Different doses of methimazole treatment of children and adolescents with graves' disease: a clinical study based on 161 cases of outpatients

Objective This study aimed to evaluate the association between the initial dose of MMI and the clinical course, as well as adverse effects on young people with GD.Methods One hundred and sixty-one children and adolescents with newly diagnosed GD were enrolled for this study and categorized into four groups based on initial serum-free T3 and T4 levels and daily MMI doses: Group A (mild, 0.3-0.5 mg/kg/day, n = 78), Group B (moderate, 0.6-0.8 mg/kg/day, n = 37), Group C (severe, 0.6-0.8 mg/kg/day, n = 24), and Group D (severe, 0.8-1.0 mg/kg/day, n = 22). The thyroid function, blood cell analysis and liver function were examined before treatment and at 4, 8 and 12 weeks after treatment. Outcome of long-term follow-up were also observed.Results After 12 weeks of treatment, 91.0% of the patients in group A and 90.9% of the patients in group D recovered to normalization of FT3, which was slightly higher than the other two groups; 70.8% of the patients in group C recovered to normalization of FT4, which was slightly lower than that in the other three groups. The incidence of minor adverse effects was 12.8% in group A, 13.5% in group B, 16.7% in group C and 40.9% in group D (P < 0.01). Remission was achieved in 38 patients (23.6%).Conclusions Lower doses of MMI (0.3-0.5 mg/kg/day) are suitable for mild GD, and higher doses of MMI (0.6-0.8 mg/kg/day) are advisable for moderate or severe GD. Much higher doses of MMI (0.8-1.0 mg/kg/day) are harmful for initial use in children and adolescents with GD patients.