J Investig Allergol Clin Immunol 2011; Vol. 21(3): 245-247 © 2011 Esmon Publicidad CASE REPORTS Hypersensitivity to Repaglinide P Rojas, L Sánchez, A Sant os, MP Gómez, H Blanco, JJ Laguna Allergy Unit, Hospital Central de la Cruz Roja, Madrid, Spain ■ Abstract Meglitinides (repaglinide and nateglinide) are insulin secretagogues used to treat diabetes mellitus. We present a case of hypersensitivity reaction to repaglinide in a 61-year-old man who developed a maculopapular rash 5 days after treatment. Skin prick tests including repaglinide (0.5 μg/mL) and patch tests (0.05% in pet and saline) were performed, and the results were negative. A blind oral challenge test with repaglinide was performed and the therapeutic dose was subsequently taken at home every 24 hours for 7 days. The result was positive with a delayed reaction at day 3. A punch biopsy of the skin lesions revealed drug-induced exanthema. The clinical manifestations, the latency period, the reappearance of cutaneous lesions after rechallenge, and the histopathology report of the skin biopsy suggest a type IV mechanism. Key words: Oral antidiabetic drugs. Exanthema. Meglitinides. Repaglinide. Introduction Changes in lifestyle that promote obesity and physical inactivity have led to a global increase in the prevalence of diabetes, especially type 2 diabetes mellitus (T2DM), which is one of the most challenging health problems in the 21st century. Several studies suggest that the diabetes epidemic will continue, even if levels of obesity remain constant. The prevalence of diabetes for all age groups worldwide is estimated to reach 4.4% by 2030 [1]. New therapeutic approaches in T2DM have emerged in the last 50 years [2]. The American Diabetes Association (ADA) and the European Association for the study of Diabetes (EASD) ■ Resumen Meglitinidas (repaglinida y nateglinida) son antidiabéticos orales del grupo de los secretores de insulina aprobados para el tratamiento de la Diabetes Mellitus (DM). Presentamos un caso de hipersensibilidad a repaglinida en un varón de 61 años de edad, que desarrolló un rash máculo-papular 5 días después de iniciar tratamiento con este fármaco. El estudio alergológico incluyó pruebas cutáneas en prick test con repaglinida (0.5 mgs/ml) y pruebas epicutáneas en parche (0.05%) con repaglinida en vaselina y suero fi siológico. Todas las pruebas cutáneas fueron negativas. Así mismo realizamos pruebas de provocación con repaglinida y posterior tratamiento domiciliario cada 24 horas por 7 días. El resultado fue positivo con una reacción tardía al tercer día. La biopsia cutánea de las lesiones fue diagnóstica de exantema medicamentoso. Las manifestaciones clínicas, el tiempo de latencia, la reaparición de las lesiones tras la reprovocación y los cambios histopatológicos de la biopsia cutánea sugieren un mecanismo de hipersensibilidad tipo IV. Palabras clave: Antidiabéticos orales. Exantema. Meglitinidas. Repaglinida. consensus in 2006 and in subsequent updates propose a new therapeutic algorithm [3]. Repaglinide, which is a member of a new class of insulin secretagogues, the meglitinides (also including nateglinide), was approved for clinical use in 1997. Repaglinide is a carbamoylmethyl benzoic acid derivative and nateglinide a derivative of phenylalanine. Repaglinide is absorbed rapidly, metabolized by the liver, and eliminated mainly in bile. It is licensed for use as monotherapy in patients whose diabetes is not controlled by diet and exercise, or in combination with metformin in those patients whose disease is inadequately controlled with metformin in monotherapy [4]. Repaglinide is safe, although there have been reports of