Aromatase inhibitors for male infertility

• Published in: Fertility and sterility Vol. 98; no. 6; pp. 1359 - 1362
• Main Author: Schlegel, Peter N., M.D
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01-12-2012; Elsevier
• Subjects: adverse effects; Aromatase Inhibitors - therapeutic use; Biological and medical sciences; Birth control; blood serum; estradiol; Evidence-Based Medicine; Gynecology. Andrology. Obstetrics; Humans; Infertility, Male - drug therapy; Infertility, Male - epidemiology; Infertility, Male - prevention & control; Internal Medicine; Male; male fertility; males; Medical sciences; men; Obstetrics and Gynecology; Prevalence; randomized clinical trials; Risk Factors; spermatogenesis; spermatozoa; Sterility. Assisted procreation; testosterone; Treatment Outcome; unspecific monooxygenase; Male sterility; Aromatase inhibitor; Male genital diseases; Obstetrics; Gynecology
• ISSN: 0015-0282; 1556-5653
• DOI: 10.1016/j.fertnstert.2012.10.023

Some men with severely defective sperm production commonly have excess aromatase activity, reflected by low serum testosterone and relatively elevated estradiol levels. Aromatase inhibitors can increase endogenous testosterone production and serum testosterone levels. Treatment of infertile males with the aromatase inhibitors testolactone, anastrazole, and letrozole has been associated with increased sperm production and return of sperm to the ejaculate in men with non-obstructive azoospermia. Use of the aromatase inhibitors anastrazole (1 mg/day) and letrozole (2.5 mg/day) represent off-label use of these agents for impaired spermatogenesis in men with excess aromatase activity (abnormal testosterone/estradiol [T/E] ratios). Side effects have rarely been reported. Randomized controlled trials are needed to define the magnitude of benefit of aromatase inhibitor treatment for infertile men.