EFFECT OF SINGLE DOSE DEXAMETHASONE ON THE CONCENTRATION OF SERUM TRIIODOTHYRONINE IN MAN

Abstract

In 9 euthyroid volunteers and 6 athyreotic subjects receiving replacement thyroxine therapy, a single dose of dexamethasone caused significant reduction in circulating concentrations of total serum triiodothyronine (T3). The fall was observed 24 hours following the administration of dexamethasone with return to pre-treatment concentrations evident by 48 hours. The reduction in serum T3 in the athyreotic group on replacement thyroxine therapy demonstrates a direct effect of glucocorticoids on the peripheral metabolism of T3 in man.