Drugs that can cause gynecomastia
| DRUG | MECHANISM |
|---|---|
| Amiodarone | Unknown |
| Calcium channel blockers (diltiazem, verapamil, nifedipine) | Unknown |
| Central nervous system agents (amphetamines, diazepam, methyldopa, phenytoin, reserpine, tricyclic antidepressants) | Unknown |
| Cimetidine | Androgen receptor antagonism |
| Cytotoxic agents (alkylating agents, vincristine, nitrosoureas, methotrexate) | Primary hypogonadism due to Leydig cell damage |
| Flutamide | Androgen receptor antagonism |
| Hormones | |
| • Androgens | Aromatization to estrogens; other mechanisms? |
| • Estrogens | Direct stimulation of the breast |
| • Human chorionic gonadotropin | Stimulation of testicular Leydig cell estrogen secretion |
| Isoniazid | Isoniazid |
| Ketoconazole, metronidazole | Inhibition of testosterone synthesis |
| Marijuana | Androgen receptor antagonism |
| D-penicillamine | Unknown |
| Phenothiazines | Elevated serum prolactin |
| Spironolactone | Androgen receptor antagonism; at high doses, interference with testosterone biosynthesis |
| Theophylline | Unknown |
Bembo SA, Carlson HE. Gynecomastia: its features, and when and how to treat it. Cleve Clin J Med 2004;71:511–7.6 Reprinted with permission. Copyright 2004 Cleveland Clinic. All rights reserved.