title: Efavirenz-induced urolithiasis.
abstract: We describe the first case of efavirenz-induced urolithiasis in a 47-year-old HIV-positive patient. Urinary obstruction led to pyelonephritis and septic shock, requiring emergency ureteral catheterisation. The subsequent clinical course was favourable, allowing the patient's discharge on day 5. A 7 mm, radio-translucent, non-crystalline, beige stone was extracted during catheterisation. Stone analysis by Fourier transform infrared spectrometry, liquid chromatography and mass spectrometry revealed a stone composed of efavirenz (EFV) metabolites M4, M5, M8 (as described by Mutlib et al. in 1999) and approximately 50% of unspecified proteins. EFV is a non-nucleoside reverse transcriptase inhibitor introduced to European markets in 1999. It is principally metabolised by cytochrome P450 3A4 and 2B6. Of the dose, 14-34% is excreted in the urine, 1% as unchanged drug. The patient had been taking 600 mg EFV per day for 3 years. As EFV-induced urolithiasis has not been reported so far, we would like to draw the attention of the medical community to this potentially severe complication.
authors.affiliation: Division of Urology, Department of Surgery, University Hospital of Geneva, Geneva, Switzerland. jgwirth@yahoo.com
authors.forename: G J
authors.initials: GJ
authors.lastname: Wirth
authors.forename: J
authors.initials: J
authors.lastname: Teuscher
authors.forename: J D
authors.initials: JD
authors.lastname: Graf
authors.forename: C E
authors.initials: CE
authors.lastname: Iselin
mesh_terms: D000480:Alkynes; D019380:Anti-HIV Agents / Q000009:adverse effects* / Q000378:metabolism; D048588:Benzoxazines; D003521:Cyclopropanes; D006801:Humans; D008297:Male; D008875:Middle Aged; D010078:Oxazines / Q000009:adverse effects* / Q000378:metabolism; D011704:Pyelonephritis / Q000209:etiology; D014545:Urinary Calculi / Q000139:chemically induced* / Q000737:chemistry / Q000150:complications
chemical_list: D000480:Alkynes; D019380:Anti-HIV Agents; D048588:Benzoxazines; D003521:Cyclopropanes; D010078:Oxazines; C098320:efavirenz