RT Journal Article SR Electronic T1 New aromatase inhibitors for breast cancer JF Drug and Therapeutics Bulletin JO Drug Ther Bull FD BMJ Publishing Group Ltd SP 55 OP 56 DO 10.1136/dtb.1997.35755 VO 35 IS 7 YR 1997 UL http://dtb.bmj.com/content/35/7/55.abstract AB Relevant BNF section: 8.3.4.1â–¼Anastrozole (Arimidex - Zeneca) and â–¼letrozole (Femara - Novartis) are the first selective, oral, non-steroidal aromatase inhibitors. They are licensed for the treatment of advanced breast cancer in postmenopausal women where tamoxifen or other anti-oestrogen therapy has failed. The manufacturers of both drugs claim that their products are more effective, less toxic and better tolerated than the progestogen megestrol acetate, the standard therapy in this clinical situation. We assess these claims.