Changes in circulating iodothyronines in euthyroid and hyperthyroid subjects given ipodate (Oragrafin), an agent for oral cholecystography.

A dose (3 g) of sodium ipodate used routinely in oral cholecystography caused a fall in serum 3,5,3'-triiodothyronine and a rise in serum 3,3',5'-triiodothyronine in three patients taking thyroxine (T4), four euthyroid subjects,and four hyperthyroid patients. Serum T4 fell in patients with hperthyroidism, whereas it rose in the other two groups. Sodium ipodate appears to alter peripheral T4 metabolism and, in addition, produces thyroid-inhibiting effects in hyperthyroidism.