Various vascular diseases are the most common ailments of our time, which need urgent correction by serious medications. In some cases, such medicines are sold strictly by prescription. “Warfarin” (in Latin the name of the drug is spelled Warfarin) is a strictly prescription drug. It can be used only as directed by a doctor. Although the pharmacies of our country ask for medication quite often, it is almost impossible to purchase Warfarin without a prescription. This is due to the fact that the medicine has an impressive spectrum of side effects and contraindications. However, more on that later. The article will detail the instructions for “Warfarin”, analogues and reviews about the drug.
At a specialist appointment
Before prescribing this medication, the doctor must prescribe the “Warfarin” prescription in Latin. It is with such a document, certified by the seal, that you should go to the pharmacy and purchase the medicine.
However, first you need to carefully listen to the recommendations and warnings of the attending doctor so that taking the drug is not harmful, but beneficial. Only strictly adhering to the dosage and other appointments of a specialist, you can achieve success in using this tool to treat your ailments.
What does the “Warfarin” prescription look like in Latin tablets? Most likely, the entry will look like this: Tab. Warfarini 0.0025. What does this mean? This recipe “Warfarin” (in Latin) indicates the active substance of the drug, its release form, as well as the dosage. Among other recommendations, the doctor will prescribe a medication schedule.
Briefly about the composition of the drug
So, we found out if you need a prescription for Warfarin. What is remarkable about this drug? The thing is that the active ingredient of the drug is sodium warfarin (which is an indirect anticoagulant), which dilutes the blood and slows down its coagulation. We will talk about the pharmacological action of this component in more detail below.
The composition of the tablets, in addition to the active substance, includes other ingredients. In one pill, in addition to 2.5 milligrams of warfarin sodium, 50 milligrams of lactose are contained, as well as corn starch, calcium hydrogen phosphate dihydrate, magnesium stearate, indigo carmine, povidone 30.
What is a medicine? These are light blue rounded tablets with crosswise scoring applied for convenient division of the pill.
Pharmacological action of the drug
The medicine “Warfarin”, as mentioned above, is used to thin the blood. What affects the slowdown of the coagulation process? First of all, the active component blocks the synthesis of vitamin K and K-dependent factors necessary for blood coagulation. First of all, these are factors II (prothrombin), VII (proconvertin), Christmas and Stuart-Prauer factors (IX and X, respectively). Due to this effect, the concentration of these components decreases, which slows down blood coagulation.
Pharmacokinetic features of the drug
According to the instructions for use, the medicine “Warfarin” is almost rapidly absorbed from the organs of the gastrointestinal tract. Its binding to plasma proteins is almost one hundred percent.
The metabolic process occurs in the liver. It is there that the substance breaks down into two isomers, which are split in different ways.
The medication begins to act on the second or third day after the first application. The maximum effect on the body is observed on the fifth or sixth day after the start of the drug. A few days after the end of the course (on the fourth or fifth day), the active component is excreted from the body and ceases to exert any influence on it. In this case, the half-life of the component is not more than one to three days.
The medicine is removed from the body in this way. Metabolized in the liver, “Warfarin” is reabsorbed in the organs of the gastrointestinal tract and excreted together with urine.
What illnesses justifies the use of such a serious drug?
Indications for the use of the drug
As mentioned above, the medication is used for serious pathologies of blood vessels. Most often, doctors prescribe “Warfarin” for recurrent or acute forms of venous thrombosis, as well as for pulmonary embolism. Cardiac ailments, such as myocardial infarction, strokes and ischemic attacks, are frequent indications for the use of the drug.
This medication is also actively used for preventive purposes to prevent the above diseases. Moreover, it is prescribed to patients who are diagnosed with heart valve lesions or atrial fibrillation, in order to prevent thromboembolic complications. To prevent such pathologies, tablets are also taken by people who have undergone prosthetic heart valves.
In some cases, the attending physician may consider it appropriate to prescribe Warfarin after surgery as a prophylaxis of thrombosis.
As you can see, indications for the use of the drug are serious pathologies and disorders of the cardiovascular system. In what cases can you not take pills?
Contraindications
What ailments are not recommended for use of the drug? First of all, tablets cannot be taken if the patient has an individual intolerance to any of the components that make up the medication.
