Index of drugs

Supplementary treatment in postmenopausal women with early stage of breast cancer with hormone receptors. Prolonged follow-up treatment in postmenopausal women with hormone-dependent breast cancer at an early stage following standard follow-up treatment with Tamoxifen for 5 years. First-line treatment of advanced hormone-dependent breast cancer in postmenopausal women. Treatment of advanced breast cancer in postmenopausal women who have appeared physiologically or have been artificially induced who have had a recurrence of cancer or progression of a cancerous process that had previously been treated with anti-estrogen drugs. No drug efficacy was found in patients with breast cancer without hormone receptors.

1 tabl powl. contains: 2.5 mg letrozole. The preparation contains lactose.

An anticancer drug - a non-steroidal aromatase inhibitor - an enzyme that converts adrenal androgens to oestrone and estradiol. Selective inhibition of aromatase causes the inhibition of estrogen biosynthesis in peripheral tissues and in tumor tissue itself. Letrozole inactivates aromatase by competitive binding to the aromatase-cytochrome P-450 complex, thereby inhibiting the biosynthesis of estrogens in all tissues in which the aromatase is located. In postmenopausal women with advanced breast cancer treated with a daily dose of 0.1-5 mg, letrozole reduces the estradiol, oestrone and estrone sulfate concentrations in the blood by 75-95% in all treated patients in relation to the baseline values. Letrozole is highly specific in inhibiting aromatase activity, therefore, there is no need for adjuvant treatment with glucocorticosteroids or mineralocorticoids. After oral administration, letrozole is rapidly and completely absorbed from the gastrointestinal tract (bioavailability is 99.9%). The presence of food slightly reduces the rate of absorption of the drug, but has no effect on bioavailability. The drug is bound to plasma proteins in about 60%. The concentration of letrozole in erythrocytes is approximately 80% of the plasma concentration. It is quickly distributed to tissues. The main route of letrozole metabolism is the reduction to the pharmacologically inactive metabolite - carbinol, which is carried out with the participation of the 3A4 and 2A6 cytochrome P450 isoenzymes. It is excreted mainly in the urine (approximately 90%), where 6% of the drug was administered unchanged and 75% as a metabolite. The remainder is excreted in the faeces (approximately 3.8%). T_0,5 is about 2 days.

Hypersensitivity to letrozole or other ingredients of the preparation. Women before menopause. Pregnancy and breastfeeding.

There is insufficient data on patients with renal insufficiency with a creatinine clearance <30 ml / min or severe hepatic impairment. In patients with severe hepatic impairment, the product can only be used after careful consideration of whether the expected benefits outweigh the risks. Patients with a history of osteoporosis and / or fracture or who are at higher risk for osteoporosis should have a bone densitometry examination prior to initiating adjuvant or prolonged adjuvant treatment and should be monitored for the development of osteoporosis during and after treatment . If there are indications, treatment or prevention of osteoporosis should be initiated and its efficacy monitored regularly. Due to the lactose content, the preparation should not be used in patients with rare hereditary galactose intolerance, Lapp lactase deficiency or malabsorption of glucose-galactose.

In women of perimenopausal or childbearing age, a pregnancy test should be performed and appropriate contraception should be used prior to commencement of treatment until the postmenopausal state is confirmed. The preparation is contraindicated in pregnancy and breast-feeding.

Very common: increased sweating, joint pain, hot flushes, fatigue, asthenia.Common: anorexia, increased appetite, hypercholesterolemia, depression, headache, dizziness, nausea, vomiting, indigestion, constipation, diarrhea, alopecia, rash (including erythematous rash, maculopapular mumps resembling psoriasis, blistering rash), muscle aches, pains bones, osteoporosis, bone fractures, malaise, peripheral edema, weight gain. Uncommon: urinary tract infections, cancer pain (not applicable to adjuvant treatment and prolonged adjuvant treatment), leukopenia, generalized edema, anxiety, nervousness, irritability, drowsiness, insomnia, memory disorders, sensory disturbances (including paresthesias and asthenia sensation), taste, cerebral stroke, cataracts, eye irritation, blurred vision, palpitations, tachycardia, thrombophlebitis (including superficial and deep phlebitis), hypertension, ischemic heart disease, shortness of breath, cough, abdominal pain, stomatitis, dry membrane mucous oral cavity, increased liver enzymes, itching of the skin, dry skin, urticaria, arthritis, frequent urination, bleeding from the genital tract, profuse vaginal discharge, vaginal dryness, chest pain, fever, dry mucous membranes, increased thirst, weight loss. Rare: pulmonary embolism, arterial thrombosis, ischemic stroke.

Orally. Adult and elderly patients: 2.5 mg once a day. In adjuvant therapy, treatment should be continued for 5 years or until tumor disease returns. In complementary therapy, clinical experience covers a period of 2 years (the average duration of treatment was 25 months). In long-term adjuvant treatment, clinical experience covers a period of 3 years (mean duration of treatment). In patients with advanced or metastatic breast cancer, treatment should be continued until evidence shows that the cancer process has progressed.
No dosage adjustment is necessary for patients with renal impairment with creatinine clearance> 30 ml / min.