Acute pancreatitis induced by methimazole therapy

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.

The Role of Endoplasmic Reticulum Stress in Cell Injury Induced by Methimazole on Pancreatic Cells

Purpose: Methimazole is an anti-thyroid agent, especially as main therapy option for Graves' disease in children and adults. Drug induced pancreatitis is one of the known adverse effect of methimazole mentioned in case reports. However, the detailed molecular mechanisms of methimazole-induced pancreatitis are still unclear. In this study, the aim is to investigate the adverse effect of methimazole on pancreas cell stress mechanism and apoptosis. Methods: Cytotoxicity was evaluated in human pancreas/duct (PANC-1) cell line. Total oxidant (TOS) and antioxidant status (TAS) for oxidative stress index, glutathione (GSH) level and endoplasmic reticulum (ER) stress biomarkers were evaluated by ELISA. Reactive oxygen species (ROS) levels and apoptosis were evaluated by flow-cytometer. Results: The 30% inhibition rate concentration (IC₃₀) value was determined as 53 mM in PANC1 cells. The exposure concentrations were in the range of 0-40 mM for 48 hours. Methimazole might induce cellular stress conditions. ROS production increases depending on concentration, and this increase shows parallelism with the increase in ER stress biomarkers such as TOS, ERN1 and CASPASE12. Conversely, there was no significant difference between control and exposure groups in terms of apoptosis. Conclusion: In conclusion, methimazole might have triggered the mechanisms of inflammation or autophagy in the pancreatic cells. However, there is still a need for in vitro and in vivo studies including other cellular parameters related to apoptosis.

A case of methimazole-induced acute pancreatitis with an HLA allele causing antithyroid drug-induced agranulocytosis

Among the side effects of methimazole (MMI) for the treatment of Graves’ disease, MMI-induced acute pancreatitis (MIP) is a rare adverse reaction, with only 7 cases being reported to date. However, 2 large-scale population-based studies recently revealed that the risk of MIP was significantly higher, ranging from 0.02% to 0.56%. Although MIP is common in middle-aged and elderly Asian women, its pathogenesis remains largely unknown. We herein present a case of a 72-year-old Japanese woman with Graves’ disease who developed MIP 12 days after the initiation of MMI. The MMI was discontinued, the patient was switched to propylthiouracil (PTU) therapy, and pancreatitis gradually resolved. Serological human leukocyte antigen (HLA) typing identified HLA-DRB1*08:03:02. This HLA allele was previously detected in a patient with MIP and is one of the major risk factors for agranulocytosis induced by antithyroid drugs, including PTU as well as MMI. In cases of MIP, PTU is being considered as an alternative to MMI; however, its safety needs further investigation and patients require close monitoring after the switch to PTU. Further studies are warranted, particularly on the relationship between MIP and the presence of HLA alleles causing antithyroid drug-induced agranulocytosis.

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.

Ofloxacin-ornidazole fixed-dose combination medication-induced pancreatitis with positive rechallenge

Although ofloxacin-ornidazole fixed-dose combination (FDC) is a rampantly used antibiotic combination for mixed-infection diarrhea in India, the adverse drug reaction (ADR) associated with these FDCs remains underreported. Herein, the authors present a case report of a definitive ofloxacin-ornidazole FDC-induced pancreatitis. The nonalcoholic adult male patient showed a sharp piercing epigastric pain flowing to the back, gradually rising in severity, which started after taking ofloxacin-ornidazole FDC tablet over the counter. Serum lipase concentration measured in the emergency room was 635 units per liter (normal range- 13–60 units/L) and serum amylase was 377 units/L (normal range- 30–110 units/L). Ultrasonography and an axial computed tomography of the abdomen confirmed the diagnosis of acute pancreatitis. Ofloxacin-ornidazole FDC tablet was stopped immediately. Past treatment records confirmed accidental rechallenge. In conclusion, this is a first case report of ofloxacin-ornidazole FDC-induced pancreatitis.

Drug induced pancreatitis: A systematic review of case reports to determine potential drug associations

OBJECTIVE

A current assessment of case reports of possible drug-induced pancreatitis is needed. We systematically reviewed the case report literature to identify drugs with potential associations with acute pancreatitis and the burden of evidence supporting these associations.

METHODS

A protocol was developed a priori (PROSPERO CRD42017060473). We searched MEDLINE, Embase, the Cochrane Library, and additional sources to identify cases of drug-induced pancreatitis that met accepted diagnostic criteria of acute pancreatitis. Cases caused by multiple drugs or combination therapy were excluded. Established systematic review methods were used for screening and data extraction. A classification system for associated drugs was developed a priori based upon the number of cases, re-challenge, exclusion of non-drug causes of acute pancreatitis, and consistency of latency.

RESULTS

Seven-hundred and thirteen cases of potential drug-induced pancreatitis were identified, implicating 213 unique drugs. The evidence base was poor: exclusion of non-drug causes of acute pancreatitis was incomplete or poorly reported in all cases, 47% had at least one underlying condition predisposing to acute pancreatitis, and causality assessment was not conducted in 81%. Forty-five drugs (21%) were classified as having the highest level of evidence regarding their association with acute pancreatitis; causality was deemed to be probable or definite for 19 of these drugs (42%). Fifty-seven drugs (27%) had the lowest level of evidence regarding an association with acute pancreatitis, being implicated in single case reports, without exclusion of other causes of acute pancreatitis.

