The First Successful Desensitization Protocol in Exenatide Allergy: A Case Report

Abstract Background: Glucagon-like peptide-1 (GLP-1) receptor agonists are important treatment options in obese patients with type 2 diabetes. To date, few immediate allergic reactions due to GLP1 analogues were reported. One report revealed that a patient with an immediate hypersensitivity reaction due to exenatide was able to tolerate liraglutide, the alternative GLP-1 receptor agonist. Since exenatide is the only available GLP-1 receptor agonist covered by insurance in our country, a drug desensitization protocol, the only therapeutic method in hypersensitivity reactions used in case of absence of an alternative drug, was considered. Here we report a successful desensitization protocol for the first time in two obese diabetic patients with an immediate hypersensitivity to exenatide. Case presentation: The first patient was a 47-year-old female. She was referred to our outpatient allergy clinic because of a generalized urticaria developed within minutes in the first week of an exenatide BID 5 mcg/20 mcl treatment. The second patient was a 46-year-old female. She had a large local immediate injection site reaction appeared in 15 minutes following an exenatide BID 5 mcg/20 mcl injection for a month. We applied desensitization with exenatide to two patients who need GLP-1 receptor agonist treatment. Protocol was completed in 7 steps in approximately 3 hours, with the aim of reaching the daily dosage of exenatide. Throughout this process, we observed that both cases tolerated the protocol without any complaints or complications. Conclusions: We present the first successful desensitization protocol to exenatide in both local and/or systemic immediate hypersensitivity reactions and indicate the importance of desensitization in patients who do not have alternative therapies.