FPGEE for National Association of Boards of Pharmacy (NABP) Practice Exam

Which of the following is a primary characteristic of aromatase inhibitors?

1. They prevent insulin resistance

2. They convert estrogen to testosterone

3. They inhibit the enzyme that converts androgens to estrogens

4. They replace antidiuretic hormone

The correct answer is: They inhibit the enzyme that converts androgens to estrogens

Aromatase inhibitors are a class of drugs that specifically inhibit the aromatase enzyme, which is responsible for the conversion of androgens (such as testosterone and androstenedione) into estrogens (like estradiol and estrone). By blocking this enzymatic activity, aromatase inhibitors effectively reduce estrogen levels in the body. This mechanism is particularly important in the treatment of hormone-sensitive breast cancer, where lowering estrogen levels can help to slow or stop the growth of tumors that are stimulated by estrogen. The other options do not accurately reflect the action of aromatase inhibitors. For instance, preventing insulin resistance pertains to metabolic functions and is unrelated to the primary action of aromatase inhibitors. The statement about converting estrogen to testosterone is the opposite of what aromatase inhibitors do. Additionally, replacing antidiuretic hormone is outside the scope of aromatase inhibitors, as they don't interact with hormones that regulate water balance in the body. Thus, the core characteristic of aromatase inhibitors lies in their role in inhibiting the conversion of androgens to estrogens.