Impact of methimazole-induced hypothyroidism on postnatal swine

Thyroid hormones regulate metabolic rate, nutrient utilization, growth, and development. Swine are susceptible to thyroid suppression in response to disease or environmental conditions, but the physiological impact of such disruption has not been established. The objective of this study was to evaluate the impact of hypothyroidism induced with the antithyroid medication methimazole (MMI). 10 mg/kg MMI significantly decreased circulating triiodothyronine (T3) for the duration of treatment but had only a transient effect on circulating thyroxine (T4). Thyroid tissue weight was significantly increased by more than 3.5-fold in response to MMI treatment. Histologically, the eosinophilic colloid was largely absent from the thyroid follicle which displayed a disorganized columnar epithelium consistent with goiter. MMI induced hypothyroidism has no effect on growth rate over 28 days. Hepatic expression of genes associated with thyroid metabolism (DIO1, DIO2, and DIO3), lipid utilization (CD36, FASN, and ACACA), apoptosis (TP53, PERP, SIVA1, and SFN) and proliferation (CDK1, CDK2, CDK4, and CDKN1A) were unaffected by treatment. Collectively these results demonstrate that MMI induces mild systemic hypothyroidism and pronounced goiter, indicating a strong homeostatic central regulation within the hypothalamic pituitary thyroid axis. This combined with limited peripheral effects, indicates resilience to hypothyroidism in modern swine.

An unusual evolution of thyroid function after therapeutic plasma exchange in Graves' disease with cholestatic jaundice: A case report

RATIONALE

Methimazole (MMI) is the first-line agent in the treatment of hyperthyroidism. However, rare but severe cholestatic jaundice may occur. Therapeutic plasma exchange (TPE) may provide an alternative treatment for such patients and they received thyroidectomy/radioactive iodine ablation or continued oral anti hyperthyroidism medication immediately after TPE session in the reported literatures. The case reported here is, to our knowledge, the first to describe the long interval between anti hyperthyroidism therapy and TPE in such patients.

PATIENT CONCERNS

A 49-year-old Chinese woman had developed worsening jaundice 3 weeks after receiving methimazole (20 mg/day) for the treatment of hyperthyroidism secondary to Graves' disease (GD). Additionally, she had a 2-year history of type 2 diabetes.

DIAGNOSIS

Hyperthyroidism secondary to GD, MMI-induced severe cholestatic jaundice and type 2 diabetes.

INTERVENTIONS

Methimazole was discontinued and the patient received 3 times of TPE, about 3-month glucocorticoid treatment, insulin administration accordingly and other conventional liver-protecting therapy.

OUTCOMES

Her thyroid function was stabilized with small dose of thyroxine substitution and euthyroid status persisted after thyroxine discontinuation until hyperthyroidism recurred 7 months later while her cholestatic jaundice was eventually recovered by about 3-month glucocorticoid therapy.

LESSONS

Due to the complex interplay between liver function and thyroid hormones, there may be unusual changes of thyroid function in GD patients with severe liver injury after TPE. By this case, we want to highlight the importance of a closely following up of thyroid function in order to deliver appropriate health suggestions for patients.

A review on nondiabetic hypoglycemia from various causes: Case series report

RATIONALE

Hypoglycemia is common in patients with glucose regulation disorders and related diabetic treatments but is rare in nondiabetic patients. Severe hypoglycemia can cause harm to patients' cognition, consciousness, central nervous system, cardiovascular and cerebrovascular system, and even death. However, the most fundamental way to control hypoglycemia is to identify the cause and deal with the primary disease. This article introduces 3 cases of nondiabetic hypoglycemia with different causes, aiming to improve our understanding of nondiabetic hypoglycemia and improve the ability of early diagnosis and differential diagnosis.

PATIENT CONCERNS

Case 1 is a 19-year-old female with a history of recurrent coma, and magnetic resonance imaging and endoscopic ultrasound of the pancreas suggest insulinoma. Case 2 is a 74-year-old male with a history of viral hepatitis, and computerized tomography shows multiple nodules in the liver, which is diagnosed as liver cancer. Case 3 is a 39-year-old female with a history of taking methimazole, who tested positive for insulin antibodies, and was diagnosed with insulin autoimmune syndrome.

DIAGNOSIS

All 3 patients were diagnosed with nondiabetic hypoglycemia, but the causes varied, and included insulinoma, non-islet cell tumor-induced hypoglycemia, and insulin autoimmune syndrome.

INTERVENTIONS

Case 1 underwent pancreatic tail resection; case 2 refused anti-tumor treatment and received glucose injections for palliative treatment only; and case 3 stopped taking methimazole.

OUTCOMES

After surgery, the blood sugar in case 1 returned to normal, and the blood sugar in case 2 was maintained at about 6.0 mmol/L. The symptoms of hypoglycemia gradually improved in case 3 after stopping the medication.

LESSONS

Non-diabetic hypoglycemia requires further examination to clarify the cause, and the correct differential diagnosis can provide timely and effective treatment, improving the patient's prognosis.

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.

Short- and long-term outcomes of patients with hyper or hypothyroidism following COVID vaccine

Since the beginning of the wide-scale anti-Coronavirus disease 2019 (COVID-19) vaccination program, sporadic cases of thyroid disease following vaccination have been reported. We describe 19 consecutive cases of COVID vaccine-related thyroid disease. Medical records were reviewed for 9 patients with Graves' disease (GD) and 10 with Thyroiditis, all of whom were diagnosed following COVID-19 vaccination. In the GD group, the median age was 45.5 years, female/male(F/M) ratio 5:4, thyroid-stimulating immunoglobulins were elevated in seven patients. The median time from vaccination to diagnosis was 3 months. Methimazole treatment was given to all but one patient. At a median follow-up of 8.5 months from vaccination, three patients were still on methimazole, five went into remission (data were missing for one). In the Thyroiditis group, the median age was 47 years, the F/M ratio 7:3. Thyroiditis was diagnosed after the first, second, and third doses in one, two, and seven patients, respectively. The median time from vaccination to diagnosis was 2 months. TPO antibodies were positive in three patients. All patients were euthyroid off medication at the last visit. Six patients were diagnosed in the hypothyroid phase at 2.5 months from vaccination. Four resolved spontaneously at 3, 6, 4, and 8 months; the other two were treated with thyroxine at 1.5 and 2 months from vaccination and remained on treatment at their last visit, at 11.5 and 8.5 months, respectively. Thyroid disease should be included among possible complications of COVID-19 vaccine and either a late onset or delayed diagnosis should be considered.

[Leukocytoclastic vasculitis as an adverse effect of propylthiouracil. A case report]

BACKGROUND

The most common cause of hyperthyroidism is Graves' disease. Propylthiouracil (PTU) is one of the drugs used to treat this disease. Leukocytoclastic vasculitis is described among dermatologic adverse effects of PTU.

CASE REPORT

A 18-year-old woman, allergic to methimazole, developed a vasculitis associated to ANCAs with characteristics of leukocytoclastic vasculitis, associated to PTU treatment. She did not present systemic involvement. PTU treatment was suspended. Two months later, the skin lesions had almost completely resolved.

CONCLUSIONS

Leukocytoclastic vasculitis should be considered in the spectrum of complications caused by the consumption of propylthiouracil. The lesions can manifest over time, from a few weeks to years after taking the drug. When there is no systemic involvement, propylthiouracil suspension is sufficient to cure the disease.

