Index of drugs

Treatment of breast cancer.

1 tabl contains 10 mg or 20 mg Tamoxifen (and 69.9 mg and 139.2 mg lactose, respectively).

A powerful, non-steroidal estrogen antagonist. It exhibits anti-estrogen activity by binding to the steroid blocking domain in the estrogen receptor and inhibiting the action of estradiol. After oral administration, tamoxifen is rapidly absorbed into the blood and reaches C_maxafter 4-7 h. The steady state concentration is reached after about 4 weeks of treatment (dose of 40 mg per day). Tamoxifen is almost 100% bound to plasma proteins. It is metabolized in the process of hydroxylation, demethylation and coupling. Some of the metabolites have a clinical effect similar to tamoxifen. It is excreted primarily with faeces. T_0,5 tamoxifen is about 7 days and his main metabolite, N-demethylamamoxifene, 14 days.

Hypersensitivity to the active substance or to any of the excipients. Severe thrombocytopenia, leukopenia or hypercalcaemia. Pregnancy.

During treatment, a certain percentage of premenopausal women develop suppression of menstruation. Exercise caution and carefully monitor the condition of patients with liver and kidney disease, diabetes mellitus, history of thromboembolism or visual disturbances. All patients should be assessed for the risks and benefits of tamoxifen therapy prior to its use. Before starting treatment, and then at intervals of at least 6 months, an internal examination should be performed. Patients should also be subjected to a gynecological examination and thoroughly examine any abnormal symptoms, ie uterine bleeding with unexplained etiology, irregular menstruation, discharge and pelvic pain or pressure. Women should be carefully monitored for any proliferation of the endometrium. In the event of atypical hyperplasia, tamoxifen should be discontinued, appropriate treatment is instituted, and hysterectomy should be considered before restarting the treatment. During clinical trials, primary tumors other than endometrial tumors or second breast cancers have been observed. No causal relationship was established with the use of tamoxifen or the clinical significance of this observation. It is recommended to perform ophthalmologic examinations before and at the beginning of treatment, as well as in the case of vision disorders (visual impairment). Research may reveal early corneal or retinal damage that may resolve after discontinuation of treatment. Patients with pre-existing liver disease require careful monitoring of their liver function. Periodically, blood (especially platelet counts), liver and kidney function should be monitored, and blood and Calcium levels should be measured. In order to detect metastases early, further periodic check-ups (X-ray examination of lungs and bones, liver ultrasound) are recommended. Patients being treated with tamoxifen increase the risk of venous thromboembolism. In patients with breast cancer a detailed history should be conducted, including a family history of venous thromboembolism. In patients with factors that promote thromboembolic events, detailed studies should be performed to confirm the risk of thromboembolism. The decision to use tamoxifen should be made on the basis of risk assessment of thromboembolic syndrome and the benefits of treatment. In some patients, the simultaneous use of tamoxifen and anticoagulant prophylaxis may be warranted. In patients with breast cancer, the risk of thromboembolic syndrome is also greater when chemotherapy is co-administered. If the patient develops symptoms of thromboembolism, treatment with tamoxifen should be stopped immediately and adequate anticoagulation should be initiated. The decision to re-apply tamoxifen should be made taking into account the risks associated with both its use and the lack of tamoxifen treatment.Patients should be advised to contact their physician immediately if signs of thromboembolic syndrome are observed. The use of tamoxifen in immobilized patients after surgery can be discontinued only if the risk of thromboembolic syndrome significantly exceeds the risks associated with discontinuation of treatment. Appropriate anticoagulant prophylaxis should be used in all patients. During hospitalization, anticoagulant stockings should be used, the patient should be started as early as possible and anticoagulant therapy. There have been reports of decreased concentrations of endoxifen (one of the most important active metabolites of tamoxifen) in the plasma of metabolically metabolised patients with the CYP2D6 isoenzyme. The concomitant use of drugs that inhibit CYP2D6 activity may result in a reduction in endoxifen levels, therefore, strong CYP2D6 inhibitors should be avoided during treatment with tamoxifen. It is recommended that blood counts (including platelet counts), liver function and serum calcium levels are regularly monitored. In cases of severe thrombocytopenia, leukopenia or hypercalcaemia, an individual assessment of the benefit / risk ratio and particularly careful monitoring of the patient's condition are necessary. In an uncontrolled study involving 28 girls aged 2 to 10 years with McCune-Albright syndrome) who received 20 mg of tamoxifen once daily for up to 12 months, the mean uterine volume was increased after 6 months of treatment and doubling its volume at the end annual survey. A causal relationship has not been established, although the observation corresponds to the pharmacodynamic properties of tamoxifen. Due to the lactose content, the preparation should not be used in patients with hereditary galactose intolerance, lactase deficiency (Lapp type) or malabsorption of glucose-galactose.

