Comparison of methimazole and propylthiouracil in patients with hyperthyroidism caused by Graves' disease.
BACKGROUND
Although methimazole (MMI) and propylthiouracil (PTU) have long been used to treat hyperthyroidism caused by Graves' disease (GD), there is still no clear conclusion about the choice of drug or appropriate initial doses.


OBJECTIVE
The aim of the study was to compare the MMI 30 mg/d treatment with the PTU 300 mg/d and MMI 15 mg/d treatment in terms of efficacy and adverse reactions.


METHODS
Patients newly diagnosed with GD were randomly assigned to one of the three treatment regimens in a prospective study at four Japanese hospitals.


METHODS
Percentages of patients with normal serum free T(4) (FT4) or free T(3) (FT3) and frequency of adverse effects were measured at 4, 8, and 12 wk.


RESULTS
MMI 30 mg/d normalized FT4 in more patients than PTU 300 mg/d and MMI 15 mg/d for the whole group (240 patients) at 12 wk (96.5 vs. 78.3%; P = 0.001; and 86.2%, P = 0.023, respectively). When patients were divided into two groups by initial FT4, in the group of the patients with severe hyperthyroidism (FT4, 7 ng/dl or more, 64 patients) MMI 30 mg/d normalized FT4 more effectively than PTU 300 mg/d at 8 and 12 wk and MMI 15 mg/d at 8 wk, respectively (P < 0.05). No remarkable difference between the treatments was observed in patients with initial FT4 less than 7 ng/dl. Adverse effects, especially mild hepatotoxicity, were higher with PTU and significantly lower with MMI 15 mg/d compared with MMI 30 mg/d.


CONCLUSIONS
MMI 15 mg/d is suitable for mild and moderate GD, whereas MMI 30 mg/d is advisable for severe cases. PTU is not recommended for initial use.
Nakamura
Hirotoshi
H
Department of Internal Medicine II, Hamamatsu University School of Medicine, Handayama 1-20-1, Hamamatsu, Shizuoka, Japan. hirotosh@hama-med.ac.jp
Noh
Jaeduk Yoshimura
JY
Itoh
Koichi
K
Fukata
Shuji
S
Miyauchi
Akira
A
Hamada
Noboru
N
D000328:Adult; D013956:Antithyroid Agents / Q000008:administration & dosage* / Q000009:adverse effects; D005260:Female; D006111:Graves Disease / Q000097:blood / Q000150:complications / Q000188:drug therapy*; D006801:Humans; D006980:Hyperthyroidism / Q000097:blood / Q000188:drug therapy* / Q000209:etiology; D008297:Male; D008713:Methimazole / Q000008:administration & dosage* / Q000009:adverse effects; D011441:Propylthiouracil / Q000008:administration & dosage* / Q000009:adverse effects; D011446:Prospective Studies; D013974:Thyroxine / Q000097:blood; D016896:Treatment Outcome; D014284:Triiodothyronine / Q000097:blood
D013956:Antithyroid Agents; D014284:Triiodothyronine; D008713:Methimazole; D011441:Propylthiouracil; D013974:Thyroxine