Ann Pediatr Endocrinol Metab.  2021 Sep;26(3):199-204. 10.6065/apem.2142046.023.

Efficacy and adverse events related to the initial dose of methimazole in children and adolescents with Graves’ disease

• Lee HG
• Yang EM
• Kim CJ

• KMID: 2520513
• DOI: http://doi.org/10.6065/apem.2142046.023

Abstract

Purpose
The first-line antithyroid drug for children and adolescents with Graves’ disease (GD) is methimazole (MMI). This study evaluated the relationship between the initial MMI dose and the clinical course of GD after treatment.
Methods
We studied the efficacy of the initial MMI dose and the relationship between the initial MMI dose and adverse events (AEs). We retrospectively enrolled 22 males and 77 females and divided those subjects into 3 groups according to the initial dose of MMI: <0.4 mg/kg/day (group A; n=32); 0.4–0.7 mg/kg/day (group B; n=39); and >0.7 mg/kg/day (group C; n=28).
Results
The mean time to the normalization of free thyroxine (fT4) levels upon initial treatment was 5.64, 8.61, and 7.98 weeks in groups A, B, and C, respectively (P=0.116). The incidence of liver dysfunction, neutropenia, and skin rash was 12.5%, 20.5%, and 42.9% in groups A, B, and C, respectively (P=0.018). Neutropenia, as a severe AE, was absent in group A, but its prevalence was 7.7% in group B and 21.4% in group C (P=0.015). When comparing only groups B and C, the incidences of liver dysfunction and neutropenia were higher in group C (P=0.04 and P=0.021, respectively).
Conclusion
The mean time to the normalization of fT4 levels did not differ among the 3 groups, but the incidence of AEs was higher in the groups that received high MMI doses. High doses of MMI (>0.7 mg/kg/day) should be reconsidered as an initial treatment for children and adolescents with GD.

Keyword

Methimazole; Adverse events; Graves’ disease; Child

Figure

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  Fig. 1. The time required to normalize free T4 levels after initiating methimazole treatment in patients with Graves’ disease. The mean duration was 5.6±4.2, 8.6±10.4, and 7.9±8.2 weeks in groups A, B, and C, respectively (P=0.116). Group A, initial dose of MMI<0.4 mg/kg/day; group B, 0.4–0.7mg/kg/day; group C, >0.7 mg/kg/day.

Reference

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