Sudden onset agranulocytosis and hepatotoxicity after taking methimazole

Novel Association of KLRC4-KLRK1 Gene Polymorphisms with Susceptibility and Progression of Antithyroid Drug-Induced Agranulocytosis

OBJECTIVE

Antithyroid drug (ATD)-induced agranulocytosis (TIA) is the most serious adverse effect during ATD treatment of Graves' disease (GD). Previously, the MICA gene was reported to be associated with TIA. MICA protein is an important ligand for the NKG2D protein, which is encoded by the KLRK1 gene and KLRC4-KLRK1 read-through transcription. This study further investigated the association between KLRC4-KLRK1 gene polymorphisms and susceptibility to TIA.

METHODS

Twenty-eight candidate single nucleotide polymorphisms (SNPs) on KLRC4-KLRK1 read-through transcription were evaluated by the iPLEX MassARRAY system in 209 GD control patients and 38 TIA cases.

RESULTS

A significant association of rs2734565 polymorphism with TIA was found (p=0.02, OR=1.80, 95% CI=1.09-2.96). The haplotype C-A-A-C-G, including rs2734565-C, was associated with a significantly higher risk of TIA (p=4.79E-09, OR=8.361, 95% CI=3.737-18.707). In addition, the interval time from hyperthyroidism to agranulocytosis onset was shorter in patients carrying the rs2734565-C allele than in non-carrying groups (45.00 (14.00-6570.00) d vs. 1080.00 (30.00-3600.00) d, p=0.046), and the interval from ATD treatment to agranulocytosis onset was also shorter in patients carrying rs2734565-C allele (29.00 (13.00-75.00) d vs. 57.50 (21.00-240.00) d, p=0.023).

CONCLUSIONS

The findings suggest that the KLRC4-KLRK1 gene polymorphism is associated with susceptibility and progression of ATD-induced agranulocytosis. Patients carrying the rs2734565-C allele had a higher susceptibility and faster onset time of TIA.

Case report: Severe cholestatic jaundice associated with hyperthyroidism treated with methimazole

RATIONALE

We present a case of a 43-year-old female patient diagnosed with hyperthyroidism. This study aims to demonstrate the rare association between hyperthyroidism and severe cholestatic jaundice, and the effectiveness of methimazole treatment.

PATIENT CONCERNS

The patient developed severe jaundice, a typically mild symptom in most hyperthyroidism cases.

DIAGNOSIS

The severe jaundice was suspected to be a result of cholestasis induced by hyperthyroidism, with other potential causes such as drug-induced or autoimmune liver dysfunction being ruled out.

OUTCOMES

The patient was effectively treated with methimazole. Outcomes: Treatment with methimazole alleviated the severe cholestatic jaundice and restored normal thyroid function.

LESSONS

The specific mechanism of cholestasis as a secondary complication of hyperthyroidism remains unclear, and there are no specific biochemical markers for cholestasis caused by this hormonal disease. This case underscores the possibility of severe jaundice as a clinical manifestation of hyperthyroidism, and highlights antithyroid drug treatment as an effective strategy for managing severe cholestatic jaundice.

Concomitant methimazole-induced agranulocytosis and cholestatic jaundice in a young woman

A woman in her 30s presented to the emergency department with new-onset sore throat and fever. She had recently been diagnosed with Graves' disease 3 months prior. As a result, she was initiated on atenolol and methimazole for management. Her methimazole dosing had been stable at 15 mg daily for the month prior to presentation. Investigation revealed severe neutropenia and jaundice. She was found to have concomitant agranulocytosis and cholestatic jaundice secondary to methimazole.Methimazole was discontinued on admission and the patient received granulocyte colony-stimulating factor for an absolute neutrophil count (ANC) of zero. She was placed on broad-spectrum antibiotics and intravenous steroids for epiglottic and supraglottic oedema noted on bedside laryngoscopy. ANC and bilirubin improved over a 2-week hospital course. She was discharged on a temporary regimen of propranolol, dexamethasone and potassium iodide until she was able to undergo successful thyroidectomy for definitive management of Graves' disease outpatient.

Acute Iatrogenic Agranulocytosis: A Rare and Dire Case of an Adverse Drug Reaction to Be Aware

Background

Iatrogenic agranulocytosis (IA), by nonchemotherapeutic drugs, is a rare adverse event, resulting in a neutrophil count under 0.5 × 10⁹ cells/L with fever or other suggestive signs of infection.

Methods

This paper discusses the possible mechanisms responsible for agranulocytosis induced by nonchemotherapeutic drugs. It also describes three cases as well as potential ways to handle such iatrogenic situations.