Incidence of and Risk Factors for Neonatal Hypothyroidism Among Women with Graves' Disease Treated with Antithyroid Drugs Until Delivery

Background: The incidence of neonatal hypothyroidism among newborns born to mothers with Graves' disease (GD) who continued antithyroid drug (ATD) treatment until delivery has never been reported. Objective: Our primary objective was to investigate the incidence of neonatal hypothyroidism among newborns born to mothers with GD who were treated with ATD until delivery. Our secondary objective was to identify the cutoff ATD daily doses for neonatal hypothyroidism risk, based on maternal thyrotropin (TSH) receptor antibody (TRAb) levels. Methods: We conducted a retrospective cohort study. We included 305 pregnant women with GD who were treated with an ATD until delivery (63 treated with methimazole [MMI] and 242 treated with propylthiouracil [PTU]). Umbilical cord TSH, free thyroxine (fT4), and TRAb levels were measured at delivery, and we investigated the respective relationships between neonatal hypothyroidism at delivery and maternal fT4 levels, TRAb levels, and daily ATD doses during pregnancy. Neonatal hypothyroidism was diagnosed when the umbilical cord fT4 level was below the lower limit of the reference range. Results: The incidence of neonatal hypothyroidism at delivery was 19.0% ([confidence interval, CI, 11.2-30.4]; 12/63) in the MMI group and 12.8% ([CI, 9.2-17.6]; 31/242) in the PTU group. Neonatal goiter was observed in one neonate in the PTU group, and two infants in the PTU group required levothyroxine treatment. The daily ATD dose in the third trimester was the strongest predictor of neonatal hypothyroidism at delivery; the cutoff MMI dose was 10 mg/day, and the cutoff PTU dose was 150 mg/day. When the maternal TRAb level in the third trimester was above three times the upper limit of the normal range, the cutoff MMI dose was 20 mg/day, and the cutoff PTU dose was 150 mg/day. Conclusions: Maternal fT4 and TRAb levels were higher in the neonatal hypothyroid group, which suggested prolonged GD activity. Careful follow-up is necessary when maternal GD remains active and the ATD dose to control maternal thyrotoxicosis cannot be reduced.

Long-term thionamide antithyroid treatment of Graves' disease

Thionamide antithyroid drugs (ATD) are the treatment of choice for Graves' hyperthyroidism. The major drawback of ATD treatment for 1-2 years is the relapse of hyperthyroidism in about 50% of patients. Recently, it has been shown that ATD treatment for more than five years is accompanied by long-term remission in majority of patients without additional major side effects in both adults and children. Compared to radioactive iodine therapy, long-term ATD results in more favorable outcomes. This review summarizes the evidence on long-term ATD therapy regarding the remission rate of hyperthyroidism, efficacy and safety, indications and mode of therapy in patients with hyperthyroidism.

Efficacy of methimazole before the administration of radioactive iodine in the management of Graves' disease: a systematic review and meta-analysis

BACKGROUND

The efficacy of anti-thyroid drugs in conjunction with radioactive iodine therapy in the management of Graves' disease is still controversial.

OBJECTIVE

To compare the efficacy of pretreatment with methimazole before the administration of radioactive iodine for the treatment of Graves' disease.

DESIGN AND SETTING

A systematic review and meta-analysis was conducted at a teaching/tertiary hospital in Ibadan, Nigeria.

METHODS

A systematic search of the PubMed, Embase, Cochrane Library, and Web of Science databases was performed from inception to December, 2021.

RESULTS

Five studies with 297 participants were included. There was no difference in the risk of persistent hyperthyroidism when radioactive iodine was used in conjunction with methimazole compared with when radioactive iodine was used alone (relative risk: 1.02, 95% confidence interval, CI: 0.62-1.66; P = 0.95, I2 = 0%). Subgroup analysis based on the duration between discontinuation of methimazole and the administration of radioactive iodine showed a lower risk of persistent hyperthyroidism when methimazole was discontinued within 7 days before radioactive iodine use, although this did not reach statistical significance (risk ratio: 0.85, CI: 0.28-2.58).

CONCLUSIONS

The use of methimazole before radioactive iodine administration was not associated with an increased risk of persistent hyperthyroidism. Concerns about medication toxicity and adverse effects should be considered when clinicians make decisions on combination therapies for the treatment of Graves' disease.

PROSPERO REGISTRATION

CRD42020150013, https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=150013.

Clinical characteristics of antithyroid drug-induced aplastic anemia cases over the past 30 years

OBJECTIVE

The authors aimed to investigate the clinical characteristics of antithyroid drug-induced aplastic anemia cases over the past 30 years.

METHODS

The data of patients with antithyroid drug-induced aplastic anemia were retrieved from PubMed and Wanfang Medical Network databases from 1992 to August 2022. The clinical characteristics, such as age distribution, gender tendency, common symptoms, blood cell count, bone marrow features, treatment strategy, and prognosis, were analyzed.

RESULTS

A total of 17 cases (male:female = 1:16) had been retrieved. Patients' age ranged from 16 to 74 years (median 50 years). Among them, 82.3% (14/17) of the patients were administered methimazole (MMI), and 78.6% of them had MMI ≥30 mg/day. In addition, 88.2% (15/17) of the patients had sore throat and fever, and 47.1% (8/17) of the patients had hemorrhagic symptoms. Aplastic anemia occurred within 6 months after initiation of the antithyroid therapy in 94.1% of the patients. Agranulocytosis (94.1%) was the most common and earliest blood cell change, and 47.1% of the patients experienced progressive platelet decline during the treatment process. The treatments include timely withdrawal of antithyroid drugs, broad-spectrum antibiotics, granulocyte colony-stimulating factor (G-CSF)/granulocyte-macrophage colony-stimulating factor (GM-CSF), glucocorticoids and other immunosuppressive agents, and supportive treatments such as erythrocyte transfusion and platelet transfusion. Moreover, 70.6% of the patients had complete or near-complete remission within 8 days to 6 weeks.

CONCLUSION

Aplastic anemia is a rare and serious adverse reaction of antithyroid drugs, which is more common in women. It usually occurs during early treatment with high-dose antithyroid drugs. Most patients have a good prognosis after timely drug ceasing and appropriate treatment.

Distinct Clinical Features of Post-COVID-19 Vaccination Early-onset Graves' Disease

CONTEXT

Several case reports of Graves' disease (GD) occurrence after COVID-19 vaccination that are possibly related to the autoimmune syndrome induced by adjuvants (ASIA) were published recently.

OBJECTIVE

The aim of our study was to evaluate possible distinctive features in the presentation and clinical course of patients with GD occurring early (within 4 weeks) after COVID-19 vaccination who attended our Endocrine Unit in 2021.

METHODS

Patients with a first episode of GD attending a tertiary endocrine center between January 1, 2021, and December 31, 2021, were included.

RESULTS

Sixty-four patients with a first episode of GD were seen in 2021: 20 (31.2%) of them had onset within 4 weeks following vaccine administration. Compared with the other 44 patients, the 20 patients with postvaccine early-onset (PoVEO) GD were older (median age 51 years vs 35 years, P = .003) and more likely to be male (40.0% vs 13.6%, P = .018). At diagnosis, the biochemical and immune profiles were similar between the 2 groups. However, at 3 months after starting methimazole, patients with PoVEO GD had significantly lower thyrotropin receptor antibody titer and were taking lower doses of methimazole than the other patients with GD. None in the PoVEO group had sustained free triiodothyronine elevation.

CONCLUSION

This relatively large series suggests that in 2021 PoVEO GD may be a new nosologic entity representing one-third of patients evaluated for new-onset GD in our center. Distinctive features included older age at onset, higher male prevalence, and a better initial biochemical and immunologic response to treatment. Further studies are warranted to clinically and biochemically differentiate these cases from sporadically occurring GD.

Efficacy and Safety of Long-Term Methimazole versus Radioactive Iodine in the Treatment of Toxic Multinodular Goiter

BACKGRUOUND

This study compared the degree of sustained control of hyperthyroidism in patients with toxic multinodular goiter (TMNG) treated with long-term methimazole (LT-MMI) or radioactive iodine (RAI).

METHODS

In this clinical trial, 130 untreated patients with TMNG were randomized to either LT-MMI or RAI treatment. Both groups were followed for 108 to 148 months, with median follow-up durations of 120 and 132 months in the LT-MMI and RAI groups, respectively. Both groups of patients were followed every 1 to 3 months in the first year and every 6 months thereafter.

