Control of Graves\u2019 hyperthyroidism with very long-term methimazole treatment: a clinical trial

Fereidoun Azizi,Atieh Amouzegar,Hengameh Abdi

doi:10.1186/s12902-020-00670-w

Abstract

BackgroundLong-term antithyroid drug therapy has become one of the options for treatment of Graves’ hyperthyroidism. The aim of this study was to compare thyroid status in those who discontinued methimazole (MMI) treatment after 12.8 years with those who continued MMI as long as 24 years.MethodsFifty nine patients with Graves’ disease on long-term MMI for 14.2 ± 2.9 years were recruited; 32 patients (54%) decided to discontinue MMI and 27 (46%) preferred additional years of MMI treatment. All patients were followed for a mean of 6 additional years.ResultsOf 27 patients who continued MMI up to 24 years, suppressed serum thyrotropin (TSH) was not observed in any patient after the seventh year of treatment. Serum free thyroxine, triiodothyronine, TSH and TSH receptor antibody concentrations remained normal up to the length of the study. Mean daily dose of MMI to maintain TSH in the reference range decreased gradually and reached to 2.8 ± 1.7 mg by 24 years of MMI treatment. No adverse reaction related to MMI occured during additional years of therapy. In 32 patients who discontinued MMI, hyperthyroidism relapsed in 6 patients (19%), one left follow-up and 25 (78%) remained euthyroid during the study.ConclusionsLong-term low dose MMI treatment may be a lifelong effective and safe therapeutic modality in patients with Graves’ hyperthyroidism for prevention of relapse, if studies from other centers confirm findings of this research.Trial registrationIRCT201009224794N1, 2010-10-25. Retrospectively registered.https://www.irct.ir/trial/5143.

Highlights

Antithyroid thionamide drugs (ATDs) have become the treatment of choice for Graves’ disease (GD) in the United States, and majority of patients in other countries worldwide [1,2,3]
A few studies from different regions of the world have adopted the long-term continuous ATD therapy [6,7,8,9,10]; based on findings of a meta-analysis, remission rate increases by 16% for each additional year of ATD therapy after 24 months of ATD treatment [11]. These findings indicate that failure to attain normal TRAb concentrations after conventional 12–18 months of ATD treatment does not rule out the possibility of remission over a long-term ATD therapy [12]; long-term treatment of
A recent randomized clinical trial reported that 5-year continuous methimazole (MMI) therapy is accompanied with 84% remission up to 4 years after drug withdrawal [14]

Summary

Introduction

Antithyroid thionamide drugs (ATDs) have become the treatment of choice for Graves’ disease (GD) in the United States, and majority of patients in other countries worldwide [1,2,3]. A few studies from different regions of the world have adopted the long-term continuous ATD therapy [6,7,8,9,10]; based on findings of a meta-analysis, remission rate increases by 16% for each additional year of ATD therapy after 24 months of ATD treatment [11]. We aimed to compare thyroid status in patients who discontinued MMI treatment after 12.8 years with those who continued MMI therapy for as long as 24 years. Long-term antithyroid drug therapy has become one of the options for treatment of Graves’ hyperthyroidism. The aim of this study was to compare thyroid status in those who discontinued methimazole (MMI) treatment after 12.8 years with those who continued MMI as long as 24 years

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