|Trade names||Arimidex, Aremed, others|
|Other names||Anastrazole; anastrozol; ICI-D1033; ZD-1033|
|By mouth (tablets)|
|Drug class||Aromatase inhibitor; Antiestrogen|
|Bioavailability||Unknown (but well-absorbed in animals)|
|Metabolism||Liver (~85%) (N-dealkylation, hydroxylation, glucuronidation)|
|Elimination half-life||40–50 hours|
|CompTox Dashboard (EPA)|
|Chemical and physical data|
|Molar mass||293.366 g/mol g·mol−1|
|3D model (JSmol)|
Anastrozole, sold under the brand name Arimidex among others, is a medication used in addition to other treatments for breast cancer. Specifically it is used for hormone receptor-positive breast cancer. It has also been used to prevent breast cancer in those at high risk. It is taken by mouth.
Common side effects of anastrozole include hot flashes, altered mood, joint pain, and nausea. Severe side effects include an increased risk of heart disease and osteoporosis. Use during pregnancy may harm the baby. Anastrozole is in the aromatase-inhibiting family of medications. It works by blocking the production of estrogens in the body, and hence has antiestrogenic effects.
Anastrozole was patented in 1987 and was approved for medical use in 1995. It is on the World Health Organization's List of Essential Medicines, the safest and most effective medicines needed in a health system. Anastrozole is available as a generic medication. The wholesale cost in the developing world is about US$1.92–30.60 a month. In the United States the wholesale cost is about $3.81 per month. In 2016, it was the 224th most prescribed medication in the United States, with more than 2 million prescriptions.