Astrazeneca manufactured Arimidex is the brand name form of the drug Anastrazole, one of a new type of drug class called aromatase inhibitors which was designed to go over and above the capabilities of the traditional drugs which had been used to treat breast cancer. Arimidex was patented in 1987 and was the first aromatase inhibitor to be used.
In common with other aromatase inhibitors such as Femara and Aromasin, Arimidex has been used by other groups including men suffering from gynecomastia and bodybuilders seeking to minimise estrogen generated by the use of steroids such as testosterone (which convert in part to estrogen). Finally, Arimidex has also been employed in some children to manage precious puberty and pre-pubertal gynecomastia.
Arimidex has been used for decades now and over that time period any uncertainties regarding its safety when it was first introduced have long since elapsed. As a drug that shuts down estrogen formation entirely, it can be considered a level above drugs such as Tamoxifen.
Due to its mechanism of action, Arimidex is suitable only for post-menopausal women suffering from a specific type of breast cancer. However, as noted above, it has been used successfully by both men and children but under very specialised conditions.
Arimidex is generally dosed once daily but doses and how long it is used for will depend of the specific use case for taking it in the first place.