Anastrozole (INN) (marketed under the trade name Arimidex by AstraZeneca) is an aromatase-inhibiting drug approved for treatment of breast cancer after surgery, as well as for metastasis in both pre- and post-menopausal women. The severity of breast cancer is increased by oestrogen, as sex hormones cause hyperlasia, and differentiation at oestrogen receptor sites. Anastrozole works by inhibiting the synthesis of the hormone oestrogen. The patent on Arimidex by AstraZeneca expired June 2010.