DISCUSSION

Much of the case report evidence upon which drug-induced pancreatitis associations are based is tenuous. A greater emphasis on exclusion of all non-drug causes of acute pancreatitis and on quality reporting would improve the evidence base. It should be recognized that reviews of case reports, are valuable scoping tools but have limited strength to establish drug-induced pancreatitis associations.

REGISTRATION

CRD42017060473.

Safety of antithyroid drugs in pregnancy: update and therapy implications

Introduction: The thionamide antithyroid drugs, methimazole (MMI), its pro-drug derivative carbimazole (CMZ), and propylthiouracil (PTU) are the mainstay of treatment for hyperthyroidism in pregnancy. However, antithyroid drugs carry risks of adverse effects that can affect fetal and maternal well-being.Areas covered: This review provides an update on the safety of antithyroid drugs in pregnancy, focusing on the most serious concerns of severe liver disease and congenital anomalies.Expert opinion: PTU-induced liver disease is uncommon but can run a catastrophic course in pregnancy with a risk of liver failure and threats to maternal or fetal survival. Acute pancreatitis is a relatively rare occurrence that has been linked to thionamide use in a handful of reports in non-pregnant individuals. Observational studies on the risk of birth defects with antithyroid drug exposure in pregnancy overall show an increase in birth defect risk with exposure to CMZ/MMI, and to a lesser extent, PTU. Further studies are required to determine whether the currently recommended approach of switching between thionamide drugs in pregnancy improves outcomes. Ultimately, a preventative strategy of offering definitive therapy to hyperthyroid women of childbearing potential offers the best approach to truly reduce the risks of antithyroid drug adverse effects in pregnancy.

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.

Use of methimazole and risk of acute pancreatitis: A case-control study in Taiwan

Objective:

Some cases of acute pancreatitis have been reported to be associated with use of methimazole. The aim of this study was to investigate the relationship between use of methimazole and risk of acute pancreatitis on the basis of a systematic analysis.

Methods:

This was a population-based case–control study analyzing the database of the Taiwan National Health Insurance Program. There were 5764 individuals aged 20–84 years with a first attack of acute pancreatitis from 1998 to 2011 as the cases and 23,056 randomly selected sex- and age-matched individuals without acute pancreatitis as the controls. Use of methimazole was categorized as “never use” and “ever use.” We estimated the relative risk of acute pancreatitis associated with the use of methimazole by calculating the odds ratio (OR) with 95% confidence interval (CI) using a multivariable logistic regression model.

Results:

After adjustment for confounding factors, the OR of acute pancreatitis was 0.91 in individuals with ever use of methimazole, when compared with individuals with never use of methimazole (95% CI, 0.60–1.38). Unlike methimazole use, alcohol-related disease, biliary stone, cardiovascular disease, chronic obstructive pulmonary disease, diabetes mellitus, hepatitis B, hepatitis C, and hypertriglyceridemia were factors significantly associated with acute pancreatitis.

Conclusions:

Our study does not detect a substantial association between the use of methimazole and risk of acute pancreatitis on the basis of systematic analysis. There appears to be a discrepancy between case reports and our systematic analysis about the association between the use of methimazole and risk of acute pancreatitis.

Acute Pancreatitis Induced by Methimazole in a Patient With Subclinical Hyperthyroidism

We report here a unique case of methimazole (MMI)-induced pancreatitis. To our knowledge, this is the sixth case reported in the literature and the first diagnosed in a patient with toxic multinodular goiter. A 51-year-old Caucasian female with a history of benign multinodular goiter and subclinical hyperthyroidism was started on MMI 10 mg orally daily. Three weeks later, she developed sharp epigastric pain, diarrhea, lack of appetite, and fever. Her lipase was elevated 5 times the upper limit of normal, consistent with acute pancreatitis. There was no history of hypertriglyceridemia, or alcohol abuse. Abdominal computed tomography was consistent with acute uncomplicated pancreatitis, without evidence of gallstones or tumors. MMI was discontinued, and her hyperthyroid symptoms were managed with propranolol. Her acute episode of pancreatitis quickly resolved clinically and biochemically. One year later, she redeveloped mild clinical symptoms of hyperthyroidism with biochemical evidence of subclinical hyperthyroidism. MMI 10 mg orally daily was restarted. Five days later, she experienced progressive abdominal discomfort. Her lipase was elevated 12 times the upper limit of normal, and the abdominal computed tomography was again compatible with acute uncomplicated pancreatitis. MMI was again discontinued, which was followed by rapid resolution of her pancreatitis. The patient is currently considering undergoing definitive therapy with radioactive iodine ablation. Our case as well as previous case reports in the literature should raise awareness about the possibility of pancreatitis in subjects treated with MMI in the presence of suggestive symptoms. If the diagnosis is confirmed by elevated pancreatic enzymes, the drug should be discontinued.

Acute pancreatitis induced by methimazole treatment in a 51-year-old korean man: a case report

Methimazole (MMI)-induced acute pancreatitis is very rare but severe adverse reaction. A 51-yr-old male developed a high fever, chills, and abdominal pain, two weeks after commencement on MMI for the treatment of Graves' disease. There was no evidence of agranulocytosis, and fever subsided soon after stopping MMI treatment. However, 5 hr after taking an additional dose of MMI, abdominal pain and fever developed again. His symptoms, biochemical, and imaging studies were compatible with acute pancreatitis. After withdrawal of MMI, he showed clinical improvement. This is the first case of MMI-induced acute pancreatitis in Korea. Clinicians should be aware of the rare but possible MMI-induced pancreatitis in patients complaining of fever and abdominal pain.