Tamoxifen tablets 20 mg 30. What are the side effects of tamoxifen and why are they dangerous. Contraindications for medical use

Hormonal agents with antiestrogen action are used in oncology for the treatment of hormone-sensitive tumors. In bodybuilding, they are used to suppress the synthesis of female sex hormones with a high intake of androgens.

Other names and classification

The drug is classified as an estrogen antagonist.

Russian name

Tamoxifen

Latin name

Trade names

On sale there is a drug with the following names:

• Nolvadex;
• Istubal;
• Valodex;
• Tamofen.

CAS code

Composition and dosage forms of Tamoxifen

Available in the form of tablets with a dosage of 10 mg of tamoxifen citrate. Some manufacturers increase the concentration of the active substance to 20, 30 or 40 mg. Additional substances give the form of a tablet.

Pharmacological group

Anticancer agent, antiestrogen.

Pharmacological action of Tamoxifen

It is not a steroid, but may exhibit weak estrogen properties. In target organs, it binds competitively to estrogen receptors. These bodies are:

• breast;
• pituitary;
• uterus;
• vaginal tissues.

The antitumor effect is also based on the blocking of estrogen receptors in carcinoma. The drug, after connecting with the active center, does not stimulate DNA synthesis, as it normally does, but inhibits cell division. This inhibits the growth of the tumor and causes its gradual death.

The blocking effect on estrogens persists for several weeks after a single dose.

In women with menstrual irregularities, it can induce ovulation by acting on the hypothalamus and stimulating the hypothalamic releasing factor, which acts on the pituitary gland and causes the release of appropriate hormones.

In men, the use of the substance leads to an increase in the blood of luteinizing and follicle-stimulating hormones, which accelerate the production of spermatozoa. This effect is used in oligospermia. At the same time, the concentration of testosterone in the blood serum increases. This effect is used in bodybuilding to prevent the conversion of androgens into female sex hormones.

The tablet taken orally is well absorbed. The maximum effect develops after 4-7 hours. A constant equilibrium concentration of a substance in the blood is maintained with a 3-4-week regular intake.

Metabolism takes place in the liver. The half-life of the active substance is 7-14 hours, but the terminal metabolites leave the body no earlier than a week later. The bulk is excreted with feces.

Indications for the use of Tamoxifen

The main purpose of the drug is the treatment of oncological diseases:

• mammary cancer;
• carcinoma in situ of the milk duct;
• endometrial cancer;
• ovarian tumors.

It is used to treat breast carcinoma, including in men after castration, in postmenopausal women.

For men, it is used in the treatment of prostate cancer, prostatitis and glandular adenoma. Estrogen receptors have prostate tumors, so the choice of the drug is justified.

In bodybuilding, it is taken for anti-estrogen action and to reduce side effects after taking testosterone preparations.

How to use?

Admission rules are set individually depending on the indications for use.

Before meals or after?

Tablets are taken 1 time in the morning with meals, do not chew and drink plenty of water. You can divide the dosage into 2 doses - in the morning and in the evening.

In bodybuilding

Assign after a course of steroids in combination with aromatase inhibitors, such as Proviron. Tablets are taken orally daily. The first pill is taken a week before the end of the testosterone cycle, and the last one is taken 2 weeks after the end of the male hormones.

Dosage

The required number of tablets is selected individually depending on the indications. The standard dose is 20 mg. But the doctor can adjust the dose and treatment regimen.

In bodybuilding, the dosage is 10-20 mg.

special instructions

During cancer treatment, women should see a doctor regularly. If bleeding or spotting appears from the vagina, then the course is stopped. With caution are treated with mastopathy. In women with bone metastases, it is necessary to periodically determine the concentration of calcium in the blood serum. With the appearance of pronounced deviations from the norm, the drug should be discontinued.

There is a high risk of ovulation and pregnancy, so while taking the medicine, you must use any non-hormonal methods for contraception: a condom, an intrauterine device, spermicides.

In order to timely identify the toxic effect of the drug, it is necessary to control the general blood test, coagulability, calcium levels, cholesterol and triglycerides, liver enzymes. Sometimes it affects the normal functioning of the liver.

