal and / or hepatic impairment;
- severe arterial hypertension;
- obstructive (mechanical) jaundice;
- hemorrhagic diathesis;
- stroke;
- thrombocytopenia;
- acute disseminated intravascular coagulation;
- the threat of bleeding or existing bleeding in some serious illnesses;
- deficiency of coagulation proteins C and S;
- bacterial endocardial infection;
- exacerbation of peptic ulcer of the duodenum and stomach;
- chronic alcoholism;
- diabetes;
- the patient's age up to 18 years;
- period of pregnancy;
- upcoming or recently transferred complex diagnostic procedures and operations;
- the inability to adequately assess the state of the coagulation system using the available laboratory methods;
- hypersensitivity to the main or auxiliary components of the tablets.
Relative (Warfarex tablets are used with caution):
- mild to moderate chronic renal failure;
- moderate hepatic impairment;
- nephrotic syndrome;
- liver damage simultaneously with alcoholism;
- decompensated heart failure;
- hypo- or hyperthyroidism;
- fever;
- elderly age.
Warfarex, instructions for use: method and dosage
Warfarex tablets are taken orally, usually once a day, preferably at the same time.
The dose of warfarin, the frequency of administration and the duration of the course is determined by the doctor, taking into account the individual characteristics of the patient, the severity of the disease and the data of blood clotting tests (INR value - international normalized ratio). Do not change the dose prescribed by your doctor yourself.
As a rule, an initial dose of Warfarex of 5 mg or 2.5 mg per day is recommended. After 2 days, its increase is possible. By gradual selection (taking into account the patient's response and INR), an individual dose of the drug is established. After reaching the required INR value (usually 2–3, sometimes 3–4.5), the patient is transferred to maintenance therapy.
In elderly and debilitated patients, as well as those at risk, treatment with Warfarex is started with a lower initial dose and increased gradually, with extreme caution.
At the beginning of therapy, the INR is monitored daily, at 3-4 weeks of using Warfarex, the INR is determined 1-2 times a week, and after 1 month of treatment - once every 1-4 weeks. Additional INR control is required when the patient's health status changes, before a planned or emergency surgery or diagnostic procedure, and in the case of prescribing or discontinuing concomitant therapy drugs.
Side effects
- digestive system: rarely - abdominal pain, vomiting, nausea, jaundice, increased activity of liver enzymes, loose stools;
- cardiovascular system: isolated cases - circulatory disorders in internal organs or extremities (manifested by pain and dark red skin on the toes);
- blood coagulation system: often - hemorrhages in tissues and organs, bleeding;
- allergic reactions: dermatitis, pruritus, nettle rash;
- other reactions: general weakness, transient baldness, fever, changes in peripheral blood parameters.
Overdose
In case of an overdose of Warfarex, the patient may experience epistaxis, bleeding from the gums, hemorrhage into the skin. With small wounds of the skin, prolonged or severe bleeding is observed, and blood may be found in feces or urine. In women, excessive bleeding is noted during menstruation.
In cases where PTT (prothrombin time) is more than 5% and there are no other possible sources of bleeding (for example, urolithiasis), the dosage regimen is not adjusted. Minor bleeding requires dose reduction or short-term discontinuation of therapy. For severe bleeding, vitamin K is used until coagulation is fully restored.
special instructions
Anticoagulants increase the risk of bleeding. During treatment with the drug, the condition of the coagulation system should be regularly monitored.
With the simultaneous use of Warfarex with drugs that enhance its therapeutic effect, at the beginning, at the end and after 2-3 weeks from the start of therapy, it is necessary to periodically determine the INR value. The possibility of joint administration with drugs that increase the risk of bleeding due to a decrease in normal coagulant activity (for example, with inhibition of coagulation factors or a decrease in the activity of liver enzymes) is determined by the characteristics of laboratory control. If there is a possibility of frequent laboratory control, such drugs can be prescribed in conjunction with Warfarex, but reduce the dose of the latter by 5-10%. In situations where laboratory control is impossible or difficult, warfarin treatment should be discontinued.
