[Interstitial nephritis attributed to treatment with piperacillin-tazobactam and with ciprofloxacin].

A 26-year-old man was treated with piperacillin-tazobactam because of suspected cholangitis and a 77-year-old man was given ciprofloxacin because of an infected knee-prosthesis. They both developed symptoms of an interstitial nephritis: malaise and laboratory deviations. The symptoms disappeared after the antibiotics were withdrawn. No other explanation for the renal function disorders could be found in either patient. Piperacillin-tazobactam and ciprofloxacin are considered to be relatively safe and serious adverse effects are rare. Acute interstitial nephritis may, however, occur and its clinical presentation may not be very informative. Withdrawal of the culprit usually leads to recovery.