Cytotoxicity and uptake of pefloxacin, ciprofloxacin, and ofloxacin in primary cultures of rat hepatocytes.

The cytotoxicity and the uptake of three 4-quinolones--pefloxacin, ciprofloxacin, and ofloxacin--were investigated in primary cultures of rat hepatocytes. As assessed by intracellular enzyme release in culture media, pefloxacin at concentration 400 mg/l and ciprofloxacin at 200 mg/l were found to be hepatotoxins. However, concentration ofloxacin up to 400 mg/l were not hepatotoxic. After 48 h incubation, the remaining antibiotic concentrations in the culture medium as determined by HPLC were 55%, 45%, and 35% for ofloxacin, ciprofloxacin, and pefloxacin, respectively. Comparisons of quinolone concentrations in the hepatocyte culture medium determined by HPLC and correspondent antibacterial activities determined by microbiological assays did not reveal any metabolites with antibacterial activity other than those which have been identified from intact animals.