Granisetron as a Novel Treatment for Acute Food Protein-induced Enterocolitis Syndrome.

Acute food protein-induced enterocolitis syndrome (FPIES) is a non-immunoglobulin E-mediated food allergy characterized by delayed-onset vomiting, which can lead to severe dehydration and shock. Ondansetron, a 5-hydroxytryptamine 3 receptor antagonist, is recommended for managing acute episodes, but granisetron, a similar antiemetic, lacks global approval for FPIES. Our case series aimed to evaluate the effectiveness and safety of intravenous granisetron in acute FPIES episodes. We report three cases of infants with acute FPIES triggered by egg yolk during oral food challenges. Each patient received intravenous granisetron after multiple vomiting episodes. Clinical outcomes, including cessation of vomiting and resumption of oral intake, were assessed. Vomiting ceased within an hour after granisetron administration in all cases, allowing successful oral rehydration. No adverse effects or recurrence of symptoms were observed, and all patients were discharged the following day. The clinical outcomes were comparable to those reported for ondansetron. Our findings suggest that intravenous granisetron is a safe and effective secondary therapy for acute FPIES reactions. Given the limited evidence on granisetron for FPIES, accumulating case reports is essential for guiding clinical trials and regulatory approval. Further comparative studies of granisetron and ondansetron are warranted.