Acute ingestions of thyroid hormones.

Although thyroid medications are commonly prescribed, there are only nine case reports describing the consequences of acute excessive ingestion of thyroid hormones. Two additional cases are presented and the prior nine cases are reviewed. The potential for toxicity is discussed in relationship to the cellular mechanisms of action of thyroid hormones. Although the potential for toxicity is low, the following therapy is recommended to decrease further the toxic potential: (1) lavage and activated charcoal to decrease absorption, (2) cholestyramine to decrease enterohepatic circulation (3) prednisone and/or propylthiouracil to decrease conversion of thyroxine to triiodothyronine, and (4) propranolol to block metabolic effects. If symptoms of toxicity develop, then attempts to remove thyroid hormones should be undertaken using exchange transfusion.