During pregnancy and lactation

It is forbidden to use the drug for pregnant and lactating women.

For impaired renal function

It is prescribed with caution in renal pathologies leading to a violation of their function.

Adverse reactions

Undesirable reactions are associated with a direct antiestrogenic effect. In women, there are signs that are characteristic of a lack of sex hormones:

• hot flashes;
• sweating;
• feeling of heat;
• headache;
• vaginal spotting;
• alopecia.

In the presence of metastases in the bones, pain appears in the region of the foci. Nausea, vomiting, abdominal pain and dizziness are rarely observed. With a predisposition, changes in the cornea, cataracts, retinopathy may occur. The action on the nervous system leads to the appearance of confusion, depressive disorder, fever.

At the beginning of cancer therapy, there may be a short-term deterioration in the condition and progression of the disease, which resolves within 2 weeks.

Antiestrogens increase the risk of developing thrombophlebitis and thrombosis. Liver enzymes are rarely elevated, and even more rarely severe liver damage occurs.

An estrogen antagonist can cause menstrual irregularities. With prolonged treatment, amenorrhea develops. In some women, there is a change in the structure of the endometrium towards hyperplasia, polyps, fibromas. Occasionally, endometrial cancer has been reported.

In men, the drug can lead to the following reactions:

• baldness;
• decreased erection;
• increased fatigue;
• gynecomastia;
• anorexia.

Other signs may be similar to those of women.

Contraindications

Do not use the drug in the presence of hypersensitivity or intolerance to any component of the drug. Contraindications are:

• kidney disease;
• diabetes;
• thrombophlebitis and thrombophilia;
• pregnancy and lactation;
• childhood.

Overdose

There are no data on cases of acute overdose. It is assumed that if the recommended doses are exceeded for a long time, the negative effects and side effects of the drug may increase. There is no specific antidote. Therefore, treatment is carried out depending on the symptoms that appear.

If patients are prescribed Tamoxifen, side effects may occur with different symptoms and consequences. This applies to cases if the drug is taken by women or men during bodybuilding. It is strictly forbidden to take such medicine on your own.

Features of the drug

The drug is available in the form of tablets for oral administration. It belongs to the group of anticancer drugs that suppress the production of estrogen. This is a female hormone, but it is also produced in a small amount in the male body. Since the amount of such a hormone in the blood can increase during bodybuilding in men, Tamoxifen effectively fights disorders.

The main active ingredient is tamoxifen citrate salt. The action is strong enough. The medicine itself can cause side effects even when used correctly, as indicated by the instructions for use.

Therefore, the intake of such a potent medication should occur only as directed by a doctor, in some cases - and under his careful supervision. The patient is also required to strictly adhere to the dosage regimen. For both women and men, it is selected only on an individual basis, depending on the severity of symptoms and other changes in the body.

Sometimes in parallel with this drug, the use of aromatase inhibitors is indicated.

action in bodybuilding

When using such a drug during sports, Tamoxifen has the effect of:

1. Increases power performance.
2. Increases hardness and relief of muscles.
3. Promotes a rapid and pronounced increase in muscle mass.
4. It has a pronounced antiestrogenic effect.
5. Fights fat deposits, helps to reduce fat mass.
6. Prevents the phenomena of feminization.
7. Reduces the risk of developing atherosclerosis.
8. Improves liver function.

Effect on the female body

This medicine blocks the activation by female sex hormones of cancer target cells (they are located in the glandular tissue of the breast). It is an estrogen hormone antagonist. In the uterus, it enhances the activity of female estrogens.

This explains why this drug is prescribed for the prevention and treatment of breast cancer in women.

