Iron pharmacobezoar and toxicity in a patient with Roux-En-Y gastric bypass: a case report

Introduction: Iron overdose and charcoal administration may cause pharmacobezoar formation. Altered gastrointestinal anatomy, such as in Roux-en-Y gastric bypass, may contribute to this. Case: A 50-year-old woman (80 kg) with a history of Roux-en-Y gastric bypass arrived after a multi-drug overdose, including ferrous fumarate, promethazine, desvenlafaxine, ibuprofen, thiamine, perindopril, paroxetine, escitalopram, paracetamol, and ethanol. She underwent gastric decontamination with activated charcoal and whole bowel irrigation (WBI). She received antidotal treatment with acetylcysteine and deferoxamine. In the hospital, she had positional hypotension, plateauing serum iron concentrations, and rising alanine aminotransferase activity despite deferoxamine chelation. WBI continued until she had clear rectal effluent on day 1. The charcoal-stained effluent returned on day 2 and coincided with hypotension requiring norepinephrine infusion. This prompted the resumption of WBI. Discussion: Altered gastric geometry due to Roux-en-Y gastric bypass surgery likely contributed to pharmacobezoar formation and erratic absorption, leading to the patient's unexpected clinical deterioration. Furthermore, deferoxamine chelation therapy may interfere with the serum iron assay, yielding misleading results.