Aromatase Inhibitor:This type of medication blocks the enzyme aromatase, which in turn reduces estradiol levels. Aromatase inhibitors are a group of antiestrogen drugs. Aromatase is responsible for transforming certain substances into estradiol, an estrogen, in various tissues such as the adrenal glands, ovaries, placenta, adipose tissue, and brain. While estrogen is directly produced by the ovaries, it is also synthesized by the body with the help of aromatase. Although aromatase inhibitors do not affect ovarian estrogen production, they do limit the body's ability to use aromatase.The development of many breast cancers is fueled by estrogen. After menopause, most estrogen is produced through the action of aromatase. Consequently, aromatase inhibitors can be employed to treat estrogen-dependent cancers in postmenopausal women. These medications are primarily prescribed to women who have undergone menopause since their ovaries cease to produce estrogen.The aromatase inhibitors that have received approval from the US Food and Drug Administration include anastrozole (Arimidex), exemestane (Aromasin), and letrozole (Femara).