A case of exercise-induced acute renal failure in a patient with idiopathic renal hypouricemia developed during antihypertensive therapy with losartan and trichlormethiazide.

Exercise-induced acute renal failure (ARF) developed in a 45-year-old man during antihypertensive therapy with losartan and trichlormethiazide. The antihypertensive therapy was stopped and marked hypouricemia became apparent during improvement of his renal function. The daily urinary excretion of uric acid was normal and an increased fractional excretion of uric acid was observed. Renal biopsy revealed that the kidney was recovering from acute tubular necrosis with interstitial fibrosis. Based on the results of pyrazinamide and benzbromarone tests, we classified this case as one of presecretory reabsorption defect of uric acid. Antihypertesive therapy with benidipine and candesartan was initiated, and the patient has not had any ARF episodes since. Because idiopathic renal hypouricemia can be associated with exercise-induced ARF and chronic renal dysfunction, careful antihypertensive therapy and follow-up evaluation of renal function might be necessary for hypertensive patients with idiopathic renal hypouricemia.