RESULTS

After excluding patients in whom the treatment modality was changed and those who were lost to follow-up, 53 patients in the LT-MMI group and 54 in the RAI group completed the study. At the end of the study period, 50 (96%) and 25 (46%) patients were euthyroid, and two (4%) and 25 (46%) were hypothyroid in LT-MMI and RAI groups, respectively. In the RAI group, four (8%) patients had subclinical hyperthyroidism. The mean time to euthyroidism was 4.3±1.3 months in LT-MMI patients and 16.3± 15.0 months in RAI recipients (P<0.001). Patients treated with LT-MMI spent 95.8%±5.9% of the 12-year study period in a euthyroid state, whereas this proportion was 72.4%±14.8% in the RAI-treated patients (P<0.001). No major treatment-related adverse events were observed in either group.

CONCLUSION

In patients with TMNG, LT-MMI therapy is superior to RAI treatment, as shown by the earlier achievement of euthyroidism and the longer duration of sustained normal serum thyrotropin.

Approach to the Patient: Management and the Long-term Consequences of Graves' Disease in Children

In children, Graves' disease (GD) is the most common cause of hyperthyroidism. Most pediatric patients with GD will not go into lasting remission, even following many years of antidrug therapy. Thus, most pediatric patients will require radioactive iodine (RAI) or surgery. When antithyroid drugs are used, methimazole is the drug of choice. When methimazole is used in children, up to 20% will have minor adverse reactions and serious adverse events occur in up to 1%. RAI is an effective form of therapy when the thyroid size is less than 80 g. Because of concerns of whole-body radiation exposure, it is recommended that RAI be avoided in children under 5 years of age, and dosages less than 10 mCi be used between 5 and 10 years of age. Surgery is an effective treatment in children if performed by a high-volume thyroid surgeon. Because of the scarcity of high-volume pediatric thyroid surgeons, a multidisciplinary approach using pediatric surgeons and endocrine surgeons can be considered. Whereas there is a trend toward long-term antithyroid drug therapy in adults, for several reasons, this approach may not be practical for children. Determining the optimal treatment for the pediatric patient with GD, requires consideration of the risks and benefits relating to age and likelihood of remission.

[Methimazole Tablets-Induced Algospasm: Two Cases Report]

Here, we reported two cases with hyperthyroidism who complained of myalgia and muscle cramps during treatment with methimazole tablets (or Thyrozol, the brand name). One case experienced muscle cramps after taking Thyrozol for 6 months, and by this time the patient's thyroid function had returned to normal. In the other case, pain caused by muscular cramps began after the patient took Thyrozol for two weeks and the patient's thyroid function had not returned to normal yet at the time. In both cases, pain caused by muscle cramps appeared while the patients were taking Thyrozol. The myalgia persisted in spite of a reduction in the Thyrozol dose, but was significantly relieved with the discontinuation of Thyrozol. Myalgia and muscle cramps did not recur after the patients were switched to methimazole ointment. There was a strong temporal association between oral administration of Thyrozol and pain caused by muscle cramps, which may indicate that myalgia and muscle cramps are adverse reactions of Thyrozol. Looking into the relevant literature on the topic, we explored in this report the possible mechanisms of the onset of muscle cramps associated with Thyrozol, and compared the adverse reactions of two different formulations of methimazole, intending to provide more clinical experience for the treatment of hyperthyroidism and the management of rare adverse reactions related to antithyroid drugs.

Case report: hypoglycemia secondary to methimazole-induced insulin autoimmune syndrome in young Taiwanese woman with Graves' disease

RATIONALE

Hypoglycemia is an emergent condition with many causes, including underlying diabetes mellitus either with the use of insulin or oral anti-diabetic medications for glucose control, and organ (heart, hepatic, or renal) failure. Insulin autoimmune syndrome (IAS) can also cause hypoglycemia, however it is relatively difficult to diagnose as it is rare clinically. Although uncommon, IAS can be life threatening in patients with persistent hypoglycemia.

PATIENT CONCERN

We report the case of a 27-year-old female with underlying Graves' disease who was treated with methimazole (MTZ). After 6 weeks of treatment, she developed hypoglycemia symptoms accompanied by dizziness and cold sweating. We excluded underlying diabetes mellitus, the use of insulin or oral anti-diabetic medications, and organ failure.

DIAGNOSES

Laboratory data showed elevated insulin and C-peptide levels. Therefore, insulinoma and IAS were suspected. Abdominal computed tomography and magnetic resonance imaging ruled out insulinoma, and MTZ-induced IAS was finally diagnosed.

INTERVENTIONS AND OUTCOMES

The hypoglycemia symptoms resolved after MTZ was switched to propylthiouracil, confirming the diagnosis of IAS.

LESSONS

This case emphasizes the significance of life-threatening MTZ-induced IAS. IAS should be suspected in patients who develop spontaneous hypoglycemia, especially in those with underlying Graves' disease receiving MTZ who present with hyperinsulinism.

Antithyroid drug therapy in pregnancy and risk of congenital anomalies: Systematic review and meta-analysis

OBJECTIVES

The risk of congenital anomalies following in utero exposure to thionamide antithyroid drugs (ATDs) is unresolved. Observational studies are contradictory and existing meta-analyses predate and preclude more recent studies. We undertook an updated meta-analysis of congenital anomaly risk in women exposed to carbimazole or methimazole (CMZ/MMI), propylthiouracil (PTU), or untreated hyperthyroidism in pregnancy.

METHODS

We searched Medline, Embase, and the Cochrane database for articles published up till August 2021. We pooled separate crude and adjusted risk estimates using random effects models and subgroup analyses to address heterogeneity.

RESULTS

We identified 16 cohort studies comprising 5957, 15,785, and 15,666 exposures to CMZ/MMI, PTU, and untreated hyperthyroidism, respectively. Compared to nondisease controls, adjusted risk ratio (RR) and 95% confidence intervals (95% CIs) for congenital anomalies was increased for CMZ/MMI (RR, 1.28; 95% CI, 1.06-1.54) and PTU (RR, 1.16; 95% CI, 1.08-1.25). Crude risk for CMZ/MMI was increased relative to PTU (RR, 1.20; 95% CI, 1.01-1.43). Increased risk was also seen with exposure to both CMZ/MMI and PTU, that is, women who switched ATDs in pregnancy (RR, 1.51; 95% CI, 1.14-1.99). However, the timing of ATD switch was highly variable and included prepregnancy switches in some studies. The excess number of anomalies per 1000 live births was 17.2 for patients exposed to CMZ/MMI, 9.8, for PTU exposure, and 31.4 for exposure to both CMZ/MMI and PTU. Risk in the untreated group did not differ from control or ATD groups. The untreated group was however highly heterogeneous in terms of thyroid status. Subgroup analysis showed more positive associations in studies with >500 exposures and up to 1-year follow-up.

CONCLUSIONS

ATD therapy carries a small risk of congenital anomalies which is higher for CMZ/MMI than for PTU and does not appear to be reduced by switching ATDs in pregnancy. Due to key limitations in the available data, further studies will be required to clarify the risks associated with untreated hyperthyroidism and with switching ATDs in pregnancy.

Mathematical Modeling of Free Thyroxine Concentrations During Methimazole Treatment for Graves' Disease: Development and Validation of a Computer-Aided Thyroid Treatment Method

BACKGROUND

Methimazole (MMI) is the first-line treatment for patients with Graves' disease (GD). While there are empirical recommendations for initial MMI doses, there is no clear guidance for subsequent MMI dose titrations. We aimed to (a) develop a mathematical model capturing the dynamics of free thyroxine (FT4) during MMI treatment (b), validate this model by use of numerical simulation in comparison with real-life patient data (c), develop the software application Digital Thyroid (DigiThy) serving either as a practice tool for treating virtual patients or as a decision support system with dosing recommendations for MMI, and (d) validate this software framework by comparing the efficacy of its MMI dosing recommendations with that from clinical endocrinologists.

METHODS

Based on concepts of automatic control and by use of optimization techniques, we developed two first order ordinary differential equations for modeling FT4 dynamics during MMI treatment. Clinical data from patients with GD derived from the outpatient clinic of Endocrinology at the Medical University of Graz, Austria, were used to develop and validate this model. It was subsequently used to create the web-based software application DigiThy as a simulation environment for treating virtual patients and an autonomous computer-aided thyroid treatment (CATT) method providing MMI dosing recommendations.

