SHM Converge Scientific Abstract ePoster Gallery-A Gut Reaction: Unmasking Leflunomide Toxicity

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This case describes a 64-year-old woman with rheumatoid arthritis treated with leflunomide who developed 2 months of dysphagia, vomiting, epigastric pain, malnutrition, and neutropenia. She had multiple prior admissions and an outside workup showing nonspecific gastritis/duodenitis, which initially led to ongoing treatment with a proton pump inhibitor. At the presenting hospital, labs showed leukopenia with neutropenia, mild hyponatremia, hypokalemia, and hypomagnesemia; other nutritional, infectious, and hepatic studies were unrevealing. CT abdomen/pelvis was unremarkable aside from diverticulosis, and esophagram showed ineffective esophageal motility without obstruction or reflux.<br /><br />Because symptoms and neutropenia persisted, leflunomide toxicity was suspected. A serum leflunomide level was elevated, and the drug was stopped. Rheumatology recommended accelerated drug elimination with cholestyramine washout, and she was temporarily switched to low-dose prednisone for RA control. Within 11 days of discontinuation, her leflunomide level fell to subtherapeutic range, her neutropenia and dysphagia resolved, and she was able to resume a regular diet. She remained asymptomatic at 3-month follow-up.<br /><br />The case highlights common leflunomide adverse effects, including nausea, diarrhea, hypertension, elevated liver enzymes, and rash, as well as serious toxicities such as cytopenias, severe rash, hepatitis, pneumonitis, neuropathy, and angioedema. GI toxicity is recognized, but a direct association with esophageal dysmotility or dysphagia is not established; however, symptoms in this patient resolved after stopping leflunomide, supporting causality.<br /><br />Management of suspected leflunomide toxicity includes immediate discontinuation and, because of its long half-life and enterohepatic recirculation, washout therapy—preferably cholestyramine or alternatively activated charcoal. The case also emphasizes avoiding anchoring and momentum bias when evaluating recurrent, unexplained symptoms across multiple encounters.

Asset Subtitle

Tara K. Ward

Meta Tag

Author List Sarah Scarpato, Tara K. Ward

Category Clinical Vignettes

Concept Leflunomide

Concept Leflunomide Toxicity

Concept Cytopenia

Concept Hematologic Monitoring

Concept Drug Discontinuation

Distinguished Non-Finalist

Presenter Organization University of Colorado Hospital

Presenting Author Tara K. Ward

Track Adult

Keywords

leflunomide toxicity

rheumatoid arthritis

dysphagia

neutropenia

cholestyramine washout

esophageal dysmotility

gastrointestinal toxicity

drug elimination

cytopenias

anchoring bias

Leflunomide

Leflunomide Toxicity

Cytopenia

Hematologic Monitoring

Drug Discontinuation