In women, side effects from treatment with this medicine may include:

1. Cancer of the uterus. It has been proven that the active substance of this drug can increase the risk of endometrial cancer. The reason lies in the fact that Tamoxifen has the ability to activate the growth of this drug. It is especially dangerous to drink such pills for women suffering from breast cancer.
2. Endometriosis. This is a benign growth of the lining of the uterus. Regardless of the stage of the disease, Tamoxifen is able to exacerbate its course.
3. There are studies that show that this drug can cause uterine sarcoma- 1% of cases.
4. Women often have an increased risk fertility problems. Women taking Tamoxifen complain of infertility. Clinical data show that if the patient has a regular menstrual cycle, then after the end of taking such a drug, it is possible to become pregnant.
5. Hair thinning. This is due to the fact that the drug lowers the amount of the hormone estrogen, which indirectly affects the condition of the skin. It is recommended to use special varnishes that can save nails.
6. Some women report that when they started using Tamoxifen, they started memory problems.
7. Very rare and not always proven side effects of taking Tamoxifen include visual impairment. Most often this occurs if the patient has exceeded the recommended dose or self-medicated.
8. Liver cancer if a woman takes such a drug in large doses.
9. Long-term use of tamoxifen can cause phenomena masculinization among women. Characterized by the development of virilization, increased hair growth above the upper lip.

Side effect - thinning hair

Tamoxifen for men

Tamoxifen for men is used to treat gynecomastia. The peculiarity of such a drug is that it is neither androgenic nor anabolic. Tamoxifen solo also has an anti-estrogenic effect, so experts recommend taking such a remedy in bodybuilding and powerlifting.

Tamoxifen in bodybuilding is useful, but it can cause a number of side effects. Any athlete, especially a beginner, should know about them. Due to the antiestrogenic effect, the following undesirable effects are possible when taking this drug:

• sudden hot flashes;
• weight gain;
• violation of the composition of the blood;
• unpleasant itchy sensations in the perineum;
• hair loss, sometimes in the form of androgenetic alopecia;
• decrease in the severity of sexual desire, erectile dysfunction, in some cases - ejaculation disorders.
• disorders of bone tissue mineralization processes, which can contribute to the development of osteoporosis.

The advantage of such a medicine for men involved in sports is that it does not allow the appearance of the “gyno” effect (as gynecomastia is called in the language of bodybuilders). Very rarely, such unpleasant symptoms associated with taking Tamoxifen appear:

• dizziness, sometimes quite strong;
• nausea, aggravated in some cases to vomiting;
• an increase in body temperature to subfebrile values, sometimes even higher;
• increased daytime sleepiness;
• accumulation of fluid in the body, which leads to swelling;
• increased depression;
• sometimes loss of appetite up to anorexia;
• constipation;
• neuritis of the retrobulbar type;
• increased fatigue;
• the appearance of a pronounced rash on the skin;
• eye damage (retinopathy);
• clouding of the lens - cataract.

In very rare cases, patients may experience a violation of the normal functioning of the liver, gallbladder. Perhaps the development of cholestasis, acute hepatitis, clouding of consciousness up to its loss.

In a healthy male, long-term use of Tamoxifen can be harmful. The use of the drug for other purposes is strictly prohibited.

Tamoxifen for gynecomastia

This drug helps prevent the appearance of gynecomastia in men. This effect is achieved by the fact that the effect of estrogens is leveled in the representatives of the stronger sex, i.e. female sex hormones. Moreover, the drug can be taken regardless of the causes of the appearance of such a disease (for example, in adolescents, during the aging of the body).

Tamoxifen for gynecomastia in men is prescribed according to a strictly individual scheme. Today among doctors there is no single developed treatment regimen with this drug. Men need to pay attention to such nuances:

1. It is recommended to start treatment at any stage of pathology development. In this case, its effectiveness does not change. To avoid side effects, you need to carefully follow all the recommendations of the therapist.
2. It can also be prescribed for the prevention of gynecomastia.
3. If the disease is already formed, then you should drink this medicine daily. In advanced cases, the dosage can be slightly increased, and after reaching the desired effect, reduced.
4. The patient is forbidden to independently change the dose and regimen of the medication in order to avoid the development of side effects.

When not to take Tamoxifen

Under no circumstances should you use this medicine in the presence of such diseases and conditions:

• increased susceptibility to the active active ingredient;
• severe forms of thrombocytopenia (possible development of acute thrombosis and other dangerous pathologies);
• hypercalcemia (high levels of calcium in the blood);
• leukopenia (decrease in the number of white blood cells);
• diabetes of any type;
• pregnancy and lactation;
• severe kidney pathology;
• thromboembolic disorders;
• ophthalmic pathologies (the use of this medication is allowed only under the strict supervision of a physician).

