Absorption and distribution After oral administration, tamoxifen is well absorbed. The cmax in the serum is reached within 4 to 7 hours after taking a single dose.The equilibrium concentration of tamoxifen in the blood serum is usually reached after 3-4 weeks of administration. The binding to plasma proteins is 99%.Metabolism and excretionmetabolized in the liver to form several metabolites.The elimination of tamoxifen from the body has a two-phase character with an initial T1 / 2 from 7 to 14 hours and followed by a slow terminal T1 / 2 for 7 days. It is excreted mainly in the form of conjugates, mainly with feces, and only small amounts are excreted in the urine.
- 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.
- pregnancy; - lactation (breastfeeding);- hypersensitivity to tamoxifen and / or any other ingredient of the drug.With caution: renal failure, diabetes mellitus, eye diseases (including cataracts), deep vein thrombosis and thromboembolic disease (including in the anamnesis), hyperlipidemia, leukopenia, thrombocytopenia, hypercalcemia, concomitant therapy with indirect anticoagulants.
- Do not exceed the recommended daily dose.
- Use during pregnancy and lactation
- The use of the drug during pregnancy is contraindicated.There is insufficient data on whether tamoxifen penetrates into breast milk, so during lactation, the drug should not be used or it is necessary to decide whether to stop breastfeeding.
Method of administration and dosage
The dosage regimen is usually set individually depending on the indications.The daily dose is 20-40 mg. As a standard dose, it is recommended to take 20 mg of tamoxifen orally daily for a long time. If there are signs of progression of the disease, the drug is canceled.Tablets should be taken without chewing, washed down with a small amount of liquid, in 1 dose in the morning, or by dividing the required dose into 2 doses in the morning and evening.
Acute tamoxifen overdose in humans was not observed. It should be expected that an overdose may cause an increase in the above-described adverse reactions.There are no specific antidotes, and treatment should be symptomatic.