title: Remission after potassium iodide therapy in patients with Graves' hyperthyroidism exhibiting thionamide-associated side effects.
abstract: BACKGROUND
  Thionamides have various side effects.
  
  
  OBJECTIVE
  The effectiveness of potassium iodide (KI) was evaluated in hyperthyroid patients who experienced side effects to thionamides.
  
  
  METHODS
  An observational study was conducted at an academic medical center.
  
  
  METHODS
  Among 1388 patients with Graves' hyperthyroidism treated with thionamides, 204 (14.7%) exhibited side effects, and 44 were treated with KI and followed for 17.6 (median; range, 8.6-28.4) years.
  
  
  METHODS
  The primary endpoint was the initial response to KI, and the secondary endpoint was the long-term prognosis.
  
  
  RESULTS
  The conditions of 29 (65.9%) of the 44 patients were well controlled with KI alone (10-400 mg/d) (A group), and 17 (38.6%) patients went into remission after 7.4 (1.9-23.0) years. The conditions of 15 (34.1%) patients were not controlled with KI alone (B group), even at a high dose (100-750 mg/d), but seven patients (15.9%) were controlled with a combination of KI and low-dose thionamides, resulting in remission after 7.2 (2.8-10.8) years. The initial parameters did not predict the response to KI or long-term prognosis. However, remission occurred in 70.8% of the patients treated with less than 200 mg of KI, compared with 35.0% of the patients who required 200 mg or more of KI (P < .05).
  
  
  CONCLUSIONS
  Among hyperthyroid patients with thionamide-associated side effects, KI therapy was effective in two-thirds of cases, and about 40% of the patients experienced remission after KI therapy alone. The chance of remission was small among the patients refractory to KI.
authors.affiliation: Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Okamura
authors.forename: Kaori
authors.initials: K
authors.lastname: Sato
authors.forename: Megumi
authors.initials: M
authors.lastname: Fujikawa
authors.forename: Sachiko
authors.initials: S
authors.lastname: Bandai
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ikenoue
authors.forename: Takanari
authors.initials: T
authors.lastname: Kitazono
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D013956:Antithyroid Agents / Q000009:adverse effects* / Q000627:therapeutic use; D004334:Drug Administration Schedule; D005260:Female; D006111:Graves Disease / Q000188:drug therapy*; D006801:Humans; D008297:Male; D008713:Methimazole / Q000009:adverse effects* / Q000627:therapeutic use; D008875:Middle Aged; D011193:Potassium Iodide / Q000627:therapeutic use*; D011441:Propylthiouracil / Q000009:adverse effects* / Q000627:therapeutic use; D012074:Remission Induction / Q000379:methods; D019233:Retreatment; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D013956:Antithyroid Agents; D011193:Potassium Iodide; D008713:Methimazole; D011441:Propylthiouracil