Formula: C26H29NO, chemical name: (Z)-2--N,N-dimethylethanamine (as citrate).
Pharmacological group: antitumor agents/antitumor hormonal agents and hormone antagonists; hormones and their antagonists / estrogens, gestagens; their homologues and antagonists.
Pharmachologic effect: antitumor, antiestrogen.

Pharmacological properties

Tamoxifen binds (competitively) in target organs with estrogen receptors, just like estrogens, it is transferred to the nucleus of the tumor cell along with the receptor and thus blocks the action of estrogen. Tamoxifen in the gastrointestinal tract is well absorbed, the maximum plasma concentration is reached after 4-7 hours, the time to reach Css is 3-4 weeks. Tamoxifen is 99% bound to plasma proteins. It is metabolized in the liver by demethylation and hydroxylation. The elimination of tamoxifen has 2 phases: the initial half-life is 7-14 hours, followed by a terminal half-life of 7 days. Tamoxifen is excreted mainly in the form of metabolites through the intestines, excreted by the kidneys in small quantities.

Indications

Breast cancer: especially in men after castration, in women in menopause, carcinoma in situ of the duct of the breast; adjuvant treatment of breast cancer; endometrial cancer; estrogen-sensitive tumors.

Method of application of tamoxifen and dose

Tamoxifen is taken orally (regardless of the meal). The dosage regimen, depending on the indications, is set individually. Breast cancer - 1-2 times a day, 20-40 mg, endometrial cancer - 1-2 times a day, 20-30 mg. The maximum daily dose is 40 mg. Therapy is carried out until signs of regression of the process appear (for a long time).

Before starting tamoxifen therapy, women should undergo a thorough gynecological examination. Tamoxifen causes ovulation, which increases the likelihood of pregnancy, so women of reproductive age should use reliable non-hormonal methods of contraception during treatment and for 3 months after its completion. The use of tamoxifen should be discontinued in case of vaginal bleeding or the appearance of vaginal spotting, signs of thromboembolism of the branches of the pulmonary artery (shortness of breath), thrombosis of the veins of the lower extremities (swelling or pain in the legs). During therapy, it is necessary to monitor the blood picture (platelets, leukocytes), blood coagulation parameters and the functional state of the liver. Before and periodically during treatment, an ophthalmological examination is necessary. In patients with bone metastases at the beginning of therapy, it is necessary to determine the content of calcium in the blood serum (with severe hypercalcemia, the use of tamoxifen should be temporarily stopped). In patients with hyperlipidemia during treatment, it is necessary to control the content of triglycerides and cholesterol in the blood serum. Tamoxifen is ineffective in the treatment of patients who have metastases (especially to the liver).

Contraindications for use

Hypersensitivity, breastfeeding, pregnancy.

Application restrictions

History of pulmonary embolism and deep vein thrombosis in the treatment of indirect coumarin anticoagulants, leukopenia, thrombocytopenia, hyperlipidemia, hypercalcemia, visual impairment or cataract.

Use during pregnancy and lactation

Tamoxifen is contraindicated during pregnancy. At the time of treatment with tamoxifen, breastfeeding should be stopped.

Side effects of tamoxifen

Blood and circulatory system: thromboembolism, thrombophlebitis, thrombocytopenia, transient leukopenia;
sense organs and nervous system: headache, fatigue, dizziness, confusion, depression, blurred vision, retinopathy, cataracts, corneal changes;
digestive system: abdominal pain, nausea, loss of appetite, vomiting, constipation, increased levels of liver enzymes, severe violations of the functional state of the liver (hepatitis, cholestasis);
urinary system: vaginal discharge or bleeding, menstrual irregularity or amenorrhea in premenopausal women, itching in the genital area, development of reversible cystic ovarian tumors, fluid retention;
allergic reactions: rash on the code;
others: pain in the bones or / and in the area of ​​the lesion, alopecia, hypercalcemia, an increase in the size of the lesion and adjacent areas), paroxysmal sensation of heat, hyperthermia; with prolonged use - changes in the endometrium, which include intrauterine fibroids, polyps, hyperplasia and, in isolated cases, endometrial cancer.

