S4189 Proton Pump Panic: A Shocking Surprise by Pantoprazole

Introduction: Proton pump inhibitors (PPIs) considered safe to use, can result in various adverse effects including hypomagnesemia, osteoporosis, vitamin B12 deficiency, severe acute hepatitis, thrombocytopenia, acute interstitial nephritis, and Steven Johnson Syndrome. Anaphylaxis is rare but life-threatening drug reactions secondary to PPI use. Here, we present a similar case of a patient presented with anaphylactic shock after taking oral pantoprazole. Case Description/Methods: A 57-year-old woman with a history of multiple medication allergies and a recent gastrointestinal bleed secondary to grade 2 internal hemorrhoids presented with a sudden onset of itching in both the arms and groin area at once followed by shortness of breath and unwitnessed loss of consciousness on standing. She was hypotensive to 65/41 mmHg, heart rate 81 beats/minute, saturating 96% on room air on initial presentation with labs concerning leukocytosis of 13.6. Symptoms started within a few minutes after taking the first dose of pantoprazole orally prescribed on an outpatient basis for concerns of gastritis and gastroesophageal reflux disorder. Per the patient, it was the only new medication she took before the onset of her above symptoms. She was subsequently admitted for the management of anaphylactic shock and received epinephrine intramuscularly along with fluid boluses with improvement in her symptoms within hours. Blood pressure improved to 126/67 mmHg. She was initiated on systemic steroids and loratadine for supportive care. Pantoprazole was switched to famotidine 40 mg twice daily on discharge. Discussion: PPIs are widely used medications for gastrointestinal disorders in the United States due to their increased potency and better tolerance than H2 receptor antagonists, easy over-the-counter availability, and affordability causing its exploitation for non-FDA approved conditions including uninvestigated dyspepsia, Barrett’s esophagus, esophageal stricture, risk reduction for NSAID associated peptic ulcer. It has led to a significant cost burden and serious adverse effects. Anaphylaxis is 1 such reaction caused by oral and parenteral PPI use. This case demands judicious medication use and efforts at even de-prescribing it when not indicated or no longer effective. It also highlights the importance of emergent recognition and management of adverse reactions like anaphylaxis by physicians that can occur due to benign medications like PPIs especially when co-administered with other drugs.