Evaluation of gatifloxacin for its potential to induce antioxidant imbalance and retinopathy in rabbits.

Gatifloxacin, a fluoroquinolone antibiotic, has been reported to produce several adverse reactions. In the present investigation, gatifloxacin administered at the dose rate of 10 and 20 mg kg(-1) body weight per day, respectively, for 21 consecutive days, was evaluated for its potential to induce antioxidant status alterations and retinal damage in rabbits. A significant alteration in the antioxidant status of rabbits particularly in the high-dose group was observed which is indicated by decreased activity of superoxide dismutase and levels of blood glutathione with a concomitant increase in the activity of catalase, glutathione peroxidase, and glutathione S-transferase enzymes. The activity of glutathione reductase differed nonsignificantly between groups throughout the study period. The levels of malondialdehyde were elevated in the high-dose group. The histopathological examination of eyeball tunics revealed clumping of nuclei of the retinal outer nuclear layer in the gatifloxacin-treated groups. The results from this study indicate that repeated gatifloxacin administration produces a dose-dependent oxidative stress and retinopathy.