title: A stepwise approach to the treatment of amiodarone-induced thyrotoxicosis.
abstract: Amiodarone-induced thyrotoxicosis (AIT) is a complex therapeutic challenge. Two major forms have been described: type I and type II. Methimazole (MMI) and potassium perchlorate (KCLO(4)) is the treatment of choice for the former, whereas corticosteroids are used for the latter. However, mixed forms appear frequently and it is not easy to prescribe corticosteroids because of side effects. The present study investigated the validity of a stepwise therapeutic approach to AIT. Twenty patients with AIT were given 30-50 mg/d of MMI and 1000 mg/d of KCLO(4) initially for a month. Euthyroidism or a significant decrease in serum thyroid hormone levels could be achieved in 12 of the patients (7 with type I, 5 type II). Prednisolone, 40-48 mg/d was added for the 8 nonresponding patients (7 type I, 1 type II) and euthyroidism was achieved in all. The prednisolone dose was decreased when free thyroxine (T(4)) levels normalized, and MMI was titrated, maintaining euthyroidism until urinary iodine excretion normalized. Mixed forms of AIT may prevail in iodine-deficient areas. Initial classification of the patients may cause unnecessary corticosteroid use in a substantial number of patients with AIT. A stepwise approach is feasible; however, when the patient is gravely ill, MMI, KCLO(4), and prednisolone could be prescribed simultaneously.
authors.affiliation: Department of Endocrinology and Metabolism, Ankara University, Medical Faculty, Ankara, Turkey. murat.erdogan@temd.org.tr
authors.forename: Murat Faik
authors.initials: MF
authors.lastname: Erdogan
authors.forename: Sadi
authors.initials: S
authors.lastname: Güleç
authors.forename: Eralp
authors.initials: E
authors.lastname: Tutar
authors.forename: Nilgün
authors.initials: N
authors.lastname: Başkal
authors.forename: Gürbüz
authors.initials: G
authors.lastname: Erdogan
mesh_terms: D000638:Amiodarone / Q000009:adverse effects*; D000889:Anti-Arrhythmia Agents / Q000009:adverse effects*; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use; D000906:Antibodies / Q000032:analysis; D013956:Antithyroid Agents / Q000008:administration & dosage / Q000627:therapeutic use; D005260:Female; D006801:Humans; D007454:Iodides / Q000652:urine; D007455:Iodine / Q000172:deficiency*; D008297:Male; D008713:Methimazole / Q000008:administration & dosage / Q000627:therapeutic use; D008875:Middle Aged; D010472:Perchlorates / Q000627:therapeutic use; D017680:Potassium Compounds / Q000627:therapeutic use; D011239:Prednisolone / Q000627:therapeutic use; D011446:Prospective Studies; D013961:Thyroid Gland / Q000000981:diagnostic imaging; D013971:Thyrotoxicosis / Q000139:chemically induced* / Q000000981:diagnostic imaging / Q000188:drug therapy*; D013974:Thyroxine / Q000097:blood; D014463:Ultrasonography
chemical_list: D000889:Anti-Arrhythmia Agents; D000893:Anti-Inflammatory Agents; D000906:Antibodies; D013956:Antithyroid Agents; D007454:Iodides; D010472:Perchlorates; D017680:Potassium Compounds; C009006:potassium perchlorate; D008713:Methimazole; D007455:Iodine; D011239:Prednisolone; D000638:Amiodarone; D013974:Thyroxine