In addition, the manufacturer does not strictly recommend the use of “Warfarin” for acute bleeding, as well as severe pathologies of the liver and kidneys. The following serious contraindications to the use of the drug include conditions such as DIC-syndrome of acute nature, thrombocytopenia, deficiency (shortage) of proteins S and C.
Moreover, tablets will not be recommended by a specialist if the patient is at risk of bleeding. This can be triggered by such pathological conditions as various hemorrhagic disorders, esophageal varicose veins, arterial aneurysms, duodenal ulcer or stomach ulcers, lumbar puncture, intracranial hemorrhage, malignant hypertension, severe wounds (including postoperative ones), bacterial endocarditis, hemorrhagic, and hemorrhagic.
Pregnancy, lactation and medication
Can I use the drug to treat pregnant patients? During the period of gestation, a woman is best to refrain from using this medication. It can be used only if the expected benefit to the mother exceeds the possible harm to the fetus.
According to the instructions, “Warfarin” is strictly contraindicated in the first three months, as well as in the last four weeks of pregnancy. This is due to the fact that the active substance can provoke bleeding during childbearing and during delivery. Moreover, the active component negatively affects the development of the fetus, causing it to deform the nasal cartilage, spine, hands. It is possible atrophy of the optic nerve, delayed physical or mental development, etc. Paying attention to this information, women of childbearing age should use effective methods of contraception during treatment with “Warfarin”.
According to the manufacturer's recommendations, the tablets can be used during breastfeeding, since the therapeutic dose of the drug should not have a serious pathological effect on the newborn. Nevertheless, many women decide to interrupt their lactation and transfer the baby to artificial feeding for the period of treatment with “Warfarin”.
Side effects from taking the drug
It is not surprising that such a serious potent agent can provoke the appearance of unwanted reactions. Most often this is due to individual intolerance to the drug or its improper use. For example, when the dosage of a medication was incorrectly prescribed, or its purpose was inappropriate.
What side effects can accompany the medication of interest to us? First of all, the use of “Warfarin” may be accompanied by bleeding of various organs, as well as vomiting, loose stools, and nausea. According to data, eight percent of patients taking the drug for a year have a different type of bleeding. Most often it is bleeding from the nose or gums, vaginal or subconjunctival, from the rectum or organs of the gastrointestinal tract. Intracranial or intracerebral hemorrhages, hematuria are less common. In some cases, the patient's condition may be so severe that urgent hospitalization or even a transfusion of blood or blood substitutes is required. Most often, this state of affairs is observed in elderly people or patients with a stroke or gastrointestinal bleeding in the anamnesis.
Quite rarely, taking the drug is accompanied by bruising on the skin, rash, itching, and hives. Sometimes such adverse events can trigger skin necrosis, which most often begins with a darkening of the epidermis and its swelling in the legs and buttocks. Such side effects often worry women five to ten days after the start of the course of pills.
In men, there is such an undesirable reaction of the body as the palmar-plantar syndrome, which manifests itself in burning pain and purple lesions of the epidermis on the fingers and feet. This condition worries representatives of the stronger sex, suffering from atherosclerotic diseases.
In some cases, a side effect of taking “Warfarin” may be increased activity of liver or jaundice enzymes, vasculitis or cholestatic hepatitis, eczema, or headache.
How should tablets be taken so that the course of therapy is beneficial and not harmful?
Recommendations regarding the use of the drug
The doctor will prescribe the detailed regimen and dosage, however, the instructions for use of “Warfarin” give general recommendations regarding its use.
Tablets should be taken once a day orally, washed down with a small amount of water. It is advisable that exactly 24 hours elapse between each appointment. The dosage of the drug and the duration of the coagulant course are prescribed by the attending physician. You can cancel the medication immediately.
According to the instructions and recommendations of medical specialists, before starting therapy, as well as during treatment (every four to eight weeks), an INR test must be taken. According to reviews, many patients are uncomfortable and hard to regularly conduct such blood tests, but this is very important during the period of treatment with “Warfarin”. INR monitoring should be carried out to regulate the required dosage of the drug. What kind of analysis is this and how does it affect the correction of the prescribed dosage? This can be read below.
