Classification: Antineoplastic, hormone
See Also: See also Antineoplastic Agents.
Action/Kinetics: Growth of many breast cancers is due to stimulation of estrogen receptors by estrogens. In postmenopausal women the main source of circulating estrogen is conversion of androstenedione to estrone by aromatase in peripheral tissues with further conversion to estradiol. Anastrozole is a nonsteroidal aromatase inhibitor that significantly decreases serum estradiol levels. Has no effect on formation of adrenal corticosteroids or aldosterone. Well absorbed from the GI tract; food does not affect the extent of absorption. t 1/2 terminal: 50 hr. Metabolized by the liver and both unchanged drug (about 10%) and metabolites are excreted through the urine.
Uses: Advanced breast cancer in postmenopausal women with progression of the disease following tamoxifen therapy. NOTE: Clients with negative tumor estrogen receptors and those who do not respond to tamoxifen are rarely helped by anastrozole.
Special Concerns: Use with caution during lactation. Safety and efficacy have not been determined in children.
Side Effects: GI: N&V, diarrhea, constipation, abdominal pain, anorexia, dry mouth, increased appetite. CNS: Headache, paresthesia, dizziness, depression, somnolence, confusion, insomnia, anxiety, nervousness. CV: Hypertension, thromboembolic disease, thrombophlebitis. Musculoskeletal: Asthenia, back pain, bone pain, myalgia, arthralgia, pathological fracture. Respiratory: Dyspnea, increased cough, pharyngitis, sinusitis, bronchitis, rhinitis. Dermatologic: Hot flushes, rash, sweating, hair thinning, pruritus. GU: Vaginal hemorrhage, UTI, breast pain, vaginal dryness, vaginal bleeding during first few weeks after changing from hormone therapy. Hematologic: Anemia, leukopenia. Miscellaneous: Pain, peripheral edema, pelvic pain, chest pain, weight gain or loss, flu syndrome, fever, neck pain, malaise, accidental injury, infection.
Laboratory Test Alterations: GGT, AST, ALT, alkaline phosphatase, total cholesterol, LDL cholesterol.
How Supplied: Tablet: 1 mg