Adjuvant treatment of post-menopausal women with hormone receptor-positive early breast cancer, and also advanced breast cancer in post-menopausal women. First-line treatment of hormone receptor-positive post-menopausal women who have received 2 to 3 years of adjuvant tamoxifen.
Anastrozole is a non-steroidal aromatase inhibitor. The growth of many cancers of the breast is stimulated or maintained by estrogens. In postmenopausal women, estrogens are mainly derived from the action of the aromatase enzyme, which converts adrenal androgens (primarily androstenedione and testosterone) to estrone and estradiol. The suppression of estrogen biosynthesis in peripheral tissues and in the cancer tissue itself can therefore be achieved by specifically inhibiting the aromatase enzyme.
Adults and elderly: 1 mg tablet to be taken orally once a day.
Co-administration of Anastrozole and tamoxifen in breast cancer patients reduced Anastrozole plasma concentration by 27%. Based on clinical and pharmacokinetic results from the ATAC trial, tamoxifen should not be administered with Anastrozole. Estrogen-containing therapies should not be used with Anastrozole as they may diminish its pharmacological action. In a study conducted in 16 male volunteers, Anastrozole did not alter the exposure (as measured by Cmax and AUC) and anticoagulant activity (as measured by prothrombin time, activated partial thromboplastin time, and thrombin time) of both R- and S-warfarin. Based on in vitro and in vivo results, it is unlikely that co-administration of Anastrozole 1 mg will affect other drugs as a result inhibition of cytochrome P450.
Patients with severe renal impairment (Creatinine clearance less than 20 mL/min), patients with moderate to severe hepatic disease and known hypersensitivity to anastrozole or to any of the excipients. Oestrozen-containing therapies should not be co-administered with anastrazole as they would negate its pharmacological action. There are no data to support the safe use of anastrozole in patients with moderate or severe hepatic impairment, or patients with severe impairment of renal function (creatinine clearance less than 20 mL/min). Women with osteoporosis or at risk of osteoporosis should have their bone mineral density at regular intervals monitored. There are no data available for the use of anastrozole with LHRH analogues. This product contains lactose. Patients with rare hereditary problems of galactose intolerance, the lapp lactase deficiency or glucose-galactose malabsorption should not take this medicine.
More common side effects are: Blurred vision chest pain or discomfort, dizziness, headache nervousness, pounding in the ears, shortness of breath, slow or fast heartbeat, swelling of the feet or lower legs
Anastrozole is contraindicated in pregnant and lactating women.
Clinical trials have been conducted with Anastrozole, up to 60 mg in a single dose given to healthy male volunteers and up to 10 mg daily given to postmenopausal women with advanced breast cancer; these dosages were well tolerated. A single dose of Anastrozole that results in life- threatening symptoms has not been established. In rats, lethality was observed after single oral doses that were greater than 100 mg/kg (about 800 times the recommended human dose on a mg/m2 basis) and was associated with severe irritation to the stomach (necrosis, gastritis, ulceration, and hemorrhage). There is no specific antidote to overdosage and treatment must be symptomatic.
Keep below 30°C temperature, away from light & moisture. Keep out of the reach of children.