Nephrolithiasis on indinavir.

(1) Nephrolithiasis is found in 4-13% of patients treated with indinavir, an HIV protease inhibitor. Most of these stones are composed of indinavir. (2) Outcome is often favourable, with simple passage of the stone, but endoscopic or surgical treatment is sometimes required. (3) Crystalluria seems to be more frequent, but is often asymptomatic. (4) Prevention is based on fluid intake of at least 1.5 litres a day. Indinavir withdrawal may be necessary.