OBJECTIVES: To investigate the incidence rate of adverse reactions of methimazole in children with hyperthyroidism. METHODS: A retrospective analysis was performed on the medical data of 304 children with hyperthyroidism who were hospitalized in Shengjing Hospital of China Medical University from January 2015 to May 2021. The incidence rate of methimazole-related adverse reactions was analyzed. The risk factors for common adverse reactions were evaluated. RESULTS: Among the 304 children, 87 (28.6%) experienced adverse reactions, among whom there were 20 boys (23%) and 67 girls (77%). Common adverse reactions included neutropenia (12.8%), rash (11.8%), elevated alanine aminotransferase (9.5%), and joint pain (3.0%), and some children experienced multiple adverse reactions simultaneously or intermittently. Neutropenia often occurred within 3 months after administration (25/39, 64%), elevated alanine aminotransferase often occurred within 1 month after administration (17/29, 59%), and rash often occurred within 3 months after administration (30/36, 83%). Most of the above adverse reactions returned to normal after symptomatic treatment. The multivariate logistic regression analysis showed that younger age and lower absolute neutrophil count before treatment were risk factors for neutropenia after methimazole treatment (P<0.05). CONCLUSIONS The adverse reactions of methimazole are common in children with hyperthyroidism, and most adverse reactions occur within 3 months after administration and can be relieved after symptomatic treatment. Children with a younger age or a lower baseline absolute neutrophil count may have a higher risk of neutropenia.
Male ; Child ; Female ; Humans ; Methimazole/adverse effects* ; Antithyroid Agents/adverse effects* ; Retrospective Studies ; Alanine Transaminase ; Hyperthyroidism/chemically induced* ; Neutropenia/chemically induced* ; Exanthema

Among the three treatment modalities of Graves' disease which include antithyroid drug (ATD), radioactive iodine and surgery, the ATD is most commonly preferred in Korea due to ease of use and definite curative effects on the thyrotoxic symptoms. However, several uncertainties about ATD remain: for example, the mechanism of actions on immune modulation, differences in the effects of drugs among individuals and associated factors in the view of remission. In recent years, long-term ATD treatment has been confirmed as an effective and safe therapy modality in adults, and several treatment guidelines have been released which accept long-term ATD therapy as an acceptable alternative to ablative therapy in Graves' patients. In this review, we summarize the recent progress in understanding the clinical role of ATD and emerging new antithyroid drugs focusing on immunomodulation.
Adult ; Antithyroid Agents ; Graves Disease ; Humans ; Immunomodulation ; Iodine ; Korea

Thyrotoxic periodic paralysis (TPP) is a notable and potentially lethal complication of thyrotoxicosis, and Graves' disease is the most common cause of TPP. TPP is commonly reported in Asian males between 20–40 years of age, but it is rare in children and adolescents. We report 2 Korean adolescents (a 16-year-old male and a 14-year-old female) with episodes of TPP who were previously diagnosed with Graves' disease. These 2 patients presented with lower leg weakness in the morning after waking up. They were diagnosed with TPP-associated with thyrotoxicosis due to Graves' disease. After they were initially treated with potassium chloride and antithyroid drugs, muscle paralysis improved and an euthyroid state without muscle paralytic events was maintained during follow-up. Therefore, clinicians should consider TPP when patients have sudden paralysis and thyrotoxic symptoms such as goiter, tachycardia, and hypertension.
Adolescent ; Antithyroid Agents ; Asian Continental Ancestry Group ; Child ; Follow-Up Studies ; Goiter ; Graves Disease ; Humans ; Hypertension ; Hypokalemia ; Hypokalemic Periodic Paralysis ; Leg ; Male ; Paralysis ; Potassium Chloride ; Tachycardia ; Thyrotoxicosis