The patient should inform the doctor about the occurrence of digestive disorders, accompanied by fever and diarrhea. When contacting pharmacists, dentists or doctors of other specialties, you must inform them about taking Warfarex. During treatment, work should be avoided associated with an increased risk of injury and, as a result, bleeding; it is necessary to handle dangerous and sharp objects with care. Do not take any dietary supplements or vitamins without consulting your doctor. The patient should receive a balanced diet and not dramatically change his character.
During therapy, it is recommended to refrain from drinking alcoholic beverages (due to the risk of hypoprothrombinemia).
Patients with lactose intolerance should take into account that one Warfarex tablet contains 106-112 mg of lactose.
Influence on the ability to drive vehicles and complex mechanisms
There is no information on the adverse effect of warfarin on human psychomotor functions.
Application during pregnancy and lactation
Warfarex is contraindicated in pregnant women. Patients of reproductive age during the period of drug treatment should use reliable and effective contraception.
The release of warfarin in breast milk is insignificant, therefore, Warfarex is allowed to be used during lactation, however, in the first few days of treatment, it is recommended to refrain from breastfeeding.
Pediatric use
Warfarex should not be used in patients under 18 years of age, since the safety of its use in children and adolescents has not been adequately studied in clinical studies.
With impaired renal function
Warfarin should not be given to patients with severe renal impairment.
In chronic renal failure of mild to moderate severity, as well as nephrotic syndrome, Warfarex is used with caution.
For violations of liver function
Warfarex is contraindicated in patients with severe hepatic impairment.
With moderate liver failure and liver damage (in patients with alcoholism), the drug is used with caution.
Drug interactions
Allopurinol, amiodarone, heparin, acetylsalicylic acid and other non-steroidal anti-inflammatory drugs, anabolic steroids, glucagon, diazoxide, glibenclamide, danazol, disopyramide, isoniazid, disulfiram, clarithromycin, levamisole, microfluoric acid, naphtha, omeprazole, proguanil, sulfonamides, thyroxine, quinidine, fluconazole, quinolones, chloramphenicol, cimetidine, ethacrynic acid, hypoglycemic drugs (sulfonylurea derivatives), tamoxifen, quinine, fluvoxamine, fluorouracil, etheralhydrochloride action.
Valproic acid, non-steroidal anti-inflammatory drugs, chloramphenicol, dipyridamole, laxatives, cimetidine and inhibitors of cytochrome P450 isoenzymes increase the risk of bleeding, so it is advisable to avoid the simultaneous use of Warfarex with the listed drugs.
Under the influence of diuretics, a decrease in the anticoagulant activity of warfarin is possible, since the pronounced hypovolemic effect of diuretics can lead to an increase in the content of blood coagulation factors.
Barbiturates, griseofulvin, carbamazepine, paracetamol, rifampicin, phenazone, vitamin K, dicloxacillin, mianserin, retinoids, sucralfate, cholestyramine, glutethimide weaken the effect of the drug.
Foods high in vitamin K (broccoli, spinach, lettuce, and other leafy vegetables) can reduce the anticoagulant effect of warfarin.
The effect of the drug may decrease in patients who smoke.
Analogs
Warfarex analogs are Marevan, Warfarin-OBL, Warfarin Nycomed, Sinkumar, Fenilin, etc.
Terms and conditions of storage
Keep out of the reach of children. Store in a dark place at a temperature not exceeding 25 ° C.
Shelf life is 2 years.
Terms of dispensing from pharmacies
Dispensed by prescription.
Reviews about Warfarex
There are very few reviews of Warfarex. In the available rare reports, patients share both positive and negative experiences with the drug. The drug prevents the formation of blood clots, helps to normalize blood pressure, but for some patients this anticoagulant did not fit and did not help to increase the INR value.
Price for Warfarex in pharmacies
Tablets 3 mg in vials of 100 pcs. you can buy for 100-110 rubles. The price of Warfarex 5 mg (100 tablets in vials) is 170-175 rubles.
Warfarex: prices in online pharmacies
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Drug name Price Pharmacy |
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Warfarex 5 mg tablets 100 pcs. RUB 21 Buy |
Maria Kulkes Medical journalist About the author
Education: First Moscow State Medical University named after I. M. Sechenov, specialty "General Medicine".
Information about the drug is generalized, provided for informational purposes only and does not replace the official instructions. Self-medication is hazardous to health!
