title: Protease inhibitor-induced urolithiasis.
abstract: OBJECTIVE
  To describe protease inhibitor-induced urinary stone disease in patients with human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS) who are taking indinavir sulfate (Crixivan), a protease inhibitor, for the treatment of AIDS.
  
  
  METHODS
  Patients with HIV/AIDS and symptomatic renal colic temporally related to the initiation of indinavir sulfate therapy were prospectively identified. Seven patients (mean age 42 years; all men) with HIV and renal colic who were taking indinavir were identified. Retrospective chart reviews and patient interviews were performed.
  
  
  RESULTS
  Indinavir therapy averaged 5.7 months prior to presentation with renal colic. All patients had microscopic hematuria. One patient presented with acute azotemia from bilateral urinary obstruction. Six patients had no history of urinary stones prior to initiating indinavir. The median number of symptomatic urinary stone episodes after initiating indinavir was two stones per patient. All patients had moderate- to high-grade urinary obstruction from radiolucent calculi. Abdominal computed tomography (CT) demonstrated hydronephrosis without urinary calcifications. Three patients spontaneously passed stones and 4 required intervention. Yellow debris and/or brown matrix-like material was seen endoscopically. Stone analysis revealed pure protease inhibitor. Six patients (86%) eventually discontinued protease inhibitor therapy.
  
  
  CONCLUSIONS
  Protease inhibitor-induced urinary stones are radiolucent and can cause high-grade ureteral obstruction. Protease inhibitor-induced urinary stones were not identified on unenhanced abdominal CT scans. The radiolucent gelatinous nature of such stones makes lithotripsy a poor choice of treatment. Ureteral stenting may allow spontaneous stone passage if symptomatic obstruction occurs. Urologists may encounter a greater number of patients with symptomatic protease inhibitor-induced urinary calculi as these medications become more popular.
authors.affiliation: Department of Urology, University of California School of Medicine, San Francisco 94143-0738, USA.
authors.forename: D L
authors.initials: DL
authors.lastname: Gentle
authors.forename: M L
authors.initials: ML
authors.lastname: Stoller
authors.forename: T W
authors.initials: TW
authors.lastname: Jarrett
authors.forename: J F
authors.initials: JF
authors.lastname: Ward
authors.forename: K S
authors.initials: KS
authors.lastname: Geib
authors.forename: A F
authors.initials: AF
authors.lastname: Wood
mesh_terms: D000328:Adult; D003085:Colic / Q000139:chemically induced; D015658:HIV Infections / Q000188:drug therapy*; D017320:HIV Protease Inhibitors / Q000009:adverse effects*; D006801:Humans; D019469:Indinavir / Q000009:adverse effects*; D007669:Kidney Calculi / Q000139:chemically induced*; D007674:Kidney Diseases / Q000139:chemically induced; D008297:Male; D011446:Prospective Studies
chemical_list: D017320:HIV Protease Inhibitors; D019469:Indinavir