Whether or not Graves' hyperthyroidism can be really cured, depends on the definition of “cure.” If eradication of thyroid hormone excess suffices for the label “cure,” then all patients can be cured because total thyroidectomy or high doses of 1¹³¹I will abolish hyperthyroidism albeit at the expense of creating another disease (hypothyroidism) requiring lifelong medication with levothyroxine. I would not call this a “cure,” which I would like to define as a state with stable thyroid stimulating hormone (TSH), free thyroxine, and triiodothyronine serum concentrations in the normal range in the absence of any thyroid medication. Surgery and radioiodine are unlikely to result in so-defined cures, as their preferable aim as stated in guidelines is to cause permanent hypothyroidism. Discontinuation of antithyroid drugs is followed by 50% recurrences within 4 years; before starting therapy the risk of recurrences can be estimated with the Graves' Recurrent Events After Therapy (GREAT) score. At 20-year follow-up about 62% had developed recurrent hyperthyroidism, 8% had subclinical hypothyroidism, and 3% overt hypothyroidism related to TSH receptor blocking antibodies and thyroid peroxidase antibodies. Only 27% was in remission, and might be considered cured. If the definition of “cure” would also include the disappearance of thyroid antibodies in serum, the proportion of cured patients would become even lower.
Antibodies ; Antibodies, Blocking ; Antithyroid Agents ; Follow-Up Studies ; Graves Disease ; Humans ; Hyperthyroidism ; Hypothyroidism ; Iodide Peroxidase ; Receptors, Thyrotropin ; Recurrence ; Reference Values ; Thyroid Gland ; Thyroidectomy ; Thyrotropin ; Thyroxine ; Triiodothyronine

A 34-year-old Filipino with Graves' disease on methimazole came in due to fever, sore throat and jaundice. Patient was initially diagnosed with methimazole induced agranulocytosis and drug induced liver injury. She was treated with intravenous broad spectrum antibiotic and granulocyte colony stimulating factor. On day 4 of admission, patient had pancytopenia and was managed as methimazole induced aplastic anemia and was started on steroid therapy and 1 unit of packed red blood cell was transfused. The jaundice also increased hence she was given ursodeoxycholic acid. On day 9 of admission, with the consideration of "lineage steal phenomenon," biopsy was done and eltrompobag was started. Patient was discharged stable at 12th day of hospital admission. This case presents the 3 rarest, life threatening complication of methimazole: agranulocytosis, aplastic anemia and hepatitis. 

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis has been reported in Graves' disease patients treated with antithyroid drugs (ATDs), especially propylthiouracil. ATD-induced ANCA-associated vasculitis usually involved the kidneys followed by the respiratory organs and skin. The treatment of ANCA-associated vasculitis induced by ATDs is to stop ATD therapy immediately, which often leads to an overall good prognosis. We report a case of ANCA-associated vasculitis in the peripheral nerves of the lower extremities in a 66-year-old woman who was treated with methimazole (MMI) for Graves' disease. To our knowledge, this is the third case of peripheral nervous system (PNS) involvement of ATD-induced vasculitis and the first case of PNS vasculitis associated with MMI.
Aged ; Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis ; Antibodies, Antineutrophil Cytoplasmic ; Antithyroid Agents ; Female ; Graves Disease ; Humans ; Kidney ; Lower Extremity ; Methimazole ; Peripheral Nerves ; Peripheral Nervous System ; Prognosis ; Propylthiouracil ; Skin ; Vasculitis

Thyroid dysfunction during pregnancy can result in serious complications for both the mother and infant. However, these complications can be prevented by the optimal treatment of overt maternal thyroid dysfunction. The serum thyroid-stimulating hormone (TSH) concentration is the most reliable measure of thyroid function during pregnancy. Due to the physiologic changes in TSH levels during pregnancy, the correct interpretation of thyroid function requires knowledge of the gestational week and the appropriate population-based reference interval. In addition to a TSH test, the measurement of thyroid peroxidase antibody helps determine whether to treat subclinical hypothyroidism during pregnancy. Since the use of antithyroid drugs during pregnancy is associated with birth defects, it is recommended to discontinue the medication and to perform repeated thyroid function testing during the first trimester. If therapy is needed during the first trimester, propylthiouracil is preferred over methimazole.
Antithyroid Agents ; Congenital Abnormalities ; Female ; Humans ; Hyperthyroidism ; Hypothyroidism ; Infant ; Iodide Peroxidase ; Methimazole ; Mothers ; Pregnancy Trimester, First ; Pregnancy ; Propylthiouracil ; Thyroid Function Tests ; Thyroid Gland ; Thyrotropin