Interaction of tamoxifen with other substances

With the joint use of tamoxifen with cytostatics, the possibility of thrombosis increases. Estrogens may reduce the therapeutic effects of tamoxifen when used together. Tamoxifen potentiates the effects of indirect anticoagulants. Tamoxifen may be used in combination with progestins.

P No. 015178/01-2003 dated 06/30/2003

Trade name of the drug: Tamoxifen-Ebewe

International non-proprietary name:

tamoxifen (tamoxifen)

Dosage form:

pills

COMPOUND.

1 tablet contains
Active substance: tamoxifen citrate 15.2 mg, 30.4 mg, 45.6 mg or 60.8 mg, which is equivalent to 10 mg, 20 mg, 30 mg or 40 mg tamoxifen, respectively.
Excipients: lactose, cellulose, starch, colloidal silicon dioxide, magnesium stearate.

DESCRIPTION

10 mg tablets
Round tablets, almost white, with a cross-shaped dividing groove on one side

Tablets 20 mg and 30 mg
Round tablets, almost white, with a dividing groove on one side

40 mg tablets
Tablets oblong, almost white, with a dividing groove on both sides

Pharmacotherapeutic group:

Anticancer agent, antiestrogen.

ATC code - L02BA01

PHARMACOLOGICAL PROPERTIES

Pharmacodynamics
Tamoxifen is a non-steroidal antiestrogenic agent that also has weak estrogenic properties. Its action is based on the ability to block estrogen receptors. Tamoxifen and some of its metabolites compete with estradiol for cytoplasmic estrogen receptor binding sites in breast, uterine, vaginal, anterior pituitary, and estrogen receptor-rich tumors. In contrast to the estrogen receptor complex, the tamoxifen receptor complex does not stimulate DNA synthesis in the nucleus, but inhibits cell division, which leads to regression of tumor cells and their death.

Pharmacokinetics
Tamoxifen is absorbed after oral administration. Peak serum concentrations are reached within 4 to 7 hours after a single dose. The equilibrium concentration of tamoxifen in serum is usually reached after 3-4 weeks of administration.

Metabolized in the liver with the formation of several metabolites. Elimination of tamoxifen from the body is biphasic with an initial half-life of 7 to 14 hours followed by a slow terminal half-life of 7 days. It is excreted mainly in the form of conjugates, mainly with feces, and only small amounts are excreted in the urine.

INDICATIONS FOR USE
Estrogen-dependent breast cancer in women (especially in menopause) and breast cancer in men.

The drug can be used for the treatment of ovarian cancer, endometrial cancer, kidney cancer, melanoma, soft tissue sarcomas in the presence of estrogen receptors in the tumor, as well as for the treatment of prostate cancer with resistance to other drugs.

CONTRAINDICATIONS

• Hypersensitivity to tamoxifen and / or any other ingredient of the drug.
• Pregnancy and lactation.

Carefully- renal failure, diabetes mellitus, eye diseases (including cataracts), deep vein thrombosis and thromboembolic disease (including history), hyperlipidemia, leukopenia, thrombocytopenia, hypercalcemia.

METHOD OF APPLICATION AND DOSES
The dosing regimen is usually set individually depending on the indications. The daily dose is 20-40 mg. As a standard dose, 20 mg of tamoxifen by mouth is recommended daily for a long time. With the appearance of signs of progression of the disease, the drug is canceled.

Tablets should be taken without chewing, with a small amount of liquid, in one dose in the morning or, dividing the required dose into two doses, in the morning and evening.

SIDE EFFECT
When treating with tamoxifen, the most common adverse reactions associated with its antiestrogenic effect, manifested in the form of paroxysmal sensations of heat (hot flashes), vaginal bleeding or discharge, itching in the genital area, alopecia, pain in the lesion, ossalgia, weight gain. The following adverse reactions were observed less frequently or rarely: fluid retention, anorexia, nausea, vomiting, constipation, fatigue, depression, confusion, headache, dizziness, drowsiness, fever, skin rash, blurred vision, including corneal changes, cataracts , retinopathy and retrobulbar neuritis.

