Efavirenz-associated gynecomastia: report of five cases and review of the literature.

The prognosis of HIV infection has improved dramatically since the introduction of highly active antiretroviral therapy (HAART). However, numerous adverse effects and limitations regarding tolerability remain a concern. Lipomastia (pseudogynecomastia), a breast enlargement due to central adiposity, may occur as part of a fat redistribution syndrome which has been associated with HAART regimens and several pathogenic mechanisms have been advocated in its development. Here we report an observational longitudinal study of five patients diagnosed of gynecomastia associated with efavirenz-based HAART regimens. All cases reached successful immunologic and virologic responses to HAART. The delay of appearance of gynecomastia from the beginning of HAART ranged between 4 to 15 months. In all five cases, gynecomastia regressed after efavirenz withdrawal (mean period of 5 months). In summary, we think that HAART induced gynecomastia should be suspected in HIV patients receiving efavirenz-containing regimens. Although pathogenesis is unclear, this study and a review of the English literature implicates two possible mechanisms: (a) immune restoration processes and (b) efavirenz mediated estradiol-like effects.