Failure of plasmapheresis, corticosteroids and thionamides to ameliorate a case of protracted amiodarone-induced thyroiditis.

We report a case of amiodarone-induced thyrotoxicosis of protracted duration, unresponsive to conventional thionamide therapy, with therapy limited by severe adverse drug reactions. Other treatment modalities included high dose corticosteroids, plasmapheresis, lithium and perchlorate. Temporary amelioration was achieved following plasmapheresis; however, this and other measures were unsuccessful in controlling the thyrotoxicosis, which deteriorated to thyroid storm. Histopathologically, a degenerative, inflammatory thyroiditis was evident. We discuss the limitations of conventional drug therapy and the lack of a sustained response to plasmapheresis. The failure of high doses steroids to alter the course of illness and to completely suppress the thyroidal inflammatory process is highlighted. A potential role for renal and hepatic impairment in the observed protracted course of amiodarone-induced thyrotoxicosis is suggested.