RESULTS

Based on MMI doses, concentrations of FT4, thyroid-stimulating hormone (TSH), and TSH-receptor antibodies (TRAb), a mathematical model with 8 patient-specific constants was developed. Predicted FT4 concentrations were not significantly different compared to the available consecutively measured FT4 concentrations in 9 patients with GD (52 data pairs, p=0.607). Treatment success of MMI dosing recommendations in 41 virtually generated patients defined by achieved target FT4 concentrations preferably with low required MMI doses was similar between CATT and usual care. Statistically, CATT was significantly superior (p<0.001).

CONCLUSIONS

Our mathematical model produced valid FT4 predictions during MMI treatment in GD and provided the basis for the DigiThy application already serving as a training tool for treating virtual patients. Clinical trial data are required to evaluate whether DigiThy can be approved as a decision support system with automatically generated MMI dosing recommendations.

[T-lymphocytes phenotypic composition of peripheral blood in patients with Graves' disease undergoing conservative therapy with thiamazole]

BACKGROUND

Effective control of autoimmune inflammation in Graves' disease determines necessity to study the T helper (Th) and cytotoxic T-lymphocytes dysfunction, as well as the level of regulatory T-cells (Treg) activation in patients with Graves' disease on thyrostatic medication, which will clarify the immunomodulatory effects of long-term thiamazole treatment serve as targets for more specific therapies.

AIM

To study the phenotypic composition of T-lymphocytes in the peripheral blood of patients with Graves' disease to assess the direction of immune response depending on thimazole-induced euthyroidism duration.

MATERIALS AND METHODS

A single-center, cohort, continuous, open-label, controlled trial was conducted to assess the phenotypic composition of T-lymphocytes in peripheral blood in women with Graves' disease on long-term thiamazole treatment. The phenotypic composition of T-lymphocytes was determined by flow cytometry using direct immunofluorescence with conjugated FITC monoclonal antibodies depending on the duration of thimazole-induced euthyroidism of long-term thiamazole treatment.

RESULTS

The study included 135 women with Graves' disease, mean age 43.09±12.81 years, 120 (88.91%) with a relapse of the disease and 15 (11.09%) with newly diagnosed hyperthyroidism. An increase of activated CD3+CD4+CD25+ was found in patients with Graves' disease with a duration of thimazole-induced euthyroidism 5-8 months and 9-12 months, respectively, Me=0.94 (0.48-1.45), p=0.020) and Me=0.95 (0.41-1.80), p=0.025), in control group - Me=0.12 (0.03-0.68). Compared to the control an increase of CD4+CD25+CD127Low (Treg) was found in patients with a duration of thimazole-induced euthyroidism 5-8 and 9-12 months. The content of Treg in peripheral blood in Graves' disease patients with a duration of thimazole-induced euthyroidism more than 12 months decreases, but remains elevated relative to the control.

CONCLUSION

In patients with Graves' disease with a duration of thimazole-induced euthyroidism 5-8 months and 9-12 months the level of Treg has been increased. The increase of activated Th (CD3+CD4+CD25+) persists independently of thimazole-induced euthyroidism. In patients with Graves' disease with a duration of thimazole-induced euthyroidism for more than 12 months, there is a compensatory increase in regulatory T-lymphocyte, and the total number of T-helpers is restored to the control.

Rash and cholestatic liver injury caused by methimazole in a woman with Turner syndrome and Graves's disease: a case report and literature review

BACKGROUND

Rash and cholestatic liver injury caused by methimazole (MMI) in patients with Turner syndrome (TS) and Graves's disease (GD) are rarely reported, and there is a paucity of reports on the management of this condition. It is not clear whether propylthiouracil (PTU) can be used as a safe alternative in this case.

CASE PRESENTATION

A 37-year-old woman was admitted to our hospital with rash, severe pruritus and a change in urine colour after 2 months of GD treatment with MMI. Physical examination showed rash scattered over the limbs and torso, mild jaundice of the sclera and skin, short stature, facial moles, immature external genitals and diffuse thyroid gland enlargement. Liver function tests indicated an increase in total bilirubin, direct bilirubin, total bile acid, glutamic pyruvic transaminase, glutamic oxaloacetic transaminase and alkaline phosphatase. The level of sex hormones suggested female hypergonadotropic hypogonadism. The karyotype of peripheral blood was 46, X, i(X)(q10)/45, X. After excluding biliary obstruction and other common causes of liver injury, combined with rash and abnormal liver function following oral administration of MMI, the patient was diagnosed as having TS with GD and rash and cholestatic liver injury caused by MMI. MMI was immediately discontinued, and eleven days after treatment with antihistamine and hepatoprotective agents was initiated, the rash subsided, and liver function returned to nearly normal. Because the patient did not consent to administration of ¹³¹I or thyroid surgery, hyperthyroidism was successfully controlled with PTU. No adverse drug reactions were observed after switching to PTU.

CONCLUSIONS

While patients with TS and GD are undergoing treatment with MMI, their clinical manifestations, liver functions, and other routine blood test results should be closely monitored. When patients with TS and GD manifest adverse reactions to MMI such as rash and cholestatic liver injury, it is necessary to discontinue MMI and treat with antihistamine and hepatoprotective agents. After the rash subsides and liver function returns to nearly normal, PTU can effectively control hyperthyroidism without adverse drug reactions.

The efficiency and safety of methimazole and propylthiouracil in hyperthyroidism: A meta-analysis of randomized controlled trials

PURPOSE

The aim of this study was to evaluate the efficiency and safety of methimazole (MMI) and propylthiouracil (PTU) in the treatment of hyperthyroidism.

METHODS

Articles were searched through the PubMed, EMBASE, Cochrane Library, Web of Science, CNKI, Wanfang, and QVIP. The primary outcomes were clinical efficacy and thyroid hormone levels in MMI and PTU groups. The secondary outcomes were liver function indexes and adverse reactions in MMI and PTU groups. Results were expressed as weighted mean difference (WMD) or odds ratio (OR) with 95% confidence intervals (CIs). The Begg test was applied to assess the publication bias.

RESULTS

Totally, 16 randomized controlled trials were retained in this meta-analysis with 973 patients receiving MMI and 933 receiving PTU. The levels of triiodothyronine (T3) (WMD = -1.321, 95% CI: -2.271 to -0.372, P = .006), thyroxine (T4) (WMD = -37.311, 95% CI: -61.012 to -13.610, P = .002), Free T3 (FT3) (WMD = -1.388, 95% CI: -2.543 to -0.233, P = .019), Free T4 (FT4) (WMD = -3.613, 95% CI: -5.972 to -1.255, P = .003), and the risk of liver function damage (OR = 0.208, 95% CI: 0.146-0.296, P < .001) in the MMI group were lower than those in the PTU group. The thyroid-stimulating hormone level (WMD = 0.787, 95% CI: 0.380-1.194, P < .001) and the risk of hypothyroidism (OR = 2.738, 95% CI: 1.444-5.193, P = .002) were higher in the MMI group than those in the PTU group.

CONCLUSIONS

Although MMI might have higher risk of hypothyroidism than PTU, the efficacy of MMI may be better than PTU in patients with hyperthyroidism regarding reducing T3, T4, FT3, and FT4 levels, decreasing the risk of liver function damage and increasing the level of thyroid-stimulating hormone.

REGISTER NUMBER

osf.io/ds637 (https://osf.io/search/).

Antithyroid Drug Treatment in Graves' Disease

Graves' disease is associated with thyrotropin (TSH) receptor stimulating antibody, for which there is no therapeutic agent. This disease is currently treated through inhibition of thyroid hormone synthesis or destruction of the thyroid gland. Recurrence after antithyroid drug (ATD) treatment is common. Recent studies have shown that the longer is the duration of use of ATD, the higher is the remission rate. Considering the relationship between clinical outcomes and iodine intake, recurrence of Graves' disease is more common in iodine-deficient areas than in iodine-sufficient areas. Iodine restriction in an iodine-excessive area does not improve the effectiveness of ATD or increase remission rates. Recently, Danish and Korean nationwide studies noted significantly higher prevalence of birth defects in newborns exposed to ATD during the first trimester compared to that of those who did not have such exposure. The prevalence of birth defects was lowest when propylthiouracil (PTU) was used and decreased by only 0.15% when methimazole was changed to PTU in the first trimester. Therefore, it is best not to use ATD in the first trimester or to change to PTU before pregnancy.

