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Intraocular Penetration of Orally and Intravenously Administered Fluoroquinolones in Non-Inflamed Eyes of the Patients Undergoing Vitrectomy Surgery
Nihar Ranjan Biswas Nihar Ranjan Biswas, Alok Kumar Ravi, Thirumurthy Velpandian, Raju S, Sat Pal Garg, Supriyo Ghose
India

Purpose: This study evaluated intraocular penetration of fluoroquinolones (FQs) viz, ofloxacin, pefloxacin, lomefloxacin and sparfloxacin in aqueous, vitreous humours, and plasma after oral/intravenous administration in the subjects undergoing vitrectomy.

Methods: Ofloxacin, pefloxacin, lomefloxacin and sparfloxacin were included for oral administration. Only ofloxacin and pefloxacin included for intravenous study. Each group was sub-divided in 3 time points (3, 6 and 12hrs post dose). For each time point, 8 eyes (8 patients) were included and a total of 144 patients enrolled in this study. Intra-operatively, 80-110µl aqueous, 100-250µl vitreous and 2ml of venous blood samples were collected. Plasma separated and all samples were stored at -70^oC and subjected for quantification using HPLC and compared with their known MIC₉₀ of common ocular pathogens.

Results: In oral 400mg single dose, among all 4 FQs, ofloxacin showed a maximum concentration at 3 hours in aqueous (0.98±0.33±g/ml) and vitreous (0.78±0.35µg/ml). Intravenous infusion of 400mg ofloxacin also showed the similar levels in humors of the eye at 3 hours. Despite low plasma levels, lomefloxacin showed higher aqueous to plasma (a/p) and vitreous to plasma (v/p) ratio.

Conclusion: FQs 400mg (as iv and oral) as a single dose could not reach the desired therapeutic concentration (above MIC₉₀ for all ocular pathogens) in aqueous and vitreous humour. The concentration reached in the humors may not be totally dependent on their plasma levels. More non-polar FQs such as lomefloxacin and sparfloxacin showed better a/p and v/p ratios as compared to their more polar analogs such as pefloxacin and ofloxacin.