Purpose: Indinavir was approved by the Food and Drug Administration in 1996 as a human immunodeficiency type 1 protease inhibitor to treat human immunodeficiency virus infection. Prompted by the high number of patients receiving indinavir who present with renal colic at our institution, we performed a detailed investigation of the true frequency of urolithiasis during indinavir treatment.
Materials and methods: We evaluated 105 patients with a mean age of 38.1 years who were treated with indinavir from 1996 to 1997. Before indinavir treatment was initiated all patients underwent renal ultrasonography, urinalysis, and determination of serum sodium, potassium, calcium, uric acid and creatinine. It was recommended that all patients drink 2 l of fluids daily, and all remained under continuous surveillance.
Results: Metabolic evaluation and ultrasonography showed no abnormality in any case. A stone episode occurred in 13 men (12.4%) as renal colic during observation. Colic recurred in 1 patient after 2 and 5 months, and in 1 after 2 months. Median duration of indinavir treatment until an acute stone episode was 21.5 weeks (range 6 to 50). A total of 12 stones passed spontaneously. Three patients underwent ureteroscopic calculous removal and 1 was treated with extracorporeal shock wave lithotripsy.
Conclusions: Despite adequate patient information and compliance the rate of nephrolithiasis during indinavir therapy was 12.4%.