Treatment of Subclinical Hyperthyroidism in the Elderly: Comparison of Radioiodine and Long-Term Methimazole Treatment

Background: This study aimed to compare the effectiveness and safety of radioiodine (RAI) and long-term methimazole (MMI) in the treatment of subclinical hyperthyroidism (SH) in the elderly. Methods: From 306 patients, aged ≥65 years, with SH, 83 patients with thyrotropin <0.1 mU/L entered the study. In this randomized parallel-group trial, 41 and 42 patients were randomized to either RAI or long-term MMI treatment, respectively. Results: In the RAI and MMI groups, 3 and 4 patients were excluded due to side effects, choosing other modes of treatment, and not returning for follow-up; 35 and 36 patients completed 60 months of follow-up, respectively. In the RAI group, 23 (66%) became hypothyroid, and 12 (34%) remained euthyroid 60 months after a fixed dose of 15 mCi RAI. In the MMI group, the starting dose was 10 mg daily and decreased to 4.9 ± 1.0, 4.3 ± 1.0, 4.4 ± 1.4, 4.3 ± 1.8, and 3.7 ± 1.3 mg after 1, 2, 3, 4, and 5 years of continuous MMI treatment, employing titration method. By the end of study, 34 (94%) patients were euthyroid and 2 patients with diffuse goiter developed spontaneous hypothyroidism with MMI treatment. Minor adverse events occurred in both groups in the first four months of treatment. No death or serious side effects were observed during 60 months of follow-up. Conclusions: Both RAI and long-term low-dose MMI therapies are effective and safe for treatment of SH in the elderly.

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

BACKGROUND

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.

METHODS

Fifty 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.

RESULTS

Of 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.

CONCLUSIONS

Long-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 REGISTRATION

IRCT201009224794N1, 2010-10-25. Retrospectively registered. https://www.irct.ir/trial/5143 .

An uncommon side effect of thiamazole treatment in Graves' disease

Thionamides (such as thiamazole/methimazole) are a common first line treatment for Graves' disease. Common side effects include rash, urticaria, and arthralgia. However, thionamide treatment has also been associated with a variety of auto-immune syndromes. Here, we describe a patient presenting with mild arthritis after starting thiamazole. Although severe presentation warrants acute withdrawal of the causative agent, our case suggests that milder forms can be successfully treated with anti-inflammatory drugs alone. Recognition of the syndrome is key to warrant timely and effective treatment.

Methimazole Treatment and Risk of Acute Pancreatitis: A Population-based Cohort Study

CONTEXT

A warning has been recently issued by the European Medicine Agency (EMA) regarding a potential increased risk of acute pancreatitis (AP) in methimazole (MMI) users.

OBJECTIVE

To investigate the association between MMI and the diagnosis of AP in a population-based study.

MATERIALS AND METHODS

A retrospective analysis of administrative health databases was conducted (2013-2018). Relevant data were obtained from: (1) inhabitants registry, (2) hospital discharge records (ICD-9-CM 577.0), and (3) drug claims registry (ATC H03BB02). We evaluated AP risk in MMI users in 18 months of treatment, stratifying results by trimester. Poisson regression was used to estimate the age- and sex-adjusted rate ratios (RR), and the relative 95% confidence intervals (CI), comparing rates of AP between MMI users and nonusers. The absolute risk of AP in MMI users was also calculated.

RESULTS

A total of 23 087 new users of MMI were identified. Among them, 61 hospitalizations occurred during the study period. An increase in AP risk was evident during the first 3 trimesters of therapy (RR 3.40 [95% CI: 2.12-5.48]; RR 2.40 [95% CI: 1.36-4.23]; RR 2.80 [95% CI: 1.66-4.73]), but disappeared thereafter. The AP absolute risk in MMI users during the first 18 months of treatment was less than 0.4% in all sex and age classes.

CONCLUSIONS

Our results support the EMA warning, suggesting an increased risk of AP associated with MMI use. However, such an increase seems limited to the first months of MMI treatment. Moreover, in absolute terms, the probability of AP is low among patients, well below 1%.

Association Between Thionamides and Acute Pancreatitis: A Case-Control Study

Background: Thionamides have been extensively used to treat patients with hyperthyroidism worldwide. Recent pharmacovigilance studies have revealed a safety signal between carbimazole or methimazole and pancreatitis. The associated risk remains unclear. Methods: We identified patients with newly diagnosed acute pancreatitis from 2000 to 2013 as the case group from the Taiwan Longitudinal Health Insurance Database 2000, which contains data from 1996 to 2013. Each patient with acute pancreatitis was matched for age, sex, comorbidities, and cancer with four controls through propensity score matching. A total of 52 patients without matched controls were excluded. Sensitivity analyses including the 52 excluded patients were performed using a matching ratio of 1:2. Odds ratios (ORs) along with 95% confidence intervals (CIs) for the association were estimated using multivariate logistic regression. Results: We included 9204 and 36,816 patients in the case and control groups, respectively. The proportions of patients who had used thionamides, carbimazole, methimazole, and propylthiouracil were similar in these two groups. In addition, the adjusted OR (CI) for the association of acute pancreatitis with thionamides was 1.03 (0.86-1.24), with carbimazole it was 0.90 (0.63-1.30), with methimazole it was 1.05 (0.84-1.31), and with propylthiouracil it was 1.00 (0.74-1.34). The sensitivity analysis results were unchanged. Conclusions: We were unable to demonstrate an association between acute pancreatitis and usage of thionamides.

Concomitant Gallbladder Agenesis with Methimazole Embryopathy

BACKGROUND Methimazole embryopathy is caused by maternal methimazole intake during early pregnancy. It causes fetal malformations such as choanal atresia, esophageal atresia, aplasia cutis, omphalomesenteric duct remnants, urachal remnants, and omphalocele. Gallbladder agenesis is sometimes complicated with other malformations, but there have been no reports of gallbladder agenesis due to methimazole or concomitant methimazole embryopathy with gallbladder agenesis. CASE REPORT The mother of a male neonate had taken methimazole for hyperthyroidism until pregnancy was recognized at 7 weeks of gestation. Ultrasonography at 12 weeks and 4 days of gestation showed the fetus had a cystic lesion in the umbilical region. The child was born at the gestational age of 38 weeks and 5 days. At birth there was omphalocele, omphalomesenteric fistula, and a scalp defect, and the child was diagnosed with methimazole embryopathy. Ultrasonography could not identify the gallbladder. Emergency surgery was performed for omphalocele with omphalomesenteric fistula on day 0. The intestine, including the omphalomesenteric fistula, was resected. Postoperative blood testing revealed hypothyroidism, so the patient was administered levothyroxine. Although MRI did not detect the gallbladder, it showed dilatation of the biliary duct. Hypothyroidism was well controlled by levothyroxine, so the patient was discharged with outpatient follow-up for the gallbladder agenesis. Six months later, the patient is asymptomatic. CONCLUSIONS Concomitant gallbladder agenesis with methimazole embryopathy has not been previously reported. In the case of a dilated common bile duct, even when asymptomatic in the neonatal period, gallbladder agenesis demands long-term follow-up because of possible manifestation of choledocholithiasis or biliary malignant tumors.

