Aromatase inhibitors are compounds that block
aromatase which converts
androgens to
estrogens. These compounds have been investigated for many years in a variety of conditions in which
estrogen blockade is desired. During the past decade, a third generation of
aromatase inhibitors has been developed with a much more potent blockade of the
enzyme and less side effects. These new
aromatase inhibitors are well absorbed after
oral administration and, because of a long half life, are given once daily, thereby increasing compliance. The use of
aromatase inhibitors is approved for the treatment of
estrogen responsive
breast cancer.
Estrogens play a major role in bone maturation and growth plate fusion in both sexes. Therefore, inhibition of
estrogen production may increase final height in a number of conditions where the final height is compromised. Due to their ability to block
estrogen production, a number of clinical studies have been conducted to investigate their efficiency in a range of situations where
estrogen blockade is desired. These include: peripheral
precocious puberty secondary to
congenital adrenal hyperplasia, familial male-dominant
precocious puberty, and
McCune-Albright syndrome, short stature in boys secondary to
growth hormone deficiency, familial/genetic short stature, constitutional growth delay or idiopathic short stature. The use of
aromatase inhibitors has been investigated also in pubertal
gynecomastia. It is important to emphasize that this treatment, although it seems to be safe and encouraging, is still investigational and is not yet approved for routine usage.