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.

Filgrastim Use in the Treatment of Azathioprine-Induced Myelosuppression Toxicity After Prescription Error in the Feline.

Only one report on the successful use of filgrastim (granulocyte colony-stimulating factor) in cats for severe neutropenia following azathioprine toxicity exists. Here, we report on a case in which a cat was prescribed methimazole but the medication was filled incorrectly with azathioprine tablets and the prescription label indicated a methimazole dosing regimen that was administered for three days before recognition of the error. On presentation, the cat's physical examinations were consistent with previous examinations before ingestion of azathioprine. A complete blood cell count revealed neutropenia and leukopenia. The cat later developed hyporexia, dehydration, and vomiting. Treatment included antinausea and appetite stimulant medications, filgrastim, and antibiotics. Filgrastim given as subcutaneous injections over the course of treatment increased neutrophil cell counts after suppression. The cat made a full recovery after responding to the treatment protocol. Based on the perceived response to filgrastim in this single feline case report, its use can be considered for the treatment of azathioprine-induced neutropenia in cats.

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.

Risk of recurrence at the time of withdrawal of short- or long-term methimazole therapy in patients with Graves' hyperthyroidism: a randomized trial and a risk-scoring model.

PURPOSE: In Graves' disease, administration of low-dose methimazole for more than 60 months induces higher remission rates compared with the conventional duration of 12-18 months. However, the risk of recurrence and its predictors beyond 48 months of drug withdrawal are not known. The aims of this study were to determine the risk of recurrence during 84 months after withdrawal of short- or long-term methimazole therapy and a risk stratification for recurrence of hyperthyroidism. METHODS: A total of 258 patients were treated with methimazole for a median of 18 months and randomized to discontinuation of the drug(conventional short-term group; n = 128) or continuation of the treatment up to 60-120 months(long-term group; n = 130). Patients were followed for 84 months after methimazole withdrawal. Cox proportional hazards modeling was performed to identify factors associated with relapse and develop a risk-scoring model at the time of discontinuing the treatment. RESULTS: Hyperthyroidism recurred in 67 of 120(56%) of conventionally-treated patients versus 20 of 118(17%) of those who received long-term methimazole treatment, p < 0.001. Age, sex, goiter grade, triiodothyronine, thyrotropin, and thyrotropin receptor antibodies were significant predictors of recurrence in both "conventional" and "long-term" groups but free thyroxine just in the "long-term" group. The risk-scoring model had a good discrimination power (optimism corrected c-index = 0.78,95%CI = 0.73-0.82) with a range of 0-14 and sensitivity of 86% and specificity of 62% at the risk-score of eight. CONCLUSION: A relapse-free state was achieved in 83% of patients with Graves' hyperthyroidism 84 months after cessation of long-term methimazole treatment which could be predicted by some significant predictors in a simple risk-scoring system.

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.

[Leukocytoclastic vasculitis as an adverse effect of propylthiouracil. A case report]. / Vasculitis leucocitoclástica como efecto adverso del propiltiouracilo. Reporte de un caso.

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.

ANTECEDENTES: La causa más frecuente de hipertiroidismo es la enfermedad de Graves. El propiltiouracilo es uno de los medicamentos más prescritos para esta enfermedad. Uno de los efectos adversos dermatológicos del propiltiouracilo es la vasculitis leucocitoclástica. REPORTE DE CASO: Paciente femenina de 18 años, alérgica al metamizol, con vasculitis asociada a ANCAs, con características de vasculitis leucocitoclástica provocada por el consumo de propiltiouracilo. No se observó afectación sistémica. Dos meses después de suspender el propiltiouracilo desaparecieron casi por completo las lesiones en la piel. CONCLUSIONES: La vasculitis leucocitoclástica debe considerarse en el espectro de complicaciones provocadas por el consumo de propiltiouracilo. Las lesiones pueden manifestarse con el paso del tiempo, desde unas semanas hasta años después de consumir el fármaco. Cuando no existe afectación sistémica, la suspensión del propiltiouracilo es suficiente para detener la enfermedad.

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.

Safety and efficacy of prophylactic treatment for hyperthyroidism induced by iodinated contrast media in a high-risk population.

