Endocrine Abstracts

Background: Incretin-based therapy is increasingly used in the management of type 2 diabetes mellitus. Although dipeptidyl peptidase-4 inhibitors (gliptins) are well tolerated, side effects can be observed in various body systems. Here we report three cases of drug-induced skin eruption with strong itching of the gliptins plus metformin combination therapy.

Case reports: A 59-year-old woman and a 57-year-old man, who had been using vildagliptin plus metformin for 2 and 6 months respectively admitted to our institution with allergic skin lesions. A 61-year-old man with type diabetes who had been using sitagliptin plus metformin for 3 months, admitted to our institution. Their physical examination indicated good general condition, with no pathological findings except for the skin eruptions. Skin lesions appeared on their chest, abdomen, arms, and legs that hyperemic, erratic, erupted, and pruritic. Patients had no history or evidence of autoimmune, neoplastic, or infectious diseases. The combined treatment was discontinued in patients. Patient 1 switched to metformin plus nateglinide, patient 2, and 3 to metformin plus gliklazid. After withdrawal of the gliptin plus metformin combination, there was a significant improvement of eruption. None of the patients treated with prednisolone. Complete remission was achieved 8, 10, and 7 weeks after discontinuation of gliptin plus metformin respectively.

Conclusion: Skin lesions in patients went into remission despite further metformin administration. We suggest that in our patients development of allergic reaction of skin was due to gliptin alone. Although skin eruption due to gliptin is rare, it is a considerable complication. Despite its unknown mechanism, this reaction should be considered in patients using gliptin. More observation is required over a period of time to clarify use of this class of drug.