Acute tubulointerstitial nephritis following treatment with exenatide.

BACKGROUND: Acute tubulointerstitial nephritis, a cause of acute kidney injury, is seen occasionally following treatment with medications such as antibiotics and non-steroidal anti-inflammatory drugs. To date, the development of biopsy-proven acute tubulointerstitial nephritis after treatment with exenatide has not been reported. CASE REPORT: A 58-year-old man was prescribed exenatide for poorly controlled Type 2 diabetes mellitus. He subsequently developed deterioration in kidney function, with the estimated glomerular filtration rate declining from 59 to 39 ml min(-1) 1.73 m(-2) over 2 months. Despite cessation of exenatide, there was continued deterioration in estimated glomerular filtration rate to 16 ml min(-1) 1.73 m(-2). He underwent renal biopsy and the sections showed active diffuse tubulointerstitial nephritis with infiltration of eosinophils. He was treated with prednisolone over several months with incomplete recovery in kidney function. CONCLUSION: Acute tubulointerstitial nephritis should be suspected if there is deterioration in kidney function in a patient treated with exenatide in the absence of other causes of acute kidney injury such as dehydration or hypotension.