S3505 Acute Pancreatitis Following a Recent COVID-19 Infection and Antimicrobial Therapy: A Case for Pharmacovigilance

Introduction: Drug-induced acute pancreatitis (DIAP) is an underrecognized condition due to its diagnostic challenges. While a large number of medications has been associated with DIAP, the incidence of this entity remains underestimated. We report a case of tail-predominant acute pancreatitis mimicking renal pathology in a patient following a recent coronavirus disease 2019 (COVID-19) infection and use of Paxlovid and cephalexin. Case Description/Methods: A 67-year-old woman with a history of hypertension, recently treated with Paxlovid for COVID-19 (Feb 25–Mar 2) and Cephalexin for a urinary tract infection (Mar 6–8), presented on Mar 9 with severe left flank pain. Initial evaluation revealed temperature 100.2°F, heart rate 125 bpm, respiratory rate 26 rpm, and left flank tenderness. Further assessment showed elevated white blood cell count (WBC 17,000/μL), ESR (18 mm/h), C-reactive protein (9.4 mg/L), amylase (191 U/L) and lipase (139 U/L), with normal triglycerides. Urolithiasis and acute pyelonephritis were strongly suspected prompting imaging of the abdomen. Surprisingly, computer tomography revealed acute pancreatitis localized to the pancreatic tail, with early pseudocyst formation and extension into the left perirenal space. Magnetic resonance cholangiopancreatography (MRCP) confirmed a 1.5 cm hyperintense lesion in the tail consistent with focal pancreatitis. Management included discontinuation of the agents, bowel rest, intravenous fluids, and analgesia, which resulted in resolution of the pain and tolerance of oral intake by hospital day 2. Discharge occurred on day 3. A 2-week outpatient follow-up computed tomography confirmed a stable pseudocyst. Endoscopic ultrasound (EUS) revealed a side-branch intraductal papillary mucinous neoplasm (IPMN) in the pancreatic tail, which did not communicate with the main pancreatic duct. Discussion: This case underscores a rare but clinically relevant condition—drug-induced acute pancreatitis—potentially associated with the sequential use of Paxlovid and Cephalexin following a COVID-19 infection. The close association between infection, initiation of each agent, and symptoms onset suggest a possible idiosyncratic or accumulative toxic effect, rather than the impact of the incidental non-communicating IPMN. Tail-dominant acute pancreatitis may mimic renal pathology, which can only be unmasked by high-quality care including detailed imaging. Reconsidering the presumptive diagnosis, suspecting a medication interaction, and contributing to pharmacovigilance efforts should be priority to healthcare providers.