Clinical experience of treating Graves' hyperthyroidism complicated with malignancy-The possible role of potassium iodide for avoiding the risk of thionamide-associated neutropenia

The treatment of Graves' hyperthyroidism (GD) complicated with malignancy is challenging, as anti-thyroid thionamide drugs (ATDs) and anti-cancer chemotherapy are both associated with a risk of neutropenia. Treatment with conventional ATDs, radioactive iodine (RAI) or potassium iodide (KI) was attempted in 8 patients with malignancy (34-80 years of age; 2 males and 6 females) in whom GD had been fortuitously diagnosed during a detailed systematic examination. Three patients requiring surgery were initially treated conventionally with methylmercaptoimidazole (MMI), MMI and KI or RAI (group A; one patient each). The patients became euthyroid on days 17-31 and underwent surgery on days 25-47. RAI therapy was administered to one patient after surgery. The patients were then treated with KI during chemotherapy. Five other patients who did not require surgery were initially treated with 100 mg KI monotherapy (group B). The serum free T₄ level declined immediately in all of these patients, and they became euthyroid on days 7-18, remaining almost entirely euthyroid for more than 120 days. Anti-cancer chemotherapy was successfully completed for three of the patients while taking KI, despite the patients experiencing repeated episodes of anti-cancer chemotherapy-induced neutropenia. Our present findings suggest that, in patients with GD and malignancy, MMI + KI or RAI may be required if immediate surgery is scheduled, but KI monotherapy may be worth trying, if anti-cancer chemotherapy is scheduled, thus avoiding the possibility of thionamide-induced neutropenia.

Informatics investigations into anti-thyroid drug induced agranulocytosis associated with multiple HLA-B alleles

INTRODUCTION

Adverse drug reactions have been linked with HLA alleles in different studies. These HLA proteins play an essential role in the adaptive immune response for the presentation of self and non-self peptides. Anti-thyroid drugs methimazole and propylthiouracil have been associated with drug induced agranulocytosis (severe lower white blood cell count) in patients with B*27:05, B*38:02 and DRB1*08:03 alleles in different populations: Taiwanese, Vietnamese, Han Chinese and Caucasian.

METHODS

In this study, informatics methods were used to investigate if any sequence or structural similarities exist between the two associated HLA-B alleles, compared with a set of "control" alleles assumed not be associated, which could help explain the molecular basis of the adverse drug reaction. We demonstrated using MHC Motif Viewer and MHCcluster that the two alleles do not have a propensity to bind similar peptides, and thus at a gross level the structure of the antigen presentation region of the two alleles are not similar. We also performed multiple sequence alignment to identify polymorphisms shared by the risk but not by the control alleles and molecular docking to compare the predicted binding poses of the drug-allele combinations.

RESULTS

Two residues, Cys67 and Thr80, were identified from the multiple sequence alignments to be unique to these risk alleles alone. The molecular docking showed the poses of the risk alleles to favour the F-pocket of the peptide binding groove, close to the Thr80 residue, with the control alleles generally favouring a different pocket. The data are thus suggestive that Thr80 may be a critical residue in HLA-mediated anti-thyroid drug induced agranulocytosis, and thus can guide future research and risk assessment.

Successful Treatment of Amiodarone-induced Thyrotoxicosis Type 1 in Combination with Methimazole and Potassium Iodide in a Patient with Hashimoto's Thyroiditis

A patient with underlying Hashimoto's thyroiditis developed amiodarone-induced thyrotoxicosis type 1 that was successfully treated using methimazole in combination with potassium iodide. A 35-year-old woman admitted for perinatal care of twin-to-twin transfusion syndrome was given amiodarone for 7 days for paroxysmal ventricular contraction following pulseless ventricular tachycardia 1 day after delivery. She developed thyrotoxicosis one month after the discontinuation of amiodarone therapy and was negative for thyroid-stimulating hormone receptor antibody. An increased peak velocity of the superior thyroid artery suggested amiodarone-induced thyrotoxicosis type 1. Her thyroid function recovered after combination therapy with methimazole and potassium iodide.

Treatment of Graves' hyperthyroidism with thionamides: a position paper on indications and safety in pregnancy

CONTEXT

Graves' disease affects 3% of women and 0.5% of men in the general population. The first line treatment of Graves' hyperthyroidism is based on the administration of antithyroid drugs (ATD), propylthiouracil (PTU), methimazole (MMI) and carbimazole. A recent warning from the Italian Drug Agency (Agenzia Italiana del Farmaco AIFA) reported the risk of MMI-induced acute pancreatitis. In addition, AIFA highlighted the possible association of MMI treatment during the first trimester of pregnancy with congenital malformations, thus recommending the use of effective contraceptive methods in women of childbearing age treated with MMI.

METHODS AND RESULTS

Revision of literature reported less than ten cases of the alleged MMI pancreatitis, allowing the inclusion of MMI in class III drug regarding the relative risk for drug-induced pancreatitis. Data available on the effect of hyperthyroidism per se on the risk of fetal malformations, although scanty, are sufficient to recommend treatment with ATD of the hyperthyroid pregnant woman. Case reports and population studies either suggesting or not suggesting MMI-induced fetal malformations do not allow unquestionable conclusions on this matter.

CONCLUSIONS

This consensus by experts from Italian Endocrine and Gynecologic Scientific Societies has edited recommendations derived form the available data and published guidelines of International Scientific Societies.

Myopathy after rapid correction of hyperthyroidism: A case report and review of literature

RATIONALE

Myalgia and elevated creatine kinase (CK) have been reported during the treatment of hyperthyroid patients. The causes of these symptoms are usually considered to be treatments of antithyroid drugs (ATDs), thyroidectomy or radio-iodine (131-I). However, the underlying cause may be the rapid correction of thyrotoxicosis (or relative hypothyroidism), which was usually neglected in clinical practice.

PATIENT CONCERNS

This report describes a case of a 25-year-old female with typical symptoms and laboratory test results of Grave hyperthyroidism. The patient complained about fatigue and myalgia 7 weeks after receiving methimazole (MMI) treatment. Blood tests showed dramatically elevated serum CK level, although free triiodothyronine (FT3) and free thyroxine (FT4) level had returned to the normal reference range. MMI was; therefore, discontinued and the patient's muscular symptoms disappeared quickly with the normalization of CK level and the relapse of hyperthyroidism. Later she received 131-I treatment and suffered similar muscular symptoms when FT3 and FT4 decreased to the normal range. This time, her symptoms were quickly relieved by levothyroxine (L-T4) replacement treatment.

DIAGNOSES

Myopathy induced by rapid correction of hyperthyroidism (or relative hypothyroidism).

INTERVENTIONS

MMI was discontinued after the patient's first episode of muscular symptoms. And for her second episode of muscular injury after 131-I treatment, we initiated L-T4 supplementation.

OUTCOMES

For the 2 episodes of muscular injury after ATDs or 131-I treatment, both of the interventions mentioned above brought a rapid relief of symptoms accompanied with normalization of CK level and restoration of thyroid hormone level.

LESSONS

Myopathy can be caused by a rapid reduction of thyroid hormone during the treatment of hyperthyroidism. This relative hypothyroidism syndrome should be considered if patients make complaints about fatigue and myalgia, even when thyroid hormone level is within the normal range during the antithyroid treatments. Serum CK level and thyroid function should be closely monitored post antithyroid treatments. Reduction of ATD dosage or replacement of thyroid hormone is suggested to relieve muscular symptoms.

Analysis of Antithyroid Drug-Induced Severe Liver Injury in 18,558 Newly Diagnosed Patients with Graves' Disease in Japan

Background: The prevalence of antithyroid drug (ATD)-related drug-induced liver injury (DILI) has been reported to vary among patients in several countries. The purpose of this study was to summarize the prevalence of liver injury induced by ATD and to determine the actual prevalence of severe liver injury. Methods: The medical records of 18,558 patients who were newly diagnosed with Graves' disease between January 2005 and December 2016 were retrospectively reviewed. Severe DILI was defined as alanine aminotransferase (ALT) 8 times higher than the upper limit of normal (ULN) or total bilirubin (T-bil) 3 times higher than the ULN. The most severe DILI was defined as ALT higher than 20 times the ULN or T-bil higher than 10 times the ULN. Results: A total of 461 subjects (470 cases) were analyzed, and they consisted of 10 males and 451 females, with a median age of 37 years (range 10-82 years). Nine of 461 patients had severe DILI with both drugs. The total prevalence of severe DILI in this study was 2.5%, and the prevalence of DILI by drug was 1.4% with metimazole (MMI) (n = 198) and 6.3% with propylthiouracil (PTU) (n = 272) (p < 0.001). The prevalence of the most severe ATD-related DILI was 0.22% (n = 40), and the prevalence for each drug was 0.08% with MMI (n = 11) and 0.68% with PTU (n = 29). The median time to DILI development was 30 days (range 7-314 days), and all patients recovered from DILI, with no fatalities. The prevalence of MMI-related DILI was significantly age dependent (p < 0.001). Conclusions: Though there were no fatalities in this study, the prevalence of PTU-related severe DILI was significantly higher than that of MMI-related severe DILI.

