Abstract
Purpose::
To investigate the penetration of moxifloxacin (Schering-Plough), a fourth-generation fluoroquinolone, into the vitreous humor after oral administration.
Methods::
A prospective, non-randomized clinical trial in which 32 consecutive patients (age 27 - 83, mean 62.4 ± 11.8 years) scheduled for elective pars plana vitrectomy were assigned to one of four dosing groups: Control (n = 3), which received no medication; Single-dose (n = 11), which received one 400 mg oral dose of moxifloxacin 3 hours before surgery; 2-dose (n = 8), which received one 400 mg dose approximately 14 hours before surgery and a second 400 mg dose 3 hours before surgery; and 5-dose (n = 10), which received one 400 mg dose on each of the 4 days preceding surgery and a fifth dose 3 hours before surgery. Demographic data, including gender, race, surgical indication, diabetic status, phakic status, and history of prior vitrectomy, were collected and did not differ significantly between groups. Undiluted vitreous samples were obtained from all 32 patients and analyzed using high-performance liquid chromatography.
Results::
Intravitreal moxifloxacin concentrations (mean ± SD) were as follows: Control, below quantifiable levels; Single-dose, 572.091 ± 238.85 ng/µL; 2-dose, 1561.25 ± 340.40 ng/µL; 5-dose, 1200.40 ± 645.13 ng/µL. Concentration differences between the Single-dose and 5-dose groups (p = 0.007) and between the Single-dose and 2-dose groups (p = 0.0001) were statistically significant. Concentration differences between the 2-dose and 5-dose groups (p = 0.17) were not statistically significant.
Conclusions::
Orally-administered moxifloxacin achieves significant levels in the non-inflamed human vitreous. Administering 2 or 5 doses of oral moxifloxacin prior to surgery leads to similar intravitreal concentrations and is superior to single-dose administration, though all 3 groups attained levels exceeding the minimum inhibitory concentrations of many bacteria implicated in postoperative endophthalmitis (including S. epidermidis). These data support further evaluation of single or two-dose oral moxifloxacin for prophylaxis against endophthalmitis. Multiple daily doses of oral moxifloxacin may serve as a useful adjunct in its treatment.
Keywords: endophthalmitis • antibiotics/antifungals/antiparasitics