Gynecomastia in adult males often results from a drug-induced relative imbalance between concentrations of androgens and estrogens. These hormonal changes are induced by certain drugs or by pathological processes interacting with hormonal secretion, the enzymatic systém or with sex steroid receptors. Chronic renal failure, liver disorders, thyrotoxicosis, adrenal hyperplasia or tumours might cause neurohumoral changes that in turn lead to secondary gynecomastia. Several drugs, such as anabolic steroids, digoxin, antihypertensives, some antirheumatic drugs, antidepressants, antiandrogens, neruoleptics and recreational drugs háve been proposed to be responsible for drug-induced gynecomastia. Both phytoestrogens and pollutants háve been also associated with gynecomastia.

        Key words: secondary gynecomastia, drugs.