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

Carbimazole-associated Pancreatitis: Report From Western India

Pancreatitis is a very rare complication of methimazole and carbimazole therapy. We describe a case of possible carbimazole-associated pancreatitis. A 41-year-old Asian man (with no comorbidities) reported to the hospital with atrial fibrillation and a fast ventricular rate. He was diagnosed with hyperthyroidism due to Graves disease. His rhythm was reverted with amiodarone, and carbimazole was initiated at 15 mg daily for the medical management of Graves disease. Fifteen days later, he presented with acute severe abdominal pain and vomiting with elevated serum amylase 387 U/L (reference range, 28-100 U/L) and lipase levels 206 U/L (reference range, 13-60 U/L). Magnetic resonance imaging showed a bulky pancreas with extensive extrapancreatic fat stranding suggestive of acute pancreatitis. Considering the possibility of carbimazole-related pancreatitis, the drug was withheld. He was managed conservatively, and his pancreatic enzymes normalized within 1 week. The observation suggests that the pancreatitis was a consequence of the therapy with carbimazole. Although it is a rare occurrence, patients taking carbimazole who report abdominal discomfort and vomiting should be evaluated for pancreatitis.