Conclusion

Neutropenia under 0.1 × 10⁹ cells/L predispose patients to potentially fatal infections. Empiric broad-spectrum antibiotic and hematopoietic growth factors may be helpful in shortening hospitalization and prevent further infectious complications. Not all drugs associated with IA require frequent hematological monitoring, except medications such as clozapine, ticlopidine, and antithyroids.

Thyroid Disease in Lupus: An Updated Review

In the following review, we seek to provide an overview of the current understanding of various thyroid manifestations affecting patients with systemic lupus erythematosus (SLE), including topics ranging from thyroid‐related complications to SLE in pregnancy. Autoimmune diseases tend to coincide, and an association between thyroid disease and SLE has been reported for more than 50 years. There is no evidence that the coexistence of thyroid disease and lupus alters the disease course or manifestations of either. Both hypothyroidism and thyroid nodules are seen more frequently in patients with SLE than in the general population. The rate of thyroid cancer is twice as prevalent in patients with SLE compared with those without SLE. Several forms of thyroid disease are more common among patients with SLE, with adverse consequences in pregnancy. Future work will require delineating the mechanism behind these associations and understanding the role of antirheumatic agents with concomitant thyroid disease.

Drug-Induced Liver Injury: A Unique Presentation of Single-Dose Administration of Propylthiouracil

Antithyroid drug-induced severe liver injury is an uncommon but serious complication. We hereby delineate the case of a 38-year-old female who presented to the emergency department for an impending thyroid storm. After initiation of a single dose of propylthiouracil, her liver enzymes went into the thousands. She was subsequently admitted to the intensive care unit. Propylthiouracil was discontinued and corticosteroids were initiated with the resolution of her elevated liver enzymes. On follow-up, her liver function was at its baseline and thyroid hormone levels were under control. We hope this report will encourage clinicians to cast a broad differential diagnosis in patients presenting with liver injury in the acute setting. Furthermore, it is imperative to raise awareness regarding the ever-increasing list of pharmacologic agents that can perpetuate drug-induced hepatotoxicity.

Association between genetic polymorphisms of SLCO1B1 and susceptibility to methimazole-induced liver injury

Methimazole (MMI) has been used in the therapy of Grave's disease (GD) since 1954, and drug-induced liver injury (DILI) is one of the most deleterious side effects. Genetic polymorphisms of drug-metabolizing enzymes and drug transporters have been associated with drug-induced hepatotoxicity in many cases. The aim of this study was to investigate genetic susceptibility of the drug-metabolizing enzymes and drug transporters to the MMI-DILI. A total of 44 GD patients with MMI-DILI and 118 GD patients without MMI-DILI development were included in the study. Thirty-three single nucleotide polymorphisms (SNPs) in twenty candidate genes were genotyped. We found that rs12422149 of SLCO2B1, rs2032582_AT of ABCB1, rs2306283 of SLCO1B1 and rs4148323 of UGT1A1 exhibited a significant association with MMI-DILI; however, no significant difference existed after Bonferroni correction. Haplotype analysis showed that the frequency of SLCO1B1*1a (388A521T) was significantly higher in MMI-DILI cases than that in the control group (OR = 2.21, 95% CI = 1.11-4.39, P = 0.023), while the frequency of SLCO1B1*1b (388G521T) was significantly higher in the control group (OR = 0.52, 95% CI = 0.29-0.93, P = 0.028). These results suggested that genetic polymorphisms of SLCO1B1 were associated with susceptibility to MMI-DILI. The genetic polymorphism of SLCO1B1 may be important predisposing factors for MMI-induced hepatotoxicity.

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.

Emphasis on the early diagnosis of antithyroid drug-induced agranulocytosis: retrospective analysis over 16 years at one Chinese center

PURPOSE

Antithyroid drug (ATD)-induced agranulocytosis is a rare but life-threatening adverse drug reaction that occurs in patients during the treatment of Graves' disease. We aimed to comprehensively examine data for patients with this rare complication and to improve the clinical safety of ATDs.

METHODS

We retrospectively reviewed the medical records of 64 hospitalized patients diagnosed with ATD-induced agranulocytosis between 2000 and 2015.

