Adjunctive therapy for early invasive breast cancer in post-menopausal women with a positive hormone receptor. Long-term treatment of breast cancer in postmenopausal women with positive hormone receptor who have previously had standard Tamoxifen support. First-line treatment of advanced stage of breast cancer in postmenopausal women. Advanced pediatric cancer in postmenopausal women who are physiologically or artificially induced, previously treated with anti-estrogen drugs in the event of relapse or progression of the disease. The neoadjuvant treatment of HER-2 of negative breast cancer with a positive hormone receptor in postmenopausal women in whom chemotherapy is not appropriate treatment and immediate surgery is not indicated.
Anti-cancer drug - a non-steroidal aromatase inhibitor (an inhibitor of estrogen biosynthesis). Letrozole inhibits aromatase by binding to the hemocyte of the cytochrome P450 enzyme subunit, which in turn leads to a reduction in the level of biosynthesis in all tissues in which it is present. Elimination of the stimulating effect of estrogens is an essential condition to ensure tumor response when the growth of tumor tissue depends on the presence of estrogen and when endocrine treatment is used. LetrozoI is rapidly and completely absorbed from the gastrointestinal tract (bioavailability - 99.9%). Food slightly reduces the rate of absorption of the drug; the preparation can be taken regardless of meals. About 60% is bound to plasma proteins. The main route of elimination of letrozole is metabolism to a pharmacologically inactive metabolite - carbinol - which is mediated by the CYP3A4 and CYP2A6 isoenzymes. The drug is mainly excreted in the urine. T0,5 elimination in plasma is 2 days. Steady state is achieved within 2-6 weeks. Steady state concentrations are approximately 7-fold higher than concentrations measured after a single 2.5 mg dose. Renal impairment (daily creatinine clearance 9-116 ml / min) and mild to moderate hepatic impairment do not affect the pharmacokinetics of Ietrozole. In the case of severe hepatic insufficiency, the availability of the drug and the half-life in the final elimination phase are increased.
Contraindications:
Hypersensitivity to letrozole or other ingredients of the preparation. Premenopausal endocrine status. Pregnancy and breastfeeding.
Precautions:
Use in children is not recommended. For patients with creatinine clearance <10 ml / min, the potential risks / benefits should be considered before the use of letrozole. Exercise caution and consider the potential risk / benefit in patients with varying degrees of hepatic impairment: from mild to moderate to severe. Before starting treatment with Letrozole in women with osteoporosis and / or history of fractures or at risk of osteoporosis, diagnostic tests of bone mineral density - bone densitometry should be carried out, eg by the DEXA method. Patients treated with letrozole should be regularly monitored. In the case of loss of bone mineral density as a result of treatment with Letrozole, appropriate treatment of osteoporosis should be started. 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.
Pregnancy and lactation:
The preparation is contraindicated in pregnant and lactating women. It should only be used in women who have been clearly confirmed to have undergone menopause. Due to reports about the resumption of ovarian function in patients during treatment with letrozole, despite the clearly stated postmenopausal age at the time of starting therapy, the doctor should discuss appropriate methods of contraception with the patient when necessary.
Side effects:
Very often: hypercholesterolemia; hot flushes; increased sweating; arthralgia; fatigue after asthenia. Common: anorexia, increased appetite; depression; pain and dizziness; hypertension; nausea, vomiting, indigestion, constipation, diarrhea, abdominal pain; alopecia, rash (including erythematous rash, papular-maculopapular, psoriasis-like and vesicular), dry skin; muscle pain, bone pain, osteoporosis, bone fractures; bleeding from the genital tract; peripheral edema; weight gain.Uncommon: urinary tract infections; cancer pain (only in the group with metastases in new supportive care); leucopenia; anxiety including irritability and irritability; drowsiness, insomnia, impaired memory, abnormal sensation including paresthesia, hypoesthesia, dysgeusia, cerebrovascular incident; cataracts, eye irritation, blurred vision; palpitations, tachycardia, ischemic heart disease (including new cases or exacerbation of existing angina, angina requiring surgery, myocardial infarction and myocardial ischemia); thrombophlebitis, including superficial and deep vein thrombophlebitis, dyspnea, cough; abdominal pain, stomatitis, dry mouth; increased levels of liver enzymes; pruritus, urticaria; arthritis; increased frequency of urination; vaginal discharge, dryness of the vagina, breast pain; general edema, fever, dry mucous membranes, increased thirst; weight loss.
Dosage:
Orally. Adults and the elderly: the recommended dose is 2.5 mg daily. In patients with advanced breast cancer or metastatic breast cancer, treatment should be continued until there is evidence of tumor progression. In adjuvant therapy and prolonged adjuvant treatment, treatment should be continued for 5 years or until tumor recurrence, whichever occurs first. In adjuvant therapy, a sequential therapy regimen (letrozole for 2 years followed by tamoxifen for 3 years) may also be considered. In neoadjuvant therapy, treatment can be continued for 4 - 8 months to achieve optimal tumor reduction. If there is not enough response, stop using the product and schedule the surgery and / or discuss with the patient further treatment options. No dose adjustment is required in patients with a creatinine clearance ≥ 10 ml / min. There are insufficient data on patients with creatinine clearance ≤ 10ml / min and in patients with acute hepatic failure.
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