[Renal lithiasis due to indinavir]

Indinavir sulphate is a protease inhibitor that has been found to be extremely effective in increasing CD4+ cell counts and in decreasing HIV-RNA titers in patients with HIV and AIDS. However, patients receiving indinavir also have been noted to have a significant risk of developing urolithiasis. Indinavir has high urinary excretion with poor solubility in a physiologic pH solution. The typical symptoms of indinavir urolithiasis are similar to other forms of urolithiasis. Indinavir urolithiasis is unique in that computed tomography, which was once thought to be efficacious in identifying all urinary calculi, is not useful in imaging stones that are composed of pure indinavir. Indinavir urolithiasis generally responds to a conservative regimen of hydration, pain control, and temporary discontinuation of the medication. Only a minority of patients need surgical intervention.