RESULTS

Agranulocytosis occurred in 52 (81.3%) patients within the first 3 months after initiation of ATD therapy. Fever (84.4%) and sore throat (82.8%) were the most common symptoms. Although they experienced symptoms, 30 (46.9%) patients did not seek treatment immediately and delayed their diagnosis of agranulocytosis. The minimum granulocyte count was lower in the patients diagnosed after the appearance of symptoms than in those diagnosed before the appearance of symptoms (0.01 × 10⁹/L (0 × 10⁹/L - 0.06 × 10⁹/L) versus 0.26 × 10⁹/L (0.05 × 10⁹/L - 0.40 × 10⁹/L), P < 0.001). The interval days from the appearance of symptoms to the diagnosis of agranulocytosis were negatively correlated with the minimum granulocyte count (r = -0.348, P = 0.005). In addition, a lower minimum granulocyte count was associated with a longer recovery time (β = -11.899, 95% CI -15.304 to -8.496).

CONCLUSIONS

Our findings have demonstrated that delayed diagnosis of ATD-induced agranulocytosis is common in our population. Delayed diagnosis is associated with severe agranulocytosis and may prolong the recovery time from agranulocytosis. Monitoring of the white blood cell and granulocyte counts may be an effective way to establish an early diagnosis and prevent progression to severe agranulocytosis.

Factors predicting abnormal liver function tests induced by Graves' disease alone: a retrospective cohort study

Abnormal liver function tests (LFTs) are often observed in patients with Graves' disease (GD). To date, there are limited data demonstrating the factors or biochemical indexes contributing to LFT abnormalities in this patient population. The aim of this study was to explore factors predicting abnormal LFTs induced by GD alone. This was a retrospective study of 289 consecutive cases of newly diagnosed and untreated patients with GD. All patients were divided into abnormal LFTs (group A) and normal LFTs (group B). In total, 205 (70.9%) cases were found to have at least 1 LFT abnormality. Among them, the frequencies of ALT, AST, ALP, γ-GTP, TBIL and DBIL abnormalities were 52.7%, 32.2%, 45.9%, 38.5%, 23.4%, 2.9%, respectively, and the number of patients with 1 to 6 hepatic variable abnormalities were 89, 64, 30, 16, 6 and 0, respectively. Logistic regression analysis was used to determine predictive factors contributing to abnormal LFTs. A receiver operating characteristic (ROC) curve was also plotted to verify the accuracy of predictors. In the univariate analysis, patients in group A had significantly higher FT3 concentration (37.5 vs 33.4 pmol/L, P = 0.009), FT4 concentration (85.7 vs 77.4 pmol/L, P = 0.002) and TRAb level (22.2 vs 17.4 IU/L, P < 0.001) when compared with those in group B. Binary logistic regression analysis identified higher FT4 concentration (odds ratio [OR]: 1.017, 95% confidence interval [CI]: 1.005-1.030, P = 0.006) and higher TRAb value (OR: 1.038, 95% CI:1.013-1.064, P = 0.003) to be independent risk factors predicting abnormal LFTs. The optimal cutoffs for FT4 and TRAb to predict abnormal LFTs were 75 pmol/L and 15 IU/L, respectively, based on ROC analysis.

An overview on the proposed mechanisms of antithyroid drugs-induced liver injury

Drug-induced liver injury (DILI) is a major problem for pharmaceutical industry and drug development. Mechanisms of DILI are many and varied. Elucidating the mechanisms of DILI will allow clinicians to prevent liver failure, need for liver transplantation, and death induced by drugs. Methimazole and propylthiouracil (PTU) are two convenient antithyroid agents which their administration is accompanied by hepatotoxicity as a deleterious side effect. Although several cases of antithyroid drugs-induced liver injury are reported, there is no clear idea about the mechanism(s) of hepatotoxicity induced by these medications. Different mechanisms such as reactive metabolites formation, oxidative stress induction, intracellular targets dysfunction, and immune-mediated toxicity are postulated to be involved in antithyroid agents-induced hepatic damage. Due to the idiosyncratic nature of antithyroid drugs-induced hepatotoxicity, it is impossible to draw a specific conclusion about the mechanisms of liver injury. However, it seems that reactive metabolite formation and immune-mediated toxicity have a great role in antithyroids liver toxicity, especially those caused by methimazole. This review attempted to discuss different mechanisms proposed to be involved in the hepatic injury induced by antithyroid drugs.

