THE USE OF BILE-ACID SEQUESTRANTS TO LOWER SERUM THYROID-HORMONES IN IATROGENIC HYPERTHYROIDISM

Hyperthyroidism occasionally must be rapidly restored to euthyroidism, especially if it is associated with an emergent condition such as myocardial infarction. Several modalities are available to render endogenous hyperthyroid patients to a euthyroid state rapidly. Few therapeutic options, however, are available to rapidly treat hyperthyroidism caused by ingestion of excess thyroid hormones, except perhaps the use of beta-blockers. We observed hypothyroidism develop in two patients taking stable doses of levothyroxine after cholestyramine was added to their drug regimen. This finding led us to treat two patients with iatrogenic hyperthyroidism with cholestyramine. A euthyroid state was achieved in 72 to 96 hours whereas in three similar patients without cholestyramine treatment it had taken almost 8 days for serum thyroid hormone levels to fall into normal range. Our preliminary results suggest that bile acid sequestrants may be useful in treating exogenous thyroid-hormone-induced hyperthyroidism in emergent situations.