Overview of toxicological studies.

Ofloxacin was tested in various toxicological test systems. In common with other 4-quinolone derivatives, ofloxacin caused erosions and eruption of blisters in articular cartilage of immature animals. Such effects have not occurred in adults, and monkeys have tolerated ofloxacin up to 40 mg/kg/day for up to 12 months. Administration of various doses of ofloxacin to rats, dogs and monkeys for 4 weeks or up to 12 months did not cause anaemia. Ofloxacin did not impair male fertility. Pefloxacin, in contrast, caused azoospermia and testicular damage in dogs, and enoxacin caused testicular atrophy in rats and reduced spermatogenesis in dogs. In tests for cataractogenesis, ofloxacin was inactive, and adverse hepatic and renal effects occurred only after doses which were greater than the equivalent therapeutic maximum. Mutagenicity studies were negative. Only a recently conducted unscheduled deoxyribonucleic acid synthesis (UDS) test showed some effects, again at therapeutically non-significant concentrations.