Increased Remission Rates After Long-Term Methimazole Therapy in Patients with Graves' Disease: Results of a Randomized Clinical Trial

Background: Studies differ regarding whether, compared with courses of conventional duration, longer-term antithyroid drug treatment increases frequency of remission in patients with Graves' hyperthyroidism. We prospectively conducted a randomized, parallel-group study comparing relapse rates in patients receiving longer-term versus conventional-length methimazole therapy. We also sought variables associated with relapse following the latter. Methods: We enrolled 302 consecutive patients with untreated first episodes of Graves' hyperthyroidism. After 18-24 months of methimazole, 258 patients (85.4%) were randomized to an additional 36-102-month courses ("long-term group": n = 130; scheduled total time on methimazole: 60-120 months) or discontinuation of methimazole ("conventional group": n = 128). Patients were followed 48 months postmethimazole cessation. We performed Cox proportional hazards modeling to identify factors associated with relapse after conventional courses. Results: Methimazole was given for 95 ± 22 months in long-term patients and 19 ± 3 months in the conventional group. Fourteen patients experienced cutaneous reactions and 2 liver enzyme elevations during the first 18 months of treatment; no further methimazole-related reactions were observed despite therapy for up to another 118 months. Hyperthyroidism recurred within 48 months postmethimazole withdrawal in 15% (18/119) of long-term patients versus 53% (65/123) of conventional group patients. In the conventional group, older age, higher triiodothyronine or thyrotropin receptor antibody concentrations, lower thyrotropin concentration, or possession of the rs1879877 CD28 polymorphism or the DQB1-05 HLA polymorphism were independently associated with relapse. Conclusion: Administration of low-dose methimazole for a total of 60-120 months safely and effectively treats Graves' hyperthyroidism, with much higher remission rates than those attained by using conventional 18-24-month courses.

Treatment of Toxic Multinodular Goiter: Comparison of Radioiodine and Long-Term Methimazole Treatment

Background: This study aimed to compare the effectiveness and safety of long-term methimazole (MMI) and radioiodine (RAI) in the treatment of toxic multinodular goiter (TMNG). Methods: In this randomized, parallel-group trial, 130 consecutive and untreated patients with TMNG, aged <60 years, were enrolled and randomized to either long-term MMI or RAI treatment. Both groups of patients were followed for 60-100 months, with median durations of 72 and 84 months in the MMI and RAI groups, respectively. Results: In the MMI and RAI groups, 12 and 11 patients, respectively, were excluded because of side effects, choosing other modes of treatment and not returning for follow-up; 53 and 54 patients, respectively, completed the study for 60-100 months. In the MMI group, two patients (3.8%) experienced subclinical hypothyroidism, and 51 (96.2%) remained euthyroid until the end of study. The dosage of MMI to maintain euthyroidism was 6.3 ± 2.0, 4.5 ± 0.9, and 4.1 ± 1.0 mg daily during the first, third, and fifth years of continuous MMI treatment. One patient had elevated liver enzymes, and three developed skin reactions during the first three months, but no adverse effects from MMI occurred from 4 to 100 months of therapy. In the RAI group, 22 (41%) became hypothyroid, 12 (22%) had persistence or recurrence of hyperthyroidism, and 20 (37%) became euthyroid after 16.7 ± 2.7 mCi ¹³¹I. Conclusion: Long-term, low-dose MMI treatment for 60-100 months is a safe and effective method for treatment of TMNG, and is not inferior to RAI treatment.

Increased Risk of Antithyroid Drug Agranulocytosis Associated with Amiodarone-Induced Thyrotoxicosis: A Population-Based Cohort Study

BACKGROUND

Agranulocytosis occurs in 0.2-0.5% of patients treated with the antithyroid drugs (ATDs) methimazole and propylthiouracil. The objectives of this study were to evaluate the risk of ATD-related agranulocytosis in patients with amiodarone-induced thyrotoxicosis (AIT), and to compare it with the agranulocytosis risk in patients with thyrotoxicosis due to other etiologies treated with ATDs.

METHODS

This was a retrospective cohort study. Participants were 14,781 adult patients with thyrotoxicosis, newly treated with an ATD between January 1, 2002, and December 31, 2015. Among them were 593 patients treated by ATDs due to AIT. The main outcome measures were incidence rates and crude and adjusted hazard ratios using univariate and multivariable Cox regression models for ATD-related agranulocytosis within one year of treatment initiation, in association with AIT.

RESULTS

Agranulocytosis occurred in 28 (0.19%) of patients newly treated with methimazole or propylthiouracil during the first year of follow-up. Of these 28 patients, 8/593 (1.35%) were AIT patients and 20/14,188 (0.14%) were thyrotoxic patients that was not AIT related (p < 0.001). Incidence rates were 22 (9.47-43.36) cases/1000 person-years of follow-up in AIT, and 1.79 (1.09-2.76)/1000 person-years of follow-up in non-AIT thyrotoxicosis (p < 0.0001). In univariate Cox regression analysis, risk for ATD agranulocytosis associated with AIT was 9.71 (4.28-22.05) compared to the risk in non-AIT thyrotoxicosis. In a multivariable model, adjusting for age, sex, body mass index, smoking history, year of cohort entry, diabetes mellitus, hypertension, renal failure, beta blockers, calcium channel blockers, anti-aggregants, and dose of ATDs, the risk associated with AIT was 5.70 (2.14-15.21). In a model adjusted for a propensity score to receive amiodarone, risk for ATD agranulocytosis associated with AIT was 6.32 (1.22-32.70).

CONCLUSIONS

ATD use is associated with a higher risk for agranulocytosis in patients with AIT.

Insulin autoimmune syndrome: Three case reports

RATIONALE

Insulin autoimmune syndrome (IAS) is a rare endocrine disease characterized by repeated fasting hypoglycemia or episodes of hypoglycemia late after meals, elevated serum insulin, and positivity for insulin autoantibody (IAA) or insulin receptor antibody (IRA). We summarize the clinical manifestations and treatment experiences of 3 patients with IAS.

PATIENT CONCERNS

One patient with >20-year history of type 2 diabetes mellitus had irregular episodes of hypoglycemia 2 years of after treatment with insulin. Another patient with a 6-year history of type 2 diabetes mellitus presented irregular episodes of hypoglycemia after 6 months of treatment with insulin. One patient with a history of Graves' disease showed hypoglycemia after administration of thiamazole.

DIAGNOSIS

Serum islet cell antibody (ICA) and glutamic acid decarboxylase antibody (GADA) were negative, while antibody insulin autoantibodies were positive in all the 3 patients. Two patients demonstrated diabetes mellitus after an oral glucose tolerance test, while one had normal glucose tolerance. Furthermore, serum insulin levels significantly elevated and did not matched C peptide levels. No abnormalities were found on enhanced MRI of the pancreas, and all 3 patients were clinically diagnosed with IAS.

INTERVENTIONS

In case one, insulin aspart 30 injection was withdrawn after admission. In addition, the patient was prescribed sublingual acarbose 3 times daily. Two weeks after admission, prednisone acetate was administered orally once daily at night. In case 2, insulin aspart 30 injection was withdrawn after admission, the patient was prescribed sublingual acarbose 3 times daily with a meal. Five days after admission, oral prednisone acetate was administered once daily at night. In case 3, oral propylthiouracil was prescribed and thiamazole withdrawn after admission, and the patient consumed an extra meal before sleeping.

OUTCOMES

At the 3-month follow-up visit, the hypoglycemic episodes had disappeared, serum insulin levels were significantly decreased, and insulin antibody (IA) levels were no longer detectable in all 3 patients.

LESSONS

For those patients with high-insulin hypoglycemia, IAA should be evaluated if serum insulin concentrations are inconsistent with C peptide levels. Therapeutically, a lower dose of glucocorticoids with more appropriate medication timing can be used to achieve good results.

