Arimidex is an aromatase inhibitor approved for adjuvant (post-surgery) treatment of hormone receptor-positive (HR+) early breast cancer and first-line or subsequent treatment of HR+ advanced or metastatic breast cancer in postmenopausal women.
The female hormone estrogen stimulates the growth of hormone-receptor-positive breast cancer. Aromatase inhibitors block an enzyme that converts other hormones, known as androgens, into estrogen. They do not stop the ovaries from producing estrogen, so premenopausal women should only use them with other drugs that suppress ovarian function.
Studies show that aromatase inhibitors like Arimidex work better than tamoxifen for reducing the risk of recurrence after the initial treatment of early breast cancer with surgery, radiation, or chemotherapy. Arimidex was first approved in 1995.
Dosing Info: Arimidex is taken as a once-daily tablet.
Common side effects include hot flashes, muscle and joint pain, vaginal dryness, nausea and vomiting, headache, skin rash, and swelling. Potential serious side effects include cardiovascular problems, bone loss (osteoporosis), and elevated cholesterol. Arimidex should not be used during pregnancy.