Introduction: The use of iodinated contrast media (ICM) can lead to thyrotoxicosis, especially in patients with risk factors, such as Graves' disease, multinodular goiter, older age, and iodine deficiency. Although hyperthyroidism may have clinically relevant effects, whether high-risk patients should receive prophylactic treatment before they are administered ICM is still debated. Aim of the study: We aimed to demonstrate the safety and efficacy of prophylactic treatment with sodium perchlorate and/or methimazole to prevent ICM-induced hyperthyroidism (ICMIH) in a population of high-risk cardiac patients. We ran a cost analysis to ascertain the most cost-effective prophylactic treatment protocol. We also aimed to identify possible risk factors for the onset of ICMIH. Materials and methods: We performed a longitudinal retrospective study on 61 patients admitted to a tertiary-level cardiology unit for diagnostic and/or therapeutic ICM-procedures. We included patients with available records of thyroid function tests performed before and after ICM were administered, who were at high risk of developing ICMIH. Patients were given one of two different prophylactic treatments (methimazole alone or both methimazole and sodium perchlorate) or no prophylactic treatment. The difference between their thyroid function at the baseline and 11-30 days after the ICM-related procedure was considered the principal endpoint. Results: Twenty-three (38%) of the 61 patients were given a prophylactic treatment. Thyroid function deteriorated after the administration of ICM in 9/61 patients (15%). These cases were associated with higher plasma creatinine levels at admission, higher baseline TSH levels, lower baseline FT4 levels, and no use of prophylactic treatment. The type of prophylaxis provided did not influence any onset of ICMIH. A cost-benefit analysis showed that prophylactic treatment with methimazole alone was less costly per person than the combination protocol. On multivariate analysis, only the use of a prophylactic treatment was independently associated with a reduction in the risk of ICMIH. Patients not given any prophylactic treatment had a nearly five-fold higher relative risk of developing ICMIH. Conclusion: Prophylactic treatment can prevent the onset of ICMIH in high-risk populations administered ICM. Prophylaxis is safe and effective in this setting, especially in cardiopathic patients. Prophylaxis with methimazole alone seems to be the most cost-effective option.

A Disproportionality Analysis of the Adverse Effect Profiles of Methimazole and Propylthiouracil in Patients with Hyperthyroidism Using the Japanese Adverse Drug Event Report Database.

Background: Antithyroid drugs (ATDs) are frequently used to achieve euthyroidism in patients with hyperthyroidism. ATDs cause characteristic common and rare adverse events; however, comprehensive comparisons between methimazole (MMI) and propylthiouracil (PTU) in terms of adverse events are limited. Methods: In this study, we thoroughly explored adverse events in association with MMI and PTU use with a disproportionality analysis using the Japanese Adverse Drug Event Report (JADER) database and evaluated the prevalence of MMI and PTU prescriptions using the National Database of Health Insurance Claims and Specific Health Checkups (NDB) Open Data Japan. We analyzed 3271 cases of MMI use and 1029 cases of PTU use with respect to 9789 preferred terms (PTs) for adverse events registered in the JADER database by calculating and comparing reporting odds ratios (RORs). Results: We found that 8 PTs, including agranulocytosis (p < 0.0001, 4.01-fold), aplasia cutis congenita (p < 0.0001, 123.22-fold), and exomphalos (p = 0.0002, 22.17-fold), demonstrated significantly higher RORs (more than 4-fold) for MMI use than for PTU use. Nineteen PTs, including anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (p < 0.0001, 29.84), rapidly progressive glomerulonephritis (p < 0.0001, 6.44), and pulmonary alveolar hemorrhage (p < 0.0001, 7.77), had RORs for PTU use more than four times those for MMI use. NDB Open Data Japan showed more frequent PTU prescriptions than MMI prescriptions for women of reproductive age. Conclusions: This large-scale study confirmed that a variety of congenital malformations were identified as having significantly high RORs for MMI use, while diseases related to ANCA-associated vasculitis were specific to PTU.

Comparison of the safety between propylthiouracil and methimazole with hyperthyroidism in pregnancy: A systematic review and meta-analysis.

