Purpose: To evaluate the time course of drug concentrations achieved in aqueous (AQ), vitreous (V), and serum (S) compartments after oral administration of linezolid and levofloxacin.
Design: Randomized, clinical trial.
Settings: Clinical practice.
Patient population: Sixteen patients (16 eyes) undergoing vitrectomy who had not had a prior pars plana vitrectomy in the study eye were randomly assigned to one of 4 groups.
Intervention: AQ, V, and S samples were obtained from all subjects after single concomitant doses of linezolid 600 mg and levofloxacin 750 mg between 1 and 12 h before the procedure: group A = 1-3 h; group B = 3-6 h; group C = 6-9 h; group D = 9-12 h.
Main outcome measures: AQ, V, and S concentrations of linezolid and levofloxacin.
Results: Overall mean concentrations ± standard deviation (μg/mL) achieved by linezolid in AQ, V, and S compartments were 3.32 ± 2.06, 2.98 ± 1.87, and 7.91 ± 3.94, respectively. Overall mean concentrations ±standard deviation (μg/mL) achieved by levofloxacin in AQ, V, and S compartments were 2.19 ± 1.92, 1.95 ± 1.27, and 7.38 ± 3.47, respectively.
Conclusions: Single concomitant doses of linezolid and levofloxacin achieved AQ and V concentrations above the minimum inhibitory concentration for 90% of common ocular gram-positive and gram-negative pathogens up to 12 h after administration. The combination of linezolid and levofloxacin represents a viable option for the prophylaxis and management of endophthalmitis.