Farmgruppa: antitumor agent - antiestrogen.
Farmdeystvie: Antitumor antiestrogennoe means. Competitive ingibiruet estrogen receptors in target organs and tumors originating from these bodies. As a result of a complex of (drug-receptor-cofactor transfer), which after translocation in the cell nucleus prevents hypertrophy of the cells that depend on estrogen regulation.
Has antigonadotropnym properties, suppresses the synthesis of Pg in the tumor tissue. Delays the progression of the tumor process, stimulated by estrogen.
The ability to block estrogens may persist for several weeks after a single dose.
In addition, tamoxifen may cause ovulation in women in its absence, by stimulating the release of hypothalamic FRG, stimulating the release of gonadotropic hormones of the pituitary gland. In men with oligospermia increases the concentration of LH and FSH, testosterone and estrogen in the blood serum.
Tamoxifen and some of its metabolites (N-dezmetiltamoksifen, 4 gidroksitamoksifen) are strong oxidase inhibitor mixed functions of the system zitohroma P450 liver, but the clinical significance of these effects is not defined.
Pharmacokinetics: Absorption is high, TCmax - 4-7 hours after the intake of the achievements of the Css - 4 weeks. Connection with the plasma protein - 99%.
Metabolised by demetilirovania gidrauxilirovania and in the liver. Participates in the metabolism of CYP2C9 isoenzyme.
Elimination is biphasic with the initial T1 / 2 - 7-14 hours and with the subsequent slow end T1 / 2 - 7 days. It is excreted mainly through the intestine, mainly in the form of metabolites; small number of kidneys.
Indications: breast Cancer (especially in menopause);
breast cancer (including the men after castration);
carcinoma in situ duct of the breast;
endometrial cancer;
estrogenchuvstvitelnye tumors;
adjuvant therapy for breast cancer.
The category of a fetus: the CATEGORY of ACTION ON the FETUS. D (There is evidence of a risk of adverse effects of DRUGS on the fetus man obtained in research or in practice, however, the potential benefits associated with the use of DRUGS in pregnant women, can justify its use, despite the potential risk.)
Contraindications: Hypersensitivity, severe thrombocytopenia, lakopenia, gipercalziemia, thrombosis of deep veins, tromboembolia pulmonary artery in disorder on the background of the treatment of indirect antikoagulyantami st. series, pregnancy, lactation period.
With caution. Diseases of the eye (including cataracts), hyperlipidemia, expressed thrombophlebitis, thromboembolic disease (including in history), diseases of the liver.
Dosage: Usually is determined individually depending on the testimony.
Inside, the cancer of the breast on 20-40 mg 1-2 times a day (morning and evening), endometrial - 20-30 mg 1-2 times a day. Treatment of a long-term (up to the appearance of signs of disease progression), because the effect is preserved only on the background of permanent use; if necessary, use in combination with radiation and cytostatic therapy.
The maximum daily dose of 40 mg.
Tablets should be taken not liquid, squeezed small amounts of liquid, in one dose in the morning or the sharing of the necessary dose in 2 admission, in the morning and in the evening.
Side effects: Very often - more than 10%, often - 1-10%, rarely - 0.1-1%, rarely - 0.01-0.1%; very rare - less than 0.01%, including individual cases.
From the body of the blood: rarely - tranzitornaya lakopenia, thrombocytopenia; very rarely - neutropenia.
Allergic reactions: rarely hypersensitivity, angioneuroticeski swelling.
From the nervous system: rarely, dizziness, headache; rarely is a violation of taste, leg cramps, depression, decreased libido in men, drowsiness, sputannosti consciousness.
From the sensory organs: rarely - reduced visual acuity, corneal opacity, cataract, retinopathy, postbulbar neuritis.
By the CCC: very often, "tides" heat-to-face; infrequent thrombosis (risk increases with concomitant cytostatic therapy).
From the respiratory system: very rare: acute pulmonary embolism.
From the digestive system: very often, nausea, vomiting; rarely - constipation, diarrhea, pancreatitis, fatty degeneration of the liver, holetaz, hepatitis, severe violation of the functions of the liver.
From the skin: rarely skin rashes, alopecia; rarely - increased hair growth, mnogoformnaya erythema, syndrome Stevens-Johnson; the frequency is unknown and dryness of the skin.
On the part of the reproductive system: very often, abnormal vaginal bleeding, a violation of menstruation, abnormal vaginal discharge; infrequent - ovarian cyst (at reception in premenopausal); rarely - itching of the vulva, impotence in men, proliferative changes in the endometrium (hyperplasia of the endometrium, endometriosis).
Laboratory data: rarely - hyperlipidemia, increased activity of hepatic enzymes; very rarely - hypertriglyceridemia, hypercalcemia in patients with metastases in the bones.
Other: very often, the delay fluid; infrequent - carcinogenic effect, fatigue; rarely - bullous pemphigoid, anorexia; the frequency is unknown and bone pain, pain in the lesions, increased body temperature, increase the size of the soft tissue formations, sometimes accompanied by a marked erythemas the affected areas and adjacent areas (usually passes within two weeks), the increase in body mass, myasthenia gravis, increased fatigue.
Overdose: Symptoms: tremor, hyperreflexia, staggering gait, dizziness.
Treatment: symptomatic, the lifting of the preparation.
Interaction: Increases the effect of indirect anticoagulants (to be closely monitored for dose adjustment anticoagulants).
Reduces the serum concentration of letrozole by 37%.
Cytostatics increase the risk tromboobrazovania.
The combined use of tamoxifen and teghafur may cause chronic active hepatitis and cirrhosis of the liver.
The simultaneous use of tamoxifen with estrogen PP (including estrogen contraceptives) leads to a weakening of the specific actions of both DRUGS.
DRUGS that reduce the excretion of Ca2 + (for example, tiazidnye dioretiki increase the risk of developing gipercalziemii.
Bromocriptine increases serum concentrations of tamoxifen.
Antacids, H2-blockers gistaminovykh receptors, etc. DRUGS that reduce the acidity of gastric juice, can cause premature dissolution and the loss of the protective effect of enteric-soluble coating tablets. The interval between the reception of tamoxifen and these DRUGS should be 1-2 hours.
Special instructions: Before the beginning of the treatment of women must go through a thorough gynecological (the exclusion of pregnancy) and a physical examination.
Clomid causes ovulation, which increases the risk of pregnancy, and women of childbearing age should use reliable methods of contraception (non-steroidal) in the period of treatment and within 3 months after the end of treatment.
In the period of treatment should be periodically monitored indicators of blood coagulation, the concentration of Ca2 + in the blood, a picture of the blood (leukocytes, platelets), the liver, HELL, to conduct an examination by an ophthalmologist every three months, gynaecological examination (at the blood-tinged discharge from the vagina or vaginal bleeding of the drug should be discontinued).
In patients with metastases in the bones periodically during the initial period of treatment should determine the concentration of Ca2 + in the blood serum (in the case of expressed hypercalcaemia reception of tamoxifen should temporarily stop). Is not effective in the treatment of patients with metastasis (especially the liver).
When the signs of venous thrombosis of the lower extremities (pain in the legs or swelling), thromboembolism branches of the pulmonary artery (shortness of breath) the drug should be discontinued.
In patients with hyperlipidemy in the course of treatment necessary to control the concentration of cholesterol and TG in the blood serum.
In the period of treatment should be careful when driving vehicles and occupation of other potentially hazardous activities that require high concentration and psychomotor speed reactions.