Now you need to understand the general recommendations of specialists. According to the instructions, those patients who have not previously used the medication are prescribed five milligrams of the active substance per day for the first four days. Then you need to go through the above analysis. In accordance with the result, the doctor recommends a maintenance dose, which can vary between 2.5-7.5 milligrams per day.
If the patient has already used “Warfarin” earlier, then he is prescribed a drug in the amount of ten milligrams of the active substance for two days. Then, a maintenance dose of medication is prescribed for a person, after which an INR test is given and therapy is carried out in accordance with the obtained indicators.
Examination and its effect on dosage
As mentioned above, before and during treatment with “Warfarin”, it is necessary to take an analysis for INR. What kind of research is this?
This abbreviation stands for international normalized attitude. In simple terms, this is an indicator of the performance of the hemostasis system, which shows whether a person has a tendency to an increased occurrence of blood clots. Or, conversely, the patient is prone to a decrease in coagulability and frequent bleeding. The INR rate for a healthy person (regardless of gender) varies between 0.7 and 1.3.
In order to prevent or treat venous thrombosis, pulmonary embolism, dilated cardiomyopathy, atrial fibrillation, serious heart valve diseases or their prosthetics with bioprostheses, it is necessary to maintain an INR of 2-3 units. If the patient has prosthetics performed with mechanical prostheses or an acute myocardial infarction is diagnosed with a complicated form, then the INR should be slightly higher - 2.5-3.5.
Treating small patients
“Warfarin” is rarely used for treating children, but in some cases, a specialist may find it justified to appoint such a serious remedy to a child. For children, the dosage of the drug is calculated based on the body weight of the small patient. Recommended INR indicators are the same as for adults.
How to calculate the required dosage? Of course, the attending physician will recommend a more accurate appointment, but there is a general formula by which the drug can be prescribed. In this case, the initial daily dose of “Warfarin” should be 0.2 mg per 1 kg of the child’s weight. The maintenance dose is selected by the doctor based on the INR analysis indicators.
Below is a table that will show how to correctly calculate the dosage of a medication for the treatment of young children.
| INR level (days one through four) | Anticoagulant dosage |
| 1-1.3 | Repetition of the initial daily dose |
| 1.4-1.9 | Half of the initial dose |
| 2-3 | Half of the initial dose |
| 3.1-3.5 | Quarter of the initial dose |
| More than 3,5 | Stop using the medication. As soon as the INR level drops below 3.5, resume treatment using a dose of half the previous |
How to carry out maintenance therapy for small patients? In this case, everything will depend on the performance of a blood test for INR. The table below shows the possible dosage options.
| The value of INR (with maintenance therapy) | Dosage |
| 1-1.3 | Twenty percent dose increase |
| 1.4-1.9 | Ten percent dose increase |
| 2-3 | Dosage remains unchanged |
| 3.1-3.5 | Ten percent dose reduction |
| More than 3,5 | Stop using the medication. As soon as the INR level drops below 3.5, resume treatment using the dose, twenty percent less than the previous |
Other situations
Are there any restrictions when using the drug to treat elderly patients? According to the instructions for the medication, in this case there is no need to reduce the dosage of the active substance. However, patients over 65 years of age taking “Warfarin” should be closely monitored by specialists, as they are at increased risk of side effects.
And what about patients who suffer from various serious disorders in the liver? They also do not need to lower the dosage. However, treatment should be carried out under close monitoring of INR levels.
Regular analysis is also necessary for people suffering from various kidney dysfunctions. However, in this case, a dosage reduction of the active substance of the drug is also recommended. An individual treatment regimen should be prescribed by the attending doctor.
But what if a person who regularly takes Warfarin needs surgery? In such cases, it is recommended to stop taking the drug a few days before the operation. When to do it? Everything will depend on INR indicators:
- If the level of the analysis of interest to us is more than four units, then the anticoagulant is stopped five days before the operation.
- If INR indicators vary within three to four, then it is best to stop taking the medication three days before the manipulation.
- If the level of analysis of interest to us ranges between 2 and 3, then the doctor will recommend giving up the tablets two days before surgery.
A blood test is also necessary on the eve of the operation. If the INR level is greater than 1.8, then the patient should take 0.5 or 1 milligram of vitamin K 1 (the dosage is determined by the attending physician). .