At the beginning of treatment, a local exacerbation of the disease is possible - an increase in the size of soft tissue formations, sometimes accompanied by severe erythema of the affected areas and adjacent areas - which usually disappears within 2 weeks.

The likelihood of thrombophlebitis and thromboembolism may increase. Occasionally, transient leukopenia and thrombocytopenia may be observed, as well as an increase in liver enzymes, very rarely accompanied by more severe liver dysfunction, such as fatty liver, cholestasis and hepatitis.

In some patients with bone metastases, hypercalcemia was observed at the beginning of treatment. Tamoxifen causes amenorrhea or irregular menstruation in premenopausal women, as well as reversible development of cystic ovarian tumors.

With long-term treatment with tamoxifen, changes in the endometrium can be observed, including hyperplasia, polyps and, in rare cases, endometrial cancer, as well as the development of uterine fibroids.

OVERDOSE
No acute overdose of tamoxifen has been observed in humans. It should be expected that an overdose may cause an increase in the above adverse reactions. There are no specific antidotes, treatment should be symptomatic.

INTERACTION WITH OTHER DRUGS
With the simultaneous appointment of tamoxifen and cytostatics, the risk of thrombosis increases.

Antacids, H2-histamine receptor blockers and other drugs of similar action, by increasing the pH value in the stomach, can cause premature dissolution and loss of the protective effect of the enteric tablet. The interval between taking tamoxifen and these drugs should be 1-2 hours. There are reports of an increase in the anticoagulant effect of coumarin drugs (for example, warfarin) with tamoxifen.

Drugs that reduce calcium excretion (for example, thiazide diuretics) may increase the risk of hypercalcemia. The combined use of tamoxifen and tegafur may contribute to the development of active chronic hepatitis and cirrhosis of the liver.

The simultaneous use of tamoxifen with other hormonal drugs (especially estrogen-containing contraceptives) leads to a weakening of the specific action of both drugs.

SPECIAL INSTRUCTIONS
Women receiving tamoxifen should undergo regular gynecological examinations. With the appearance of bloody discharge from the vagina or vaginal bleeding, the drug should be discontinued. In patients with bone metastases, serum calcium levels should be determined periodically during the initial period of treatment. In case of severe disorders, tamoxifen should be temporarily discontinued.

If signs of thrombosis of the veins of the lower extremities appear (pain in the legs or their swelling), pulmonary embolism (shortness of breath), the drug should be discontinued. Tamoxifen can cause ovulation, which increases the risk of pregnancy, and therefore women who are sexually active during (and for about 3 months after) treatment with tamoxifen, the use of a mechanical or non-hormonal contraceptive is recommended.

During the period of therapy, it is necessary to periodically monitor blood coagulation indicators, calcium content in the blood, blood picture (leukocytes, platelets), liver function indicators, blood pressure, and conduct an examination with an ophthalmologist.

In patients with hyperlipidemia during treatment, it is necessary to control the concentration of cholesterol and TG in the blood serum. During the period of treatment, it is necessary to refrain from engaging in potentially hazardous activities that require increased concentration of attention and speed of psychomotor reactions.

RELEASE FORM
Tablets of 10 mg, 20 mg, 30 mg and 40 mg.
10 tablets in a blister pack made of aluminum foil; 3 packs in a cardboard box with attached instructions for use.

STORAGE CONDITIONS
List B. In a dry, dark place at a temperature not exceeding 25 ° C

TERMS AND CONDITIONS OF DISCOUNT FROM PHARMACIES
By prescription.

MANUFACTURER
EBEWE Pharma Ges.m.b.H.Nfg.KG A-4866 Unterach, Austria, Europe.

Claims of consumers should be sent to ZAO Sandoz: 123317, Moscow, Presnenskaya nab., d.; 8, p. 1.

Tamoxifen: instructions for use and reviews

Latin name: Tamoxifenum

ATX code: L02BA01

Active substance: Tamoxifen citrate (Tamoxifen citrate)

Manufacturer: Shreya Life Sciences Pvt.Ltd (India), Severnaya Zvezda CJSC, Obolenskoye Pharmaceutical Enterprise CJSC, OZON Pharmaceutical Company (Russia), Orion Corporation (Finland)

Description and photo update: 12.08.2019

Tamoxifen is a non-steroidal antiestrogen drug with antitumor activity.

