Iatrogenic Causes of Gynecomastia

Medication-Induced Gynecomastia

Ketoconazole can cause hypogonadism and gynecomastia in men, which may limit prolonged treatment 1
Estrogens and medications with estrogenic activity directly stimulate breast tissue growth, according to the European Urology guidelines 2
Testosterone or androgenic anabolic steroids can cause gynecomastia through conversion to estrogens, as reported by the European Urology guidelines 2
Progestogens, including cyproterone acetate, can contribute to gynecomastia, as stated by the European Urology guidelines 2
5-alpha reductase inhibitors (finasteride, dutasteride) may cause gynecomastia, according to the European Urology guidelines 2
Gonadotropin-releasing hormone (GnRH) agonists or antagonists can lead to gynecomastia, as reported by the European Urology guidelines 2
Hyperprolactinemia-inducing drugs can cause gynecomastia, according to the European Urology guidelines 2
Glucocorticoids may contribute to gynecomastia, as stated by the European Urology guidelines 2

Exogenous estrogens used for various conditions can directly stimulate breast tissue growth, according to the European Urology guidelines 2
Androgen receptor blockers (steroidal antiandrogens, cyproterone acetate, spironolactone) can cause gynecomastia, as reported by the European Urology guidelines 2
Non-steroidal antiandrogens (flutamide, bicalutamide, nilutamide) commonly used in prostate cancer treatment can lead to gynecomastia, according to the European Urology guidelines 2

Surgical hypophysectomy can lead to hormonal imbalances resulting in gynecomastia, as reported by the European Urology guidelines 2
Pituitary or cranial irradiation may affect hormone production, leading to gynecomastia, according to the European Urology guidelines 2

Digoxin has evidence that is contradictory regarding sex-specific adverse effects, including gynecomastia, in patients with heart failure 3
For patients requiring mineralocorticoid receptor antagonists (MRAs) who develop gynecomastia on spironolactone, the American College of Cardiology recommends switching to eplerenone as it has a significantly lower risk of this side effect 4, 5
When evaluating male patients with breast enlargement, consider both true gynecomastia (glandular tissue proliferation) and pseudogynecomastia (fatty tissue deposition), especially in patients with elevated BMI, according to the American College of Radiology 6
In heart failure patients, the absolute difference in gynecomastia rates between MRA users and placebo is relatively small (approximately 0.9%), primarily attributed to spironolactone rather than eplerenone, as reported by the American College of Cardiology 4, 5
Male patients receiving androgen deprivation therapy (ADT) for prostate cancer commonly experience gynecomastia, with incidence as high as 80% in those on estrogen therapy, according to the National Comprehensive Cancer Network 7

Chronic cannabis use, especially when started at a young age, may have significant effects on hormonal systems, according to the Annals of Internal Medicine guidelines 8