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If the patient is deficient in protein C or S, then he should not be prescribed a loading dose of the drug. The course of treatment should begin with small doses of the active substance. This is necessary in order to avoid the possible development of skin necrosis.
There are situations when you need to quickly achieve the desired therapeutic effect. In this case, it is necessary to begin treatment with the introduction of a certain dose of heparin, and only then combine the use of this drug and “Warfarin”.
In rare cases, the patient may have individual resistance to warfarin sodium. Then the attending physician may consider it appropriate to increase the shock dose of the drug by five, or even twenty times.
What to do in case of overdose
Symptoms of such an unpleasant condition may be minor bleeding from the gums or the detection of blood in the urine. In this case, you must either reduce the dosage of the drug, or completely stop taking it. With a strong overdose, the doctor may consider it appropriate to administer vitamin K, a coagulation factor concentrate, or even plasma intravenously. Mandatory intake of activated carbon inside.
Interaction with other drugs
Many patients are interested in the compatibility of Warfarin with painkillers. According to the instructions, in the treatment of this drug should be used tramadol, paracetamol or opiates.
It is important to remember that the combined use of “Warfarin” and drugs that affect hemostasis and platelet count can trigger severe bleeding. Such prohibited drugs include acetylsalicylic acid, clopidogrel, dipyridamole, ticlopidine, NSAIDs (excluding COX-2 inhibitors), and high-dose penicillin antibiotics.
You should know that such medicines reduce the therapeutic effect of the drug we are interested in: “Colestyramine”, “Bozentan”, “Aprepitant”, “Mesalazine”, “Sucralfat”, “Griseofulvin”, “Dicloxacillin”, “Rifampicin”, “Nafsillin”, “ Colestyramine ”,“ Cyclosporin ”,“ Aminoglutetimide ”and others. This group of medicines also includes some antiviral, antidepressant, antiepileptic drugs, St. John's wort, ginseng, as well as foods rich in vitamin K (green vegetables and fruits, mint, olive oil, mustard, and so on).
However, there are substances that can enhance the effect of Warfarin, which may also be undesirable. These include medicines such as “Abciximab”, “Cimetidine”, “Glibenclamide”, “Omerpazole”, “Amiodarone”, “Digoxin”, “Dipyridamole”, “Sulfinpyrazone” and many others. It is also necessary to add some hypolipidemic and antifungal agents, steroid hormones and antibiotics of the macrolide group to this list.
Storage Tips
It is recommended to store Warfarin at a temperature not exceeding + 25 ° C for five years. It is best to keep the tablets in a dark place, inaccessible to children and animals.
Drug Substitutes
Among the analogues of the drug of interest to us in the active component, the first place is occupied by Warfarin Nycomed. Instructions for these tools are almost identical.
Below is a short list of substitutes for “Warfarin”, according to the pharmacological effects:
- “Phenylin”. The active ingredient is phenindione. The drug is available in tablets and is used to treat thrombosis, thrombophlebitis and complications caused by strokes, heart attacks, etc.
- “Sincumar”. The active substance of the tablets is acenocoumarol. This anticoagulant is used in the conditions described above.
- "Paradax." One capsule of the drug contains dabigatran etexilate in an amount of 150 milligrams. Most often, the medication is prescribed as a prophylaxis of venous and systemic thromboembolism , as well as stroke. It can be used for atrial fibrillation.
What people say about the drug
We examined in detail the instructions for use of "Warfarin" and analogues. Reviews of real patients about this tool are of interest to many.
Most people say that they are very satisfied with the drug. Most often, “Warfarin” is prescribed for various thromboses, less often for the prevention of strokes. Many patients take pills for life to prevent relapse, and according to their reviews, the disease no longer progresses.
However, many admit that taking the medication is accompanied by some side effects, such as severe itching of the epidermis, baldness. Often people bleed a little, have headaches.
Nevertheless, most patients with thrombosis agree that Warfarin is an inexpensive and effective drug that helps well if taken strictly in accordance with the doctor's recommendations. To many, he saved his life, and also improved the quality of life and health.
We disassembled the instructions for “Warfarin”. Reviews and analogues were also considered in the review.