Release form and composition

Dosage form of release of Tamoxifen - tablets: from white to white with a creamy or grayish tint, flat-cylindrical; 10 mg each - with a chamfer; 20 mg each - with a notch and a chamfer (30, 50, 100 pieces in bottles, 1 bottle in a carton box; 10 or 30 pieces in blister packs, 1-6 or 10 packs in a carton box; 10, 20, 30, 40, 50 or 100 pieces in plastic containers, 1 container in a carton box).

Composition of 1 tablet:

• active substance: tamoxifen - 10 or 20 mg (tamoxifen citrate - 15.2 mg or 30.4 mg);
• auxiliary components (10/20 mg, respectively): magnesium stearate - 1.8 / 3.6 mg; lactose monohydrate - 117.2 / 234.4 mg; povidone - 6.1 / 12.2 mg; potato starch - 39.7 / 79.4 mg.

Pharmacological properties

Pharmacodynamics

Tamoxifen is a non-steroidal antiestrogen drug that also has weak estrogenic activity. The mechanism of its action is due to the ability to block estrogen receptors. Metabolites of the drug and tamoxifen itself compete with estradiol by binding to cytoplasmic estrogen receptors located in the tissues of the anterior pituitary gland, uterus, vagina, breast, and also in tumor tissues. The tamoxifen receptor complex, unlike the estrogen receptor complex, does not stimulate DNA formation in the nucleus. It inhibits cell division, causing tumor cells to die.

Pharmacokinetics

Tamoxifen is well absorbed when taken orally. Its maximum serum concentration is reached within 4-7 hours after taking a single dose. Steady-state drug concentrations are observed in serum after approximately 3-4 weeks of treatment. Tamoxifen is 99% bound to plasma proteins.

Metabolism of the drug is carried out in the liver with the participation of the CYP2C9 isoenzyme. As a result, several metabolites are formed.

Tamoxifen is eliminated in two phases: the initial half-life is 7-14 hours, the terminal half-life is 7 days. The drug is excreted mainly in the form of metabolites and mainly through the intestines. Only a small part of tamoxifen is excreted by the kidneys.

Indications for use

• early breast cancer with estrogen-positive receptors (adjuvant therapy);
• locally advanced or metastatic breast cancer with estrogen-positive receptors (treatment);
• breast cancer, including in male patients after castration.

In the presence of overexpression of estrogen receptors, Tamoxifen can also be used in the treatment of other solid tumors that are resistant to standard therapies.

Contraindications

Absolute:

• age up to 18 years (for this category of patients, the safety profile has not been studied);
• pregnancy and lactation;
• hypersensitivity to the components of the drug.

Relative (Tamoxifen is prescribed with caution in the presence of the following diseases / conditions):

• eye diseases, including cataracts;
• hyperlipidemia;
• hypercalcemia;
• thrombocytopenia;
• severe thrombophlebitis;
• liver disease;
• thromboembolic disease, including the presence of anamnestic data;
• leukopenia;
• hereditary lactose intolerance, lactase deficiency or malabsorption of galactose / glucose (Tamoxifen contains lactose).

Instructions for use Tamoxifen: method and dosage

Tamoxifen is taken orally with a small amount of liquid. Tablets should not be chewed.

The daily dose is taken 1 time per day (in the morning) or divided into 2 doses (in the morning and evening).

Usually, the doctor determines the dosage regimen individually.

The daily dose may vary from 20 to 40 mg.

In cases of symptoms of disease progression, Tamoxifen is canceled.

Side effects

The most common side effects of Tamoxifen are associated with its antiestrogenic effect, they manifest as paroxysmal sensations of heat (hot flashes), vaginal bleeding or discharge, itching in the genital area, alopecia, pain in the lesion, ossalgia, weight gain.

The development of the following disorders is less common: allergic reactions (including angioedema), fever, anorexia, fluid retention, nausea, constipation, vomiting, confusion, depression, fatigue, headache, drowsiness, dizziness, skin rash (including isolated cases erythema multiforme, Stevens-Johnson syndrome and bullous pemphigoid), visual disturbances (including retinopathy, cataracts, corneal changes), retrobulbar neuritis, decreased libido in men, impotence.

