Index of drugs

Supplementary treatment after primary breast cancer therapy. Treatment of advanced metastatic breast cancer.

1 tabl powl. contains 20 mg of Tamoxifen (and 144.4 mg of lactose).

A synthetic non-steroidal compound with strong anti-estrogenic activity by competitive blocking of estrogen receptors in target tissues. It has its own small, intrinsic estrogenic activity. Specific target receptors for Tamoxifen, different from estrogen receptors that may exist without these receptors, have also been identified in the target cells. They are heat-stable proteins. This phenomenon is probably responsible for the effects of the drug even in the receptor - negative cells. Tamoxifen inhibits the mitosis of cells with estradiol receptors (receptor positive: ER (+)). The sensitivity of breast cancer to the drug is strictly dependent on the number of ER in the tissue, and increases when the tumor cells also contain receptors for progesterone. There is also a direct anticancer effect and the possibility of inhibiting tumor growth by affecting the function of the hypothalamus - pituitary - ovary system. Recently, the fact of blocking the synthesis of cancer cell growth factor by antiestrogens has also been raised. Tamoxifen stops tumor growth in the G1 phase of the cell cycle. After oral administration, it quickly absorbs from the gastrointestinal tract, reaching a maximum concentration in the blood after 4-7 h. The constant, therapeutic concentration of the drug in the blood can be achieved after a saturation period of about 4 weeks at a daily dose of 40 mg of the drug. About 98% is associated with albumin. It undergoes hydroxylation, demethylation and conjugation in the liver. Drug metabolites are less active. They are excreted with faeces. T_0,5 is 7 days for the basic substance and 14 days for the main metabolite, which is desmethylotamoxifen. The best treatment is cancerous changes in soft tissues, slightly worse - in the bones, and less well - in the parenchymal organs. In metastatic breast cancer, total or partial regression occurs in about 50-60% of cases, if there are estrogen receptors in cancer tissue and only in about 10% of cases when there are no such receptors.

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. Pre-menopausal women should be carefully examined before starting treatment to rule out pregnancy. Due to the increased risk of cancer associated with tamoxifen treatment, every patient should be immediately identified for any bleeding from the genital tract or irregular bleeding, vaginal discharge, feeling of increased pressure in the pelvis or pelvic pain. During treatment with tamoxifen, patients with a preserved uterus should undergo gynecological examination each year for changes in the endometrium. 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. At the beginning of treatment with tamoxifen, ophthalmologic examination should be performed. If vision disturbances occur during tamoxifen therapy, an ophthalmologic examination is required as some lesions detected at an early stage disappear after discontinuation of treatment. Patients treated with tamoxifen have a 2-3 times increased risk of venous thrombosis. This risk increases in the case of coexistence of obesity, old age and concurrent chemotherapy. In patients with breast cancer and co-existing risk factors for venous thrombosis, long-term anticoagulant therapy should be considered. Tamoxifen treatment should be discontinued only if the risk of venous thrombosis due to tamoxifen therapy outweighs the benefits of abrupt cessation of treatment.Patients should be advised about the possibility of venous thrombosis and the need to seek medical advice as soon as possible if any symptoms of thrombosis are observed - in such cases, tamoxifen should be discontinued and appropriate anticoagulant therapy instituted. During treatment with tamoxifen, the morphological image of the blood including the platelet count should be monitored regularly), liver function, serum Calcium and triglyceride levels. 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 in 28 girls aged 2 to 10 years with McCune-Albright syndrome, who received 20 mg 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 of the year research. No causal relationship has 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 galactose intolerance, Lapp lactase deficiency or glucose-galactose malabsorption.

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.

Very often: hot flushes, discharge from the genital tract, premenopausal patients - disturbance of the cycle until the menstrual cycle is stopped, fluid retention, nausea, skin rash (including rare erythema multiforme, Stevens-Johnson syndrome, pemphigus). Common: in the initial period of treatment of bone pain and pain around the affected tissue, increased triglycerides in the blood, transient anemia, hypercalcemia (in patients with bone metastases, especially at the beginning of treatment), dizziness, headache, visual impairment (only partially reversible, often caused by cataracts, corneal opacity and / or retinopathy, cataract risk increases with the use of tamoxifen), cerebral ischemic events, leg cramps, thromboembolic events, including deep veins thrombosis, pulmonary embolism ( especially in combination therapy with chemotherapeutics), vomiting, diarrhea, constipation, changes in liver enzymes, fatty liver, alopecia, hypersensitivity reactions (including rare angioneurotic edema), muscle pain, vulvar itching, uterine myomas, proliferative endometrial changes (neoplasia, hyperplasia endometrial polyps, r satisfactory endometriosis). Uncommon: leukopenia and transient thrombocytopenia, stroke, interstitial pneumonitis, cirrhosis, endometrial cancer. Rare: agranulocytosis, neutropenia, ocular neuropathy, ocular inflammation (in rare cases with loss of vision), cutaneous vasculitis, enlargement of the ovarian cysts, uterine sarcoma (mostly mixed malignant tumors derived from Muller's ducts), polyps of the mucous womb. Very rare: severe neutropenia and pancytopenia, severe hypertriglyceridaemia (sometimes with pancreatitis), cholestasis, hepatitis, jaundice, necrosis / liver cell injury, hepatic failure (some cases fatal), cutaneous form of Lupus Erythematosus, late dermatopathy. The risk of endometrial cancer increases 2-4 times as the duration of treatment with tamoxifen is increased, compared with women who are not treated with this drug.

Orally. Adults: The usual dose is 20-40 mg / day. A dose of 20 mg is usually sufficient. In supplementary treatment of positive hormone receptor-positive breast cancer, at least 5-year treatment is recommended. The optimal duration of treatment has not yet been established.Special groups of patients.
The use is not recommended in children, as the safety and efficacy of tamoxifen have not been established.Way of giving. The drug should be taken during meals, swallowing whole tablets and with liquid.