Indinavir crystalluria: identification of patients at increased risk of developing nephrotoxicity.

OBJECTIVE

To determine whether the protease inhibitor indinavir sulfate, which is extremely insoluble at physiologic pH levels and which is known to be associated with nephrolithiasis, is associated with crystalluria at a usual therapeutic dose.

METHODS

Freshly voided urine from 27 male human immunodeficiency virus patients being treated with indinavir at a dose of 800 mg, tid, in an outpatient setting and from 20 healthy subjects undergoing routine physical examination was subjected to dipstick urinalysis and microscopic examination of urinary sediments.

RESULTS

Three (11%) of 27 patients treated with indinavir developed highly characteristic crystalluria during the course of therapy. No such crystals were observed in the urine of the 20 healthy subjects.

CONCLUSION

Indinavir crystalluria was identified in asymptomatic patients treated with usual therapeutic doses of the drug. Screening urines of patients taking indinavir may be useful in identifying patients at risk for developing nephrotoxicity.