In very rare cases, the development of interstitial pneumonitis has been noted during the use of Tamoxifen.

At the beginning of the course, there may be a local exacerbation of the disease (in the form of an increase in the size of soft tissue formations), in some cases it is accompanied by severe erythema of the affected areas and adjacent areas. As a rule, these disorders are transient and disappear within 14 days.

Other possible disorders: often - leg cramps; infrequently - transient thrombocytopenia / leukopenia, increased activity of liver enzymes (in very rare cases, accompanied by more severe functional disorders of the liver - fatty liver, hepatitis, cholestasis); rarely - an increase in the concentration of serum triglycerides (sometimes occurs in combination with pancreatitis).

In some patients with bone metastases at the beginning of the course, the development of hypercalcemia was observed. During the use of Tamoxifen, the likelihood of thromboembolism and thrombophlebitis may increase.

Possible side effects of Tamoxifen in women: amenorrhea or irregularity of the onset of menstruation (in the premenopausal period), reversible cystic ovarian tumors; with prolonged use of the drug - changes in the endometrium, including uterine myoma, polyps, hyperplasia, in isolated cases - uterine sarcoma and endometrial cancer.

Overdose

Cases of acute overdose have not been registered. When taking ultra-high doses of the drug, symptoms of neurotoxicity may develop: dizziness, hyperreflexia, tremor, unsteady gait.

There is no specific antidote for Tamoxifen. In case of overdose, symptomatic treatment is prescribed.

special instructions

Women during the period of taking Tamoxifen are shown to conduct regular (1 time in 3 months) gynecological examinations. In cases of bleeding from the vagina or vaginal bleeding, therapy is canceled.

Tamoxifen may induce ovulation, which increases the chance of pregnancy. During the period of use of the drug and for 3 months after the end of the course, women of reproductive age are recommended to use reliable non-hormonal methods of contraception.

In the presence of bone metastases, the serum calcium concentration in the blood should be determined periodically during the initial period of therapy. With severe disorders (hypercalcemia), Tamoxifen is temporarily stopped.

Against the background of hyperlipidemia, it is necessary to control the serum concentration of cholesterol and triglycerides in the blood.

In cases of signs of thrombosis of the veins of the lower extremities (in the form of pain in the legs or their swelling), pulmonary embolism (in the form of shortness of breath), therapy is canceled.

During treatment, the following indicators should be periodically monitored: blood coagulation, liver function, calcium in the blood, blood picture (leukocytes, platelets). It is also necessary to control blood pressure and conduct an examination by an ophthalmologist every 3 months.

Use during pregnancy and lactation

According to the instructions, Tamoxifen should not be used during pregnancy. If there is a need to take the drug during breastfeeding, breastfeeding should be discontinued.

In the conducted experimental studies, it was found that tamoxifen has a teratogenic effect on the fetus.

Application in childhood

The drug is prohibited for use in children and adolescents under 18 years of age, since there are no data on the safety and efficacy of Tamoxifen in children.

drug interaction

With the combined use of Tamoxifen with certain drugs / substances, the following effects may develop:

• indirect anticoagulants - coumarin derivatives (for example, warfarin): increased anticoagulant effect;
• cytostatics: increased likelihood of thrombosis;
• tegafur: increased likelihood of developing cirrhosis of the liver and active chronic hepatitis;
• drugs that lower the excretion of calcium (for example, thiazide diuretics): an increase in the likelihood of hypercalcemia;
• bromocriptine: an increase in the plasma concentration of tamoxifen and N-desmethyltamoxifen in the blood;
• other hormonal drugs (especially estrogen-containing contraceptives): weakening the effect of both drugs.

Analogues

Analogues of Tamoxifen are: Tamoxifen Geksal, Tamoxifen-Ferein, Vero-Tamoxifen, Tamoxifen Lahema, Tamoxifen-Ebewe, Fareston, Faslodex.

Terms and conditions of storage

To store in the place protected from light at a temperature up to 25 °C. Keep away from children.

Shelf life - 2 years.