In case of suspected drug-induced gynecomastia, it would be opportune considering a therapy discontinuation. In some cases, it could be helpful reducing the doses or substituting the suspected drug with another one belonging to the same class, but with a weaker association to gynecomastia. 3
Mammography scan allows distinguishing with certainty between gynecomastia and pseudogynecomastia. On the other hand, laboratory tests are necessary for identifying other possible causes, checking the renal, hepatic and thyroid functions and the free-circulating hormones levels. 2
Iatrogenic gynecomastia is generally reversible within 6 months or one year since its onset. If drug discontinuation is not enough or not possible (for example with anti-androgens), a therapy based on tamoxifene (20 mg daily) might be taken into consideration. In fact, despite not being approved for this indication, literature data suggest a response rate of 50-80% of cases, with detectable improvements from the first month of treatment. 3 In the rare eventuality of both drug dechallenge and tamoxifene therapy being unsuccessful, it is possible to resort to surgery or radiotherapy, according to the patient’s needs.
Gynecomastia is a common adverse effect of bicalutamide (Casodex) therapy that may prompt some men to discontinue prostate cancer treatment. Tamoxifen has been recommended as a preventive agent for gynecomastia in these patients. A double-blind study of 282 men randomized to receive 20 mg of tamoxifen once per day with bicalutamide or bicalutamide alone found that after six months, gynecomastia and breast pain were significantly reduced in men who received tamoxifen ( versus percent in the control group). 41 An Italian randomized controlled trial of 80 participants also found that 20 mg of tamoxifen once per week is as effective as 20 mg once per day. 42