OBJECTIVE: The purpose of this meta-analysis was to assess the safety of the anti-thyroid drugs (ATDs) propylthiouracil (PTU) and methimazole (MMI) in the treatment of hyperthyroidism during pregnancy. METHOD: From inception until June 2, 2022, all available studies were searched in PubMed, Web of Science, Cochrane, EBSCO, Embase, Scopus, and CNKI. RESULT: Thirteen articles satisfying the inclusion criteria were examined. Our meta-analysis indicated that pregnant women treated with MMI had a higher risk of congenital anomalies than those treated with PTU (OR 0.80, 95%CI 0.69-0.92, P = 0.002, I2 = 41.9%). Shifting between MMI and PTU during pregnancy did not reduce the risk of birth defects compared to PTU alone (OR 1.18, CI 1.00 to 1.40, P = 0.061, I2 = 0.0%). There were no statistically significant differences in hepatotoxicity (OR 1.54, 95%CI 0.77-3.09, P = 0.221, I2 = 0.0%) or miscarriage (OR 0.89, 95%CI 0.72-1.11, P = 0.310, I2 = 0.0%) between PTU and MMI exposure. CONCLUSION: The study confirmed propylthiouracil is a safer alternative to methimazole for treating hyperthyroidism in pregnant women, and it is appropriate to treat maternal thyroid disease with PTU during the first trimester of pregnancy. However, it is not clear whether switching between propylthiouracil and methimazole is a better option than treating PTU alone during pregnancy. Further studies on this matter may be needed to develop new evidence-based guidelines for the treatment of pregnant women with hyperthyroidism.

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.

Comparative effectiveness and safety of topical methimazole 5% monotherapy versus combination of Q-Switched Nd: YAG Laser and topical methimazole 5% in patients with refractory melasma.

INTRODUCTION: Melasma is an acquired pigmentary disorder which currently has no definitive treatment. Although topical drugs containing hydroquinone are the basis of treatments, they are usually associated with recurrence. We aimed to evaluate the effectiveness and safety of monotherapy with topical methimazole 5% versus combination of Q-Switched Nd: YAG Laser and topical methimazole 5% in patients with refractory melasma. METHODS: A total of 27 women with refractory melasma were included. We applied topical methimazole 5% (once a day) with three passes of QSNd: YAG laser (Wavelength: 1064 nm, pulse energy: 750 mJ, fluence: 1.50  J/cm2 , spot size: 4 × 4 mm, hand piece: fractional, JEISYS company) for six sessions on the right half of the face, and topical methimazole 5% (once a day) on the left half of the face, for each patient. The treatment course was 12 weeks. Evaluation of effectiveness was done with the Physician Global Assessment (PGA), Patient Global Assessment (PtGA), Physician satisfaction (PS), Patients satisfaction (PtS), and mMASI score. RESULTS: PGA, PtGA, and PtS were not significantly different between the two groups at any time (p > 0.05). PS in the laser plus methimazole group was significantly better than methimazole group at 4th, 8th, and 12th weeks (p < 0.05). The rate of PGA improvement in the combination group was significantly better than the monotherapy over time (p < 0.001). The changes of mMASI score between the two groups did not significantly differ at any time (p > 0.05). There was no significant difference in the adverse events between the two groups. CONCLUSION: Combination therapy with topical methimazole 5% and QSNY laser can be considered as an effective way to treat refractory melasma.

[Clinical discussion on methimazole in the treatment of hyperthyroidism].

Methimazole is the most commonly used medication for hyperthyroidism with good effects and little adverse reactions. However, improper selection of initial dose will affect the efficacy, such as excessive dose is proven to various adverse reactions; insufficient dose can hardly achieve desired efficacy. Based on the literature and personal clinical experience, the author discusses the following clinical issues related to methimazole in the treatment of hyperthyroidism, including the selection of initial dose, dose adjustment and withdrawal of methimazole, drug therapy for patients with liver function injury, and management strategies for methimazole-related adverse reactions.

Long-Term Follow-up of Graves Orbitopathy After Treatment With Short- or Long-Term Methimazole or Radioactive Iodine.

