Question: Nephrolithiasis is a known complication associated with treatment of HIV using the protease inhibitor indinavir sulfate. What unique factor often makes the diagnosis of nephrolithiasis secondary to Indinavir difficult?
Answer: The cited reference notes: “The detection of Indinavir [related stones] itself poses another challenge as no single imaging modality proves superior in definitively diagnosing indinavir stones. One study found that no abdominal imaging study is diagnostic, intravenous pyelogram detects less than 8% of indinavir stones, renal ultrasounds demonstrated obstruction in 82% of cases, and CT imaging revealed obstruction with no stones in over 50% of the cases.” (Huynh J et al. Indinavir-induced nephrolithiasis three and one half years after cessation of Indinavir therapy. 2011 Int Urol Nephrol 43:571-573 and Nadler RB,et al. The etiology of urolithiasis in HIV infected patients. 2003 Am Urolog Assoc 169:475–477).