Tamoxifen

Tamoxifen is an antiestrogenic drug that has anti-tumor properties.

Indications Tamoxifen

It is shown to be used for treatment of estrogen-dependent breast cancer (for women, especially those who entered the menopause period) or gynecomastia of the mammary glands in men. Also, the drug can be used in the treatment of cancer of the following organs: endometrium or ovaries, as well as kidneys. And besides this, melanomas, sarcomas (affecting soft tissues) that occur when there are estrogen receptors in the tumor. The medicine can be used to eliminate prostate cancer in case of resistance of the organism to other drugs.

[1], [2], [3],

Release form

Produced in the form of tablets. One blister plate contains 10 tab. The bundle can have 1, 3 or 10 blisters.

[4], [5], [6], [7], [8], [9]

Pharmacodynamics

The action of Tamoxifen is based on its properties, which allow to interfere with the activity of estrogen receptors. Tamoxifen, along with individual metabolites, fights with E2 beyond the areas of connection with cytoplasmic estrogenic conductors in the cells of the uterus and mammary glands, and in addition to the adenohypophysis and the vagina. In addition, it exerts its influence in tumors containing an increased amount of estrogenic conductors. Unlike the conductive estrogen complex, the identical tamoxifen complex does not provoke the process of DNA synthesis inside the nucleus. Instead, it suppresses cell division, resulting in tumor cells beginning to regress and subsequently die.

[10], [11], [12]

Pharmacokinetics

After oral administration tamoxifen is rapidly absorbed, reaching a peak concentration in blood serum 4-7 hours after the use of a single dose. The index of equilibrium concentration in the blood serum tamoxifen generally reaches 3-4 weeks after taking the medication. With plasma proteins binds to 99%. Metabolism, in which the products of decomposition are formed, occurs in the liver.

The active substance is withdrawn in 2 separate phases. The initial half-life is 7-14 hours, and the subsequent period is a slow terminal and lasts 7 days. It is excreted mainly with feces in the form of conjugates. The remaining small part of the medicine is excreted from the body with urine.

[13], [14], [15], [16], [17]

Dosing and administration

The dose is usually prescribed individually, it depends on the indications. The daily dosage is 20-40 mg, it is recommended to take 20 mg of medication every day for a long period of time. If symptoms of disease progression appear, you should cancel the medication.

Tablets should be swallowed without chewing, and then washed down with water. You can drink medicine for 1 reception in the morning, or divide the daily dosage by 2 times, and drink in the morning and in the evenings.

[23], [24], [25], [26], [27], [28], [29]

Use Tamoxifen during pregnancy

During gestation, Tamoxifen should not be consumed.

Contraindications

Among other contraindications:

• period of breastfeeding;
• hypersensitivity to the active ingredient or other substances contained in the drug.

Care should be taken when prescribing for diabetes, and in addition to kidney failure, eye diseases (such as cataracts), DVT, thromboembolism (including history). In addition, with hypercalcemia and hyperlipidemia, thrombocytopenia and leukopenia, and in the case of combination with treatment with indirect anticoagulants.

[18]

Side effects Tamoxifen

Among the side reactions to taking medication:

• Organs of the circulatory system: leuko- or thrombocytopenia may develop (the level of platelets often decreases to 80-90x10 9 / l). In rare cases, there may be pancyto-or neutropenia.
• Organs of the endocrine system: severe vaginal bleeding or discharge, "hot flashes", disorders of the menstrual cycle, severe genital itching. Treatment with tamoxifen increases the risk of productive changes in the endometrial area - endometriosis may develop, and in addition to it, polyps or hyperplasia, and in some cases even cancer. At the premenopausal stage, menstruation may stop in women, and in some situations reversible serous puffiness in the ovaries arises. In men, a loss of libido or impotence may occur.
• Gastrointestinal organs: vomiting and nausea. In isolated cases - a disorder in the work of taste buds, anorexia, diarrhea or constipation.
• Organs of vision: loss of visual acuity, occurrence of retinopathy or cataract, corneal opacity.
• Organs of the digestive system: the drug is able to affect the lipid spectrum in the blood serum. Occasionally, hypertriglyceridemia is observed, in some cases with the development of pancreatitis. Treatment with tamoxifen increases the number of hepatic enzymes and can sometimes cause more severe disorders (eg, cholestasis, fatty hepatitis or hepatitis).
• Reactions of the skin and its derivatives: rash, baldness, or vice versa, accelerated hair growth.
• Hypersensitivity: Quincke edema, erythema multiforme, malignant exudative erythema, parapemphigus.
• Organs of the vascular system: most often there are thromboses, and in some rare cases - PE.

[19], [20], [21], [22]

Interactions with other drugs

In the case of combined admission with cytostatics, the risk of blood clots increases.

Antacid drugs, H2-blockers, as well as other agents with this type of influence, increase the pH in the stomach, so that the tablet dissolved in the intestine can dissolve prematurely, and thus lose its protective properties. Therefore, it is necessary to take breaks in 1-2 hours between taking such drugs and tamoxifen.

There is evidence that Tamoxifen enhances the anticoagulant effect of coumarin medicines (eg, warfarin).

Drugs that reduce the rate of excretion of calcium (eg, thiazide diuretics), are able in combination with tamoxifen to increase the risk of hypercalcemia.

The combination of tamoxifen and tegafur can provoke the development of cirrhosis of the liver or hepatitis in a chronic form.

With simultaneous administration of Tamoxifen and other hormonal drugs (especially contraceptives that contain estrogen), the specific effects of both drugs are weakened.

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Storage conditions

The medicine is required to be kept in a place that is closed from the sun, dry place, which is inaccessible to children. Temperature regime - no more than 25 ° C.

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Shelf life

Tamoxifen may be used for 3 years from the date of manufacture.

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