OBJECTIVE: The aim of this study was to compare long-term outcomes in terms of new onset or worsening of Graves orbitopathy (GO) in patients with Graves disease treated with different therapeutic modalities for hyperthyroidism. METHODS: A total of 1163 patients with Graves disease were enrolled in this study; 263 patients were treated with radioiodine and 808 patients received methimazole (MMI) therapy for a median of 18 months, of whom 178 patients continued MMI for a total of 96 months (long-term methimazole [LT-MMI]). The thyroid hormonal status and GO were evaluated regularly for a median of 159 months since enrollment. RESULTS: The rates of relapse, euthyroidism, and hypothyroidism at the end of follow-up were as follows: radioiodine treatment group: 16%, 22%, and 62%, respectively; short-term MMI group: 59%, 36%, and 5%, respectively; and LT-MMI group: 18%, 80%, and 2%, respectively. During the first 18 months of therapy, worsening of GO (11.5% vs 5.7%) and de novo development of GO (12.5% vs 9.8%) were significantly more frequent after radioiodine treatment (P <.004). Overall worsening and de novo development of GO from >18 to 234 months occurred in 26 (9.9%) patients in the radioiodine group and 8 (4.5%) patients in the LT-MMI group (P <.037). No case of worsening or new onset of GO was observed in patients treated with LT-MMI from >60 to 234 months of follow-up. CONCLUSION: Progression and development of GO were associated more with radioiodine treatment than with MMI treatment; GO may appear de novo or worsen years after radioiodine treatment but not after LT-MMI therapy.

Characterizing Granulocytopenia Associated with Thiamazole in Patients with Hyperthyroidism Based on Real-World Data from the MID-NET in Japan.

Despite the requirement of routine blood tests during thiamazole treatment in Japan, granulocytopenia among patients treated with thiamazole has been occasionally reported to the Pharmaceuticals and Medical Devices Agency (PMDA). To characterize granulocytopenia in patients with thiamazole in Japan, the effects of routine blood tests were examined in a cohort of new users of thiamazole or propylthiouracil utilizing the MID-NET. The occurrence of granulocytopenia (neutrophil count ≤ 1,500/µL) in a given period was compared between patients with and without blood test results prior to the period. The trend in neutrophil count during thiamazole treatment was also compared between patients with and without granulocytopenia. A nested case-control study based on the cohort was conducted to identify potential risk factors for granulocytopenia during thiamazole treatment. In the new user cohort including 4,371 patients treated with thiamazole, the occurrence of granulocytopenia in patients who had undergone blood tests at all previous periods was similar or higher than that among those who had not undergone blood test in all previous periods (e.g., adjusted odds ratio in period 2 was 1.63). The neutrophil count was relatively lower in the group of patients with granulocytopenia even before the occurrence of granulocytopenia. In a nested case-control study, an upward tendency of the risk was observed when a patient was co-prescribed anti-arrhythmic drugs or antiulcer drugs with thiamazole. The characteristics of granulocytopenia during thiamazole treatment elucidated in this study should be recognized in clinical practice for the proper use of thiamazole.

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.

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.

Acute pancreatitis caused by methimazole/carbimazole assumption: a case-series.

The World Health Organization (WHO) has listed 525 different drugs, that can lead to acute pancreatitis cases, as a medication side-effect. Among them, methimazole (MMI also known as thiamazole, the active form of carbimazole [CBZ]) was included. We reported case reports of patients with overall features compatible with acute pancreatitis episodes following and presumably triggered by the exposure to MMI and its prodrug CBZ. A systematic search was performed on MEDLINE (PubMed). We included case reports of patients with overall features compatible with acute pancreatitis episodes following and presumably triggered by the exposure to MMI and its prodrug CBZ Data extraction and analysis were undertaken in duplicate. We identified 7 case reports. Most patients were female, and one patient was male. Mean age at baseline ranged from 18 to 80 years old. The average time, that elapses between the initiation of the therapy with MMI/CBZ and the onset of typical clinical signs and symptoms pathognomonic of acute pancreatitis, was 2-3 weeks. Based on the data derived from these case reports, it could be considered the possibility of a potential association between MMI/CBZ exposure. Evidence is, however, limited and requires more studies of high quality to confirm this association.