- Aromatase inhibitor
- A drug that inhibits the enzyme aromatase and thus lowers the level of the estrogen, estradiol. Aromatase inhibitors are a class of antiestrogens. Aromatase catalyzes the conversion of testosterone (an androgen) to estradiol (an estrogen) in numerous tissues including the adrenal glands, ovaries, placenta, testicles, adipose (fat) tissue, and brain. The growth of many breast cancers is promoted by estrogens. Most estrogen after menopause comes from the action of aromatase. Aromatase inhibitors may therefore be used to treat estrogen-dependent tumors after the menopause.
* * *any one of a class of drugs used in the treatment of advanced breast cancer in postmenopausal women. These drugs act by inhibiting the action of aromatase, an enzyme that promotes the conversion of testosterone to oestradiol. They therefore reduce oestrogen levels, which can be helpful in the control of oestrogen-dependent tumours. Aromatase inhibitors include aminoglutethimide, which requires replacement corticosteroid therapy, and newer drugs, whose side-effects may include any of those due to oestrogen deficiency but which are better tolerated than aminoglutethimide. These drugs include anastrazole (Arimidex), eximestane (Aromasin), formestan (Lentaron), and letrozole (Femara).
Medical dictionary. 2011.