Gynecomastia associated with fenofibrate.

Objective: To report a case of probable fenofibrate-induced gynecomastia.

Case Summary: A 56-year-old white hypercholesterolemic man was treated with fenofibrate 160 mg/day for 1 year. During the course of treatment, he developed gynecomastia on the left side, which resolved after the drug was stopped and replaced with alpha tocopherol acetate. Sixteen months after fenofibrate discontinuation, the patient was rechallenged and subsequently developed gynecomastia symptoms on the right side. The usual etiologies of gynecomastia were excluded by careful assessment of the patient's medical history, physical examination, and results of diagnostic tests such as chest X-ray, mammography, scrotal ultrasonography, routine blood chemistry, and extensive hormonal panel. Gynecomastia again resolved after discontinuation of fenofibrate.

Discussion: In this case, the resolution of gynecomastia on discontinuation of fenofibrate and recurrence after rechallenge highly suggest the role of fenofibrate. Use of the Naranjo probability scale registered causality as probable. Case reports of gynecomastia caused by different drugs have been previously published, but, to our knowledge, this is the first report linking gynecomastia to the use of fenofibrate. The pathogenesis of this adverse drug reaction remains unclear.

Conclusions: Although fenofibrate-induced gynecomastia appears to be uncommon, patients receiving this medication should be monitored for this adverse drug reaction.