Methimazole Associated Neutropenia in a Preterm Neonate Treated for Hyperthyroidism

Maternal Graves' disease is relatively uncommon with an estimated incidence of 0.4%–1% of all pregnancies, but only 1–5% of newborns delivered to mothers with Graves' disease develop overt clinical signs and symptoms of hyperthyroidism. Here, we describe a case of a 1380-gram female neonate who was born at 30-week gestation to a mother with Graves' disease. Our patient presented with hyperthyroidism followed by transient hypothyroidism requiring treatment with levothyroxine. While hyperthyroid, she was treated with methimazole, iodine, and a beta-blocker. 20 days after the initiation of methimazole, she developed neutropenia. The neutrophil counts started to improve immediately after the initiation of the weaning of methimazole. To the best of our knowledge, this is the first case reported in the literature of methimazole induced neutropenia in a preterm infant being treated for neonatal Graves' disease.

Patient knowledge of antithyroid drug-induced agranulocytosis

BACKGROUND

Agranulocytosis is a serious side effect of antithyroid drugs.

OBJECTIVE

To ascertain the knowledge of patients and review the quality of information available on the internet.

METHODS

A questionnaire survey was performed for patients receiving antithyroid drugs. Patients attending endocrine clinics who were receiving antithyroid drug treatment (group A, n = 33) were interviewed. A further national cohort of patients (group B, n = 100) treated with antithyroid drugs, participated in an online survey.

RESULTS

60.9% of responders were not aware of the common symptoms of agranulocytosis. 18.6% had never received any information about side effects. Of the 108 patients who recalled receiving information, 30% rated the quality as 'poor' or 'not good at all'. Structured interviews of group A patients revealed that almost half (45.5%, 15/33) had experienced symptoms that could be indicative of agranulocytosis, but only 53.3% (8/15) had a blood count checked. A review of 20 selected patient information internet sites revealed a significant variation in advice given to patients.

CONCLUSIONS

Inadequate knowledge about agranulocytosis among patients receiving antithyroid drug treatment is common. The available information on the internet is variable and inconsistent.

Mitigation of Methimazole-Induced Hepatic Injury by Taurine in Mice

Methimazole is the most widely prescribed antithyroid medication in humans. However, hepatotoxicity is a deleterious adverse effect associated with methimazole administration. No specific protective agent has been developed against this complication yet. This study was designed to investigate the role of taurine as a hepatoprotective agent against methimazole-induced liver injury in mice. Different reactive metabolites were proposed to be responsible for methimazole hepatotoxicity. Hence, methimazole-induced liver injury was investigated in intact and/or enzyme-induced animals in the current investigation. Animals were treated with methimazole (200 mg/kg, by gavage), and hepatic injury induced by this drug was investigated in intact and/or enzyme-induced groups. Markers such as lipid peroxidation, hepatic glutathione content, alanine aminotransferase (ALT) and alkaline phosphatase (ALP) in plasma, and histopathological changes in the liver of animals were monitored after drug administration. Methimazole caused liver injury as revealed by increased plasma ALT. Furthermore, a significant amount of lipid peroxidation was detected in the drug-treated animals, and hepatic glutathione reservoirs were depleted. Methimazole-induced hepatotoxicity was more severe in enzyme-induced mice. The above-mentioned alterations in hepatotoxicity markers were endorsed by significant histopathological changes in the liver. Taurine administration (1 g/kg, i.p.) effectively alleviated methimazole-induced liver injury in both intact and/or enzyme-induced animals.

Factors affecting drug-induced liver injury: antithyroid drugs as instances

Methimazole and propylthiouracil have been used in the management of hyperthyroidism for more than half a century. However, hepatotoxicity is one of the most deleterious side effects associated with these medications. The mechanism(s) of hepatic injury induced by antithyroid agents is not fully recognized yet. Furthermore, there are no specific tools for predicting the occurrence of hepatotoxicity induced by these drugs. The purpose of this article is to give an overview on possible susceptibility factors in liver injury induced by antithyroid agents. Age, gender, metabolism characteristics, alcohol consumption, underlying diseases, immunologic mechanisms, and drug interactions are involved in enhancing antithyroid drugs-induced hepatic damage. An outline on the clinically used treatments for antithyroid drugs-induced hepatotoxicity and the potential therapeutic strategies found to be effective against this complication are also discussed.

A method for the determination of total and reduced methimazole in various biological samples

A simple, rapid, reproducible and sensitive method based on HPLC with ultraviolet detection was developed for the determination of methimazole (MMI) in animal tissues and plasma samples. Under the optimum experimental conditions, the calibration curves for MMI were linear in the tested range 0.5-20 mg kg(-1) tissue sample (mg l(-1) plasma) with correlation coefficients better than 0.99. The performance of the proposed method was tested for the determination of MMI levels in brain, liver, thyroid gland and plasma of MMI-treated hens, as well as in their eggs and embryos. The proposed method reduces time and simplifies the sample preparation procedure.