Graves disease is the most common disease that causes hyperthyroidism. It is an autoimmune disease characterized by the overproduction of thyroid hormones due to continuous stimulation of the thyroid gland by thyroid-stimulating hormone receptor antibody. Therapeutic modalities for Graves disease include antithyroid drugs (ATDs), radioactive iodine, and thyroidectomy. ATDs are the most preferred therapeutic option by physicians in most countries except North America. However, current treatment strategies are unfortunately aimed at inhibiting thyroid hormone production or ablating the thyroid to induce permanent hypothyroidism, not at inhibiting thyroid-stimulating hormone receptor antibody. ATD therapy has a high relapse rate (more than 50%), and morbidity and mortality increase in cases of relapse. Therefore, the proper and prompt management of relapsed patients is very important.
Antithyroid Agents ; Autoimmune Diseases ; Graves Disease ; Humans ; Hyperthyroidism ; Hypothyroidism ; Iodine ; Iodine Radioisotopes ; Mortality ; North America ; Recurrence ; Thyroid Gland ; Thyroid Hormones ; Thyroidectomy ; Thyrotropin

A 51-year-old Caucasian male developed Graves’ thyrotoxicosis following long-standing treatment for hypothyroidism. After a short period of treatment with carbimazole, he developed agranulocytosis and required total thyroidectomy. In this relevant case report, we review several pathogenetic mechanisms that explain the transformation of autoimmune hypothyroidism into Graves’ disease and the possible approaches to the management of agranulocytosis secondary to antithyroid medications. Further studies are required to determine the best way to manage severe thyrotoxicosis when agranulocytosis develops due to antithyroid medications.
Hypothyroidism ; Antithyroid Agents ; Carbimazole ; Agranulocytosis

OBJECTIVE: Since Graves' disease (GD) is resistant to antithyroid drugs (ATDs), an accurate quantitative thyroid function measurement is required for the prediction of early responses to ATD. Quantitative parameters derived from the novel technology, single-photon emission computed tomography/computed tomography (SPECT/CT), were investigated for the prediction of achievement of euthyroidism after methimazole (MMI) treatment in GD. MATERIALS AND METHODS: A total of 36 GD patients (10 males, 26 females; mean age, 45.3 ± 13.8 years) were enrolled for this study, from April 2015 to January 2016. They underwent quantitative thyroid SPECT/CT 20 minutes post-injection of (99m)Tc-pertechnetate (5 mCi). Association between the time to biochemical euthyroidism after MMI treatment and %uptake, standardized uptake value (SUV), functional thyroid mass (SUVmean × thyroid volume) from the SPECT/CT, and clinical/biochemical variables, were investigated. RESULTS: GD patients had a significantly greater %uptake (6.9 ± 6.4%) than historical control euthyroid patients (n = 20, 0.8 ± 0.5%, p < 0.001) from the same quantitative SPECT/CT protocol. Euthyroidism was achieved in 14 patients at 156 ± 62 days post-MMI treatment, but 22 patients had still not achieved euthyroidism by the last follow-up time-point (208 ± 80 days). In the univariate Cox regression analysis, the initial MMI dose (p = 0.014), %uptake (p = 0.015), and functional thyroid mass (p = 0.016) were significant predictors of euthyroidism in response to MMI treatment. However, only %uptake remained significant in a multivariate Cox regression analysis (p = 0.034). A %uptake cutoff of 5.0% dichotomized the faster responding versus the slower responding GD patients (p = 0.006). CONCLUSION: A novel parameter of thyroid %uptake from quantitative SPECT/CT is a predictive indicator of an early response to MMI in GD patients.
Antithyroid Agents ; Female ; Follow-Up Studies ; Graves Disease* ; Humans ; Male ; Methimazole* ; Thyroid Gland