URINARY CALCULI AND CRYSTALLURIA IN HIV+ PATIENTS TREATED WITH INDINAVIR SULFATE

OBJECTIVES: Anti-proteases, a new class of Anti-HIV drugs used in comb ination with reverse transcriptase inhibitors have led to spectacular improvement in the patients' clinical status. Since April 1996, indina vir is the most widely prescribed anti-protease in France. PATIENTS AN D METHODS: From July 1996 to July 1997, we analyzed 46 spontaneously e xpulsed stones in 45 HIV+ patients (35 men and 10 women; age range 25 to 64 years) given indinavir in combination viith other drugs since on e week to ten months. Only six patients were known to have a past hist ory of renal lithiasis. RESULTS: Forty-one calculi contained indinavir monohydrate (INDM) identified by mass spectrometry and infrared spect rophotometry. INDM was the only component excepting proteins in 39/45 calculi. in the 12 others, other compounds were also identified. Among the 114 urine samples collected 2 to 3 hours after an 800 mg dose of indinavir, 38 (33%) monohydrate indinavir crystals, identified by infr ared microscopy. Mean urinary pH was significantly higher than in samp les without INDM crystals (6.53 +/- 0.68 versus 5.96 +/- 0.71, p < 0.0 01). CONCLUSION: Two measures could possibly reduce the risk of crysta lization: administration of urine acidifiers and increased fluid intak e to raise diuresis. Alkalinisation is not indicated. Long-term increa sed fluid intake should be prefered over acidification which could be reserved solely for the treatment of drug-induced lithiasis.