Efficacy and safety of methimazole ointment for patients with hyperthyroidism

Oral methimazole has been widely used to treat hyperthyroidism, but its usage is restricted by its adverse systemic effects. The aim of this study was to investigate the efficacy and safety of methimazole ointment for the treatment of hyperthyroidism. One hundred forty-four subjects with hyperthyroidism were initially enrolled. These patients were initially divided into two groups and given the following treatments for 12 weeks: patients in group A received 5% methimazole ointment applied to the skin around the thyroid and an oral placebo; and patients in group B received methimazole tablets and placebo ointment. One hundred thirty-one subjects were included in the final analysis. Therapeutic efficacy was assessed via the levels of free triiodothyronine and thyroxine in the serum and by biweekly monitoring of the symptoms of thyrotoxicosis. Adverse effects were recorded. Fifty-nine (89.40%) patients in group A and 57 (87.69%) patients in group B were euthyroid and experienced alleviation of thyrotoxicosis symptoms (complete control; p>0.05). The median times required to achieve complete control for the patients in the two groups were 6.5 weeks and 6.4 weeks for groups A and B, respectively (p>0.05). Systemic adverse effects (e.g., rash, liver dysfunction, leucopenia, etc.) were significantly less common in group A (1.5%) than in group B (12.3%; p<0.05). This study showed that methimazole ointment has a clinical efficacy similar to that of oral tablets, but methimazole ointment caused fewer systemic adverse effects in patients with hyperthyroidism.

Maternal transfer of methimazole and effects on thyroid hormone availability in embryonic tissues

Methimazole (MMI) is an anti-thyroid drug used in the treatment of chronic hyperthyroidism. There is, however, some debate about its use during pregnancy as MMI is known to cross the mammalian placenta and reach the developing foetus. A similar problem occurs in birds, where MMI is deposited in the egg and taken up by the developing embryo. To investigate whether maternally derived MMI can have detrimental effects on embryonic development, we treated laying hens with MMI (0.03% in drinking water) and measured total and reduced MMI contents in the tissues of hens and embryos at different stages of development. In hens, MMI was selectively increased in the thyroid gland, while its levels in the liver and especially brain remained relatively low. Long-term MMI treatment induced a pronounced goitre with a decrease in thyroxine (T₄) content but an increase in thyroidal 3,5,3'-triiodothyronine (T₃) content. This resulted in normal T₃ levels in tissues except in the brain. In chicken embryos, MMI levels were similar in the liver and brain. They gradually decreased during development but always remained above those in the corresponding maternal tissues. Contrary to the situation in hens, T₄ availability was only moderately affected in embryos. Peripheral T₃ levels were reduced in 14-day-old embryos but normal in 18-day-old embryos, while brain T₃ content was decreased at all embryonic stages tested. We conclude that all embryonic tissues are exposed to relatively high doses of MMI and its oxidised metabolites. The effect of maternal MMI treatment on embryonic thyroid hormone availability is most pronounced for brain T₃ content, which is reduced throughout the embryonic development period.

The relationship between bone marrow characteristics and the clinical prognosis of antithyroid drug-induced agranulocytosis

This study is aimed to explore the relationship between bone marrow characteristics and clinical prognosis of antithyroid drug (ATD) induced agranulocytosis. A retrospective study was conducted in the first affiliated hospital of the University of South China. A total of 33 hospitalized patients diagnosed with ATD-induced agranulocytosis were analyzed. The bone marrow characteristics were classified into two types. Type I was characterized by reduction or absence of granulocytic precursors and type II was recognized as hypercellular bone marrow with dysmaturity of granulocytic cells. Bone marrow of 20 cases (61%) were characterized with type I whereas 13 cases (39%) with type II. The median duration of neutrophil recovery and high-grade fever were 4.7 ± 1.0 days and 3.6 ± 2.5 days respectively for type II, compared to 8.0 ± 2.8 days and 8.6 ± 3.1 days for type I (p < 0.01 in both compared groups). However, there was no significant difference between the two types in terms of age, median duration of drug administration before the diagnosis of agranulocytosis, the amount of neutrophil count on admission and the total administration dose of granulocyte-colony stimulating factor (G-CSF) before bone marrow examination. Two cases of type I died of complications from infection. This study showed that the bone marrow characteristics of ATD-induced agranulocytosis could be classifed into two types. Also, the clinical prognosis was closely related to the bone marrow features. Type I is the dominant type which is usually associated with worse clinical prognosis compared to type II.