A Case Report of Systemic Allergic Reaction to the Dual Glucose-Dependent Insulinotropic Polypeptide/Glucagon-Like Peptide-1 Receptor Agonist Tirzepatide

Abstract

This report examines a case of systemic hypersensitivity to tirzepatide in a patient with type 2 diabetes. Tirzepatide (Mounjaro®), a dual agonist of glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor, has recently gained FDA approval. Additionally, a literature review was conducted to summarize recent research on tirzepatide's effectiveness and safety. A 67-year-old woman, previously treated with basal insulin, metformin, and semaglutide (a GLP-1 agonist), experienced severe disseminated pruritus and a generalized urticarial rash after her first dose of tirzepatide. This reaction, which subsided with antihistamines, raises questions about possible immunoglobulin E-mediated hypersensitivity. The report highlights the need for increased vigilance regarding allergic reactions to new diabetes medications, particularly in the context of GIP/GLP-1 receptor agonists.

Keywords: allergic reaction; gip/glp-1 receptor agonist; hypersensitivity; safety; tirzepatide.

Figure 1. Urticaria on the left hand

Figure 2. Urticaria on the right hand

Figure 3. Urticarial rash presented across the arm