Adalimumab-Induced Acute Pancreatitis in a Patient with Ulcerative Colitis: An Unusual Case

Background: Drug-induced acute pancreatitis is a rare but well-recognized entity, accounting for less than 5% of all cases of acute pancreatitis. Numerous medications have been implicated, with varying levels of evidence. Tumor necrosis factor-alpha (TNF-α) inhibitors, widely used in inflammatory bowel disease, are only exceptionally reported as a cause of acute pancreatitis, mainly through isolated case reports in the literature. Case Presentation: We report the case of a 28-year-old woman with extensive ulcerative colitis (pancolitis), initially treated with azathioprine for five years with insufficient efficacy. Therapy with adalimumab was initiated according to the standard induction regimen. Ten weeks after treatment initiation, the patient developed epigastric pain associated with a serum lipase level exceeding six times the upper limit of normal, leading to the diagnosis of acute pancreatitis without severity criteria. Abdominal imaging confirmed mild edematous acute pancreatitis (Balthazar stage C). Etiological workup did not identify any alternative cause, including biliary, alcoholic, metabolic, or autoimmune origins. Discontinuation of adalimumab, combined with supportive management, resulted in a favorable outcome. Pharmacological assessment using the French method of causality evaluation concluded that the pancreatitis was probably drug-induced and attributable to adalimumab (imputability score I3B4). Treatment was subsequently switched to ustekinumab. Conclusion: Acute pancreatitis is a rare but possible complication of adalimumab therapy. This diagnosis should be considered in any patient receiving TNF-α inhibitors who presents with acute pancreatitis after exclusion of more common etiologies. Early recognition of this cause allows for appropriate management and the initiation of an alternative therapeutic strategy to prevent recurrence.