Urolithiasis associated with indinavir in a patient with spinal cord injury

To report a case of indinavir-induced urolithiasis, and the greater risk of this occurrence in individuals with spinal cord injury (SCI) who require fluid restriction for an intermittent catheterization program (ICP).

Case report.

A 38-year-old man with a T4 ASIA A SCI (according to the American Spinal Injury Association classification scale) and human immunodeficiency virus (HIV) infection was using an ICP and taking indinavir (a protease inhibitor) as part of his antiviral regimen. Cystoscopy was performed to rule out recurrent urethral condylomata. He was found to have a bladder stone measuring 0.5 cm x 0.5 cm x 0.3 cm, which, on analysis, was composed of indinavir (100% exterior, 90% interior). The bladder stone was removed under direct visualization. The plain abdominal radiograph did not reveal any stones.

Indinavir is a frequently used drug for the treatment of HIV that has the potential to induce urinary lithiasis. This is particularly problematic for individuals with SCI who are on fluid restriction and an ICP. Therefore, cystoscopy and monitoring for indinavir-induced urolithiasis should be undertaken in individuals with SCI who are taking indinavir. Considerations include switching to a different protease inhibitor or choosing an entirely new HIV drug cocktail with less potential for urolithiasis.