Abstract
Objective—To compare penetration of IV administered marbofloxacin in intraocular fluids of healthy and inflamed eyes in rabbits with endotoxin-induced endophthalmitis.
Animals—35 pigmented rabbits.
Procedures—Endophthalmitis was induced in the right eye via intravitreