Comparison of methimazole and propylthiouracil in the management of children and adolescents with Graves' disease: efficacy and adverse reactions during initial treatment and long-term outcome.

OBJECTIVE

The aim of this study was to compare the efficacy and adverse reactions during initial treatment and long-term outcome between children and adolescents with Graves' disease (GD) treated with propylthiouracil (PTU) and those treated with methimazole (MMI).

DESIGN, SETTING AND

PARTICIPANTS

Retrospective and collaborative study. Children and adolescents with GD were divided into group M (MMI: n=64) and group P (PTU: n=69) and into four subgroups by initial dose: group M1 (<0.75 mg/kg of MMI, n=34), group M2 (> or = 0.75 mg/kg, n=30), group P1 (<7.5 mg/kg of PTU, n=24) and group P2 (> or = 7.5 mg/kg, n=45).

MAIN OUTCOME MEASURES: The duration for normalization of serum T4 on initial treatment, the incidence of adverse effects for one year and outcomes at 10 years after were compared.

RESULTS

Mean durations for normalization of T4 (+/- SD) were 1.7 +/- 1.0 months in group M and 2.3 +/- 2.4 in group P [not significant (NS)], while the mean duration in group P1 (3.1 +/- 3.3) was significantly longer than those in the other subgroups (M1: 1.9 +/- 1.2; M2: 1.4 +/- 0.7; P2; 1.7 +/- 1.3). No major adverse reaction was observed. Minor adverse effects occurred in 25.0% of cases in group M and 31.9% in group P (NS). The incidence in group P2 (44.4%) was significantly higher than those in group M1 (20.6%) and group P1 (8.3%). Remission rates did not differ between the MMI-treated group (35.0%, n=20) and PTU-treated group (50.0%, n=40).

CONCLUSIONS

PTU may not be suitable for initial use in children and adolescents with GD, even with the risk of major adverse reactions such as liver failure excluded.