Safety and Efficacy of Anastrozole for the Treatment of Pubertal Gynecomastia: A Randomized, Double-Blind, Placebo-Controlled Trial

Pubertal gynecomastia is thought to result from transient imbalances between estrogen and androgen concentrations. Anastrozole (ARIMIDEX), a potent and selective aromatase inhibitor, decreases estrogen and increases testosterone concentrations in pubertal boys. The safety and efficacy of anastrozole for the treatment of pubertal gynecomastia were evaluated. In a randomized, double-blind, placebo-controlled study of 80 boys, aged 11–18 yr, with pubertal gynecomastia that had not reduced over a 3-month interval, subjects received either anastrozole (1 mg) or placebo once daily for 6 months. A response was defined as a 50% or greater reduction in the calculated volume of both breasts combined using ultrasonography measurements. A comparison of response rates was performed using logistic regression analysis. Secondary end points included changes in serum hormone concentrations. The percentage of patients with a response was 38.5% for the anastrozole group and 31.4% for the placebo group (odds ratio, 1.513; 95...