FROSTED BRANCH ANGIITIS IN METHIMAZOLE-INDUCED ANTINEUTROPHIL CYTOPLASMIC ANTIBODY-POSITIVE VASCULITIS

PURPOSE

To describe an unusual case of frosted branch angiitis that developed in a patient with acute onset systemic vasculitis possibly triggered by the antithyroid medication methimazole.

METHODS

We conducted a thorough review of the medical records of a 16-year-old female patient who presented with frosted branch angiitis. During the initial hospital admission, the patient underwent an extensive systemic workup to determine the etiology of her disease and ophthalmologic testing including fundus photographs and fluorescein angiography.

RESULTS

Our patient presented with a unilateral acute onset loss of vision, whose fundus examination revealed the pathognomonic features of frosted branch angiitis. Extensive systemic workup revealed an antineutrophilic cytoplasmic antibody-positive vasculitis, possibly triggered by methimazole.

CONCLUSION

This case is the first reported frosted branch angiitis associated with a drug-induced antineutrophilic cytoplasmic antibody-positive vasculitis triggered by methimazole.

Clinical efficacy of Yingliu mixture combined with metimazole for treating diffuse goitre with hyperthyroidism and its impact on related cytokines

CONTEXT

Yingliu mixture was developed in 1990s by Affiliated Longhua Hospital of Shanghai University of Traditional Chinese Medicine, for treating diffuse goitre with hyperthyroidism (Graves' disease, GD). Former studies have shown Yingliu mixture combined with methimazole (Y-M) can effectively improve thyroid function and decrease thyrotropin-receptor antibody level. Furthermore, we researched its impact on related cytokines to prove that Y-M improve patients' immunity status.

OBJECTIVE

To observe the clinical efficacy of Y-M for treating GD.

METHODS

A total of 120 GD patients were randomly divided into two groups, the treatment and the control groups (n = 60). The treatment group's patients were treated with Y-M. The control group's patients were treated with methimazole alone. Yingliu mixture was orally administered, 25 mL three times daily. Methimazole was administered at 5-25 mg/day. After 12 weeks of the treatment, the cytokines, antibodies related to thyroid function, and Chinese medical syndromes were evaluated.

RESULTS

After the treatment, the free triiodothyronine and thyroxine levels in both groups decreased. The thyroid-stimulating hormone level increased in the treatment group. The thyrotropin-receptor antibody levels and TNF-α levels decreased in both groups. In the control group, IL-6 and IFN-γ levels were lower than that before the treatment. In the treatment group, CD4⁺ and CD25⁺ levels were higher than pretreatment levels, but IL-10 levels were reduced.

CLINICAL SYMPTOMS

the total CMS scores for both groups decreased.

CONCLUSIONS

The Y-M combination can improve thyroid function, and decrease autoantibodies, cytokines, and clinical symptoms, so its efficacy may surpass that of methimazole alone.

A rare case of methimazole-induced cholestatic jaundice in an elderly man of Asian ethnicity with hyperthyroidism: A case report

BACKGROUND

Methimazole is an antithyroid drug that is widely used for the treatment of hyperthyroidism. As an inhibitor of the enzyme thyroperoxidase, methimazole is generally well-tolerated. However, there have been increasing reports of methimazole-induced liver damage, although this effect of methimazole has been limited by the absence of objective diagnosis of the liver condition or the inappropriate use of the Naranjo scale. We present the case of an elderly man with hyperthyroidism, gastritis, and epilepsy who developed liver damage after administration of multiple drugs.

KEY POINTS FROM THE CASE

Considering the low sensitivity of the Naranjo scale in detecting rare reactions associated with liver damage, we used the Roussel-Uclaf Causality Assessment Method scale, with a finding of cholestatic jaundice hepatitis induced by methimazole. The patient's liver enzyme levels improved after discontinuation of methimazole.

MAIN LESSONS LEARNED

Our case underlines the possible hepatoxicity associated with the use of methimazole. A review of the literature confirmed a selective hepatoxicity risk in individuals of Asian ethnicity, which has not been identified in Caucasian or Black populations. Physicians should be aware of the risk of hepatoxicity when prescribing oral methimazole to patients of Asian ethnicity.

Insulin autoimmune syndrome in a pregnant female: A rare case report

RATIONALE

Insulin autoimmune syndrome (IAS) is an uncommon disorder characterized by hyperinsulinemic hypoglycemia related to insulin-binding autoantibodies. To the best of our knowledge, we report the first case of a pregnant female with IAS.

PATIENT CONCERNS

The 26-year-old patient with Graves disease and 10 weeks pregnant developed IAS after approximately 6 months treatment with methimazole. The patient exhibited recurrent spontaneous hypoglycemia.

DIAGNOSES

On evaluation, laboratory findings detected both high fasting insulin (>1000 mIU/L) and insulin autoantibodies. An oral glucose tolerance test showed elevated insulin concentrations with disproportionately elevated C-peptide levels. The imaging study showed nomasslesionsinthepancreas,and the patient was clinically diagnosed with IAS.

INTERVENTIONS

The patient had an abortion, discontinued methimazole and switched to oral prednisone (30 mg once daily) and propylth- iouracil (100 mg 3 times daily) for 3 months.

OUTCOMES

At the 3-month follow-up visit, hypoglycemic episodes had disappeared and insulin antibody levels were no longer detectable.

LESSONS

We have described this case and reviewed the relevant literature concerning diagnosis and treatment of IAS. Importantly, this case indicates that clinicians should view pregnancy as another factor of hypoglycemia in IAS.

Risk of embryopathies with use of antithyroidal medications

PURPOSE OF REVIEW

Hyperthyroidism in pregnant women should be adequately treated to prevent maternal and fetal complications. The treatment of choice in pregnancy is antithyroidal medications (ATDs). The risk of embryopathies associated with the use of Methimazole (MMI) and Propylthiouracil (PTU) in early pregnancy is a matter of clinical attention and concern. This review describes current evidence and how scientific findings are reflected in current clinical guidelines.

RECENT FINDINGS

Embryopathies after the use of ATDs were previously mainly described in case reports and considered rare. Recent large observational studies, including nonexposed control groups, have quantified an increased risk of embryopathies associated with use of ATDs during pregnancy. Findings suggest a risk of embryopathies with the use of both MMI and PTU, but the pattern of embryopathies differs, and embryopathies with the use of PTU appear less severe.

SUMMARY

Current guidelines highlight the need for clinical attention on the use of ATDs in early pregnancy. Patients managed on ATDs for the treatment of hyperthyroidism should be counseled to report a pregnancy as early as possible. PTU is the recommended treatment in early pregnancy, but if the risk of relapse or worsening of hyperthyroidism is considered low, it is suggested that ATD treatment can be withdrawn followed by frequent monitoring of thyroid function.

Methimazole-induced liver injury overshadowed by methylprednisolone pulse therapy: Case report

RATIONALE

Treatment choices are limited, when deciding how to manage thyrotoxicosis and moderate to severe Graves ophthalmopathy (GO) with suspected optic nerve damage in patients with elevated liver transaminase levels. The situation become even more complicated, if methimazole induced hepatotoxicity is suspected and intravenous methylprednisolone is co-administrated.

PATIENT CONCERNS

A 74-year-old woman presented with spontaneous retro-bulbar pain, eyelid swelling and inconstant diplopia.

DIAGNOSES

Thyrotoxicosis and severe GO with suspected optic nerve damage and drug induced liver injury (DILI).

INTERVENTIONS

Intravenous methylprednisolone pulse therapy was administered to treat GO and methimazole was continued for thyrotoxicosis. Dose of methimazole was reduced after exclusion of concurrent infection and active liver disease.

OUTCOMES

The GO symptoms (eyelid swelling, sight loss, proptosis, retro-bulbar pain, diplopia) markedly decreased after the treatment course. Liver transaminases spontaneously returned to normal ranges and remained normal during the next 12 months until the Graves' disease until the treatment was completed.

LESSONS

1. The interaction of methimazole and methylprednisolone may result in DILI. 2. In a patient without concomitant liver diseases MP can be continued if the methimazole dose is reduced if no other treatment options are available.