title: Comparison of efficacy and adverse effects between methimazole 15 mg+inorganic iodine 38 mg/day and methimazole 30 mg/day as initial therapy for Graves' disease patients with moderate to severe hyperthyroidism.
abstract: BACKGROUND
  Methimazole (MMI) is usually used at an initial dose of 30 mg/day for severe Graves' disease (GD) hyperthyroidism, but adverse effects are more frequent at this dose than at MMI 15 mg/day.
  
  
  OBJECTIVE
  We designed a regimen to address the lack of a primary therapeutic effect of the MMI 15 mg/day by combining it with inorganic iodine at 38.2 mg/day. Our aim was to compare the two regimens (MMI 15 mg+inorganic iodine at 38.2 mg/day (M15+I) vs. MMI 30 mg/day (M30)) in terms of therapeutic effect, adverse effects, and remission rate.
  
  
  METHODS
  In a prospective study, 310 patients with untreated GD (serum free thyroxine (fT4) ≥5 ng/dL) were assigned to one of the two regimens. Potassium iodide was discontinued in the M15+I group as soon as the serum fT4 level was within the reference range (0.8-1.6 ng/dL).
  
  
  RESULTS
  Percentages of patients achieving an fT4 level within reference range in ≤30, ≤60, or 90 days on the study treatment regimens were 45.3%, 73.9%, and 82.0% respectively for the M15+I group, and 24.8%, 63.1%, and 75.2% respectively for the M30 group. Hence, the proportions of patients achieving this goal in ≤30 or ≤60 days were significantly larger in the M15+I group. Adverse effects that required discontinuation of MMI were more frequent in the M30-treated than in the M15+I-treated group (14.8% vs. 7.5%; p=0.0387). The remission rates in the M15+I and M30 groups were 19.9% and 14.8%-higher in the former, but the difference did not reach statistical significance.
  
  
  CONCLUSIONS
  The results of this study raise the possibility that M15+I is superior to M30 as a primary treatment for moderate to severe hyperthyroidism caused by GD.
authors.affiliation: 1 Department of Internal Medicine, Ito Hospital , Tokyo, Japan .
authors.forename: Shotaro
authors.initials: S
authors.lastname: Sato
authors.forename: Jaeduk Yoshimura
authors.initials: JY
authors.lastname: Noh
authors.forename: Shiori
authors.initials: S
authors.lastname: Sato
authors.forename: Miho
authors.initials: M
authors.lastname: Suzuki
authors.forename: Shigemitsu
authors.initials: S
authors.lastname: Yasuda
authors.forename: Masako
authors.initials: M
authors.lastname: Matsumoto
authors.forename: Yo
authors.initials: Y
authors.lastname: Kunii
authors.forename: Koji
authors.initials: K
authors.lastname: Mukasa
authors.forename: Kiminori
authors.initials: K
authors.lastname: Sugino
authors.forename: Koichi
authors.initials: K
authors.lastname: Ito
authors.forename: Shigenobu
authors.initials: S
authors.lastname: Nagataki
authors.forename: Matsuo
authors.initials: M
authors.lastname: Taniyama
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D013956:Antithyroid Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D002648:Child; D004334:Drug Administration Schedule; D004359:Drug Therapy, Combination; D005260:Female; D006111:Graves Disease / Q000097:blood / Q000188:drug therapy*; D006801:Humans; D008297:Male; D008713:Methimazole / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D008875:Middle Aged; D011193:Potassium Iodide / Q000009:adverse effects / Q000627:therapeutic use*; D013960:Thyroid Function Tests; D013974:Thyroxine / Q000097:blood; D016896:Treatment Outcome; D014284:Triiodothyronine / Q000097:blood; D055815:Young Adult
chemical_list: D013956:Antithyroid Agents; D014284:Triiodothyronine; D011193:Potassium Iodide; D008713:Methimazole; D013974:Thyroxine