Aqueous and vitreous penetration of levofloxacin after oral administration

Objective: To investigate the penetration of levofloxacin, an optical S-(-) isomer of ofloxacin, into the aqueous and vitreous humor after oral adminis tration, Design: Randomized, clinical trial comparing tissue levels of levofloxacin after one or two doses 12 hours apart, Participants: Forty-five patients undergoing initial vitrectomy between Feb ruary 1997 and June 1997 at the UIC Eye Center. Methods: Aqueous, vitreous, and serum samples were obtained and later analy zed from 45 patients after oral administration of 1 500-mg tablet (group 1, 22 patients) or 2 500-mg tablets (group 2, 23 patients) 12 hours apart bef ore surgery. Main Outcome Measures: Aqueous, vitreous, and serum concentrations of levof loxacin (micrograms/ milliliter). Results: Group 1 achieved mean aqueous, vitreous, and serum levels of 0.59 +/- 0.48 mu g/ml, 0.32 +/- 0.34 mu g/ml, and 4.34 +/- 3.59 mu g/ml, respect ively. Group 2 achieved mean aqueous, vitreous, and serum levels of 1.90 +/ - 0.97 mu g/ml, 2.39 +/- 0.70 mu g/ml, and 8.02 +/- 3.14 mu g/ml. Conclusions: Mean inhibitory aqueous and vitreous MIG,, levels were achieve d against a majority of ocular pathogens, including Staphylococcus aureus a nd Staphylococcus epidermidis, Streptococcus pneumoniae (vitreous), Bacillu s cereus (vitreous), Haemophilus influenzae, Moraxella catarrhalis, and mos t gram-negative aerobic organisms except Pseudomonas aeruginosa after two d oses given 12 hours apart, Mean MIG,, levels were obtained in the vitreous for a majority of pathogens responsible for traumatic, postoperative, or bl eb-related endophthalmitis.