We report two patients treated with ciprofloxacin who presented with a
cute renal failure. On renal biopsy, a necrotizing vasculitis was iden
tified in addition to acute interstitial nephritis. Improvement in ren
al function resulted with the discontinuation of the antibiotic and th
e institution of immunosuppressive therapy. (C) 1995 by the National K
idney Foundation, Inc.