A 60-year-old man comes to the office for a significant increase in the size of his breasts. He has a history of obstructive urinary symptoms due to benign prostatic hyperplasia that were unrelieved with tamsulosin, and a new medication was prescribed at his last visit 8 months ago. Since starting the new medication, the patient has experienced gradual improvement in urinary hesitancy and strength of urinary stream. The patient reports no pain or changes in weight. Glandular tissue, approximately 2 cm in diameter, is palpated under the nipples and is mildly tender to palpation. There is no nipple discharge, breast asymmetry, or rash. This patient's breast findings are most likely due to which of the following drug effects?

Question

A 60-year-old man comes to the office for a significant increase in the size of his breasts. He has a history of obstructive urinary symptoms due to benign prostatic hyperplasia that were unrelieved with tamsulosin, and a new medication was prescribed at his last visit 8 months ago.  Since starting the new medication, the patient has experienced gradual improvement in urinary hesitancy and strength of urinary stream.  The patient reports no pain or changes in weight.  Glandular tissue, approximately 2 cm in diameter, is palpated under the nipples and is mildly tender to palpation.  There is no nipple discharge, breast asymmetry, or rash.  This patient's breast findings are most likely due to which of the following drug effects?

Quizplus · Accepted Answer

Eductional Objective: 5-alpha reductase inhibitors (eg, finasteride, dutasteride) are used in the treatment of benign prostatic hyperplasia.  They block the conversion of testosterone to dihydrotestosterone; the excess testosterone is then available for conversion to estrogens (eg, estradiol) by aromatase, which can lead to gynecomastia.

A 60-Year-Old Man Comes to the Office for a Significant