The preparation must not be used during pregnancy. There are a small number of reports of spontaneous abortions, congenital malformations and fetal death, although the causal relationship has not been established. Before starting treatment, the patient should be excluded and tamoxifen treated with effective non-hormonal methods of contraception during treatment and for at least 2 months after its completion. Patients should be informed about the potential harm to the fetus to be during tamoxifen therapy during pregnancy or within 2 months of the end of treatment. Tamoxifen 20 mg twice daily inhibits lactation in humans. Milk production does not resume even after discontinuation of treatment, therefore breastfeeding is not possible during tamoxifen therapy. Before starting treatment with the product, stop breast-feeding or do not take tamoxifen before stopping breastfeeding.

Very common: fluid retention, nausea, skin rash (including rare erythema multiforme, Stevens-Johnson syndrome or pemphigus), unusual bleeding from the genital tract, menstrual disorders up to complete suppression of menses in pre-menopausal women, vaginal discharge, hot flushes. Common: transient anemia, hypercalcaemia in patients with bone metastases (especially at the beginning of treatment), increased serum triglycerides, dizziness, headache, visual disturbances (only partially reversible, due to cataract, corneal opacity and / or retinopathy, cataract risk increases with the duration of treatment with tamoxifen), cerebral ischemic events, leg cramps, thromboembolic events (including deep vein thrombosis and pulmonary embolism, especially in combination therapy with chemotherapeutics), vomiting, constipation, diarrhea, changes in enzyme activity liver, fatty liver, alopecia, hypersensitivity reactions (including rarely angioneurotic edema), muscle pain, vulvar itching, uterine fibroids, proliferative endometrial changes (neoplasia, hyperplasia and endometrial polyps, rare endometriosis), in the initial period of bone pain therapy and pain in area of ​​tissue ob suffering from the disease. Uncommon: redness of the tumor, leukopenia (sometimes with anemia and / or thrombocytopenia), transient thrombocytopenia, stroke, interstitial pneumonitis, liver cirrhosis, fatigue, dissociation. Rare: agranulocytosis, neutropenia, hypertriglyceridemia (sometimes with pancreatitis), depression, loss of libido in men, taste disorders, leg tremors, ocular neuropathy, optic nerve inflammation (in rare cases with loss of vision), cutaneous vasculitis, intense hair growth, enlargement of ovarian cysts in premenopausal women, uterine sarcoma (mostly mixed malignant tumors derived from Muller's ducts), endometrial polyps, impotence in men, changes in serum lipid profile.Very rare: severe neutropenia and pancytopenia, cholestasis, hepatitis, jaundice, hepatic cell necrosis, liver cell damage, liver failure (some cases of more severe hepatic impairment), cutaneous form of Lupus Erythematosus, late dermatozoon porphyria. It is possible to intensify existing skin lesions or the appearance of new ones. The risk of developing cancer of the endometrium increases with the duration of treatment; it was found that it was 2-3 times higher in patients treated with tamoxifen than in non-treated women. Most side effects are transient and can often be prevented by reducing the dose.

Orally. Adults: the recommended dose is 20 mg per day. In patients with advanced disease, doses of 30 or 40 mg were used. The maximum daily dose is 40 mg. Response to treatment is usually observed within 4-10 weeks of treatment, in patients with bone metastases, it may occur only after a few months.Special groups of patients. It is not necessary to adjust the dosage in elderly patients or in patients with impaired renal function. The preparation is not recommended for children, as the safety and efficacy of tamoxifen in this age group have not been established. Way of giving. The tablets should be taken with food, swallowed whole with a sufficient amount of liquid. If it is necessary to take more than one tablet, you can take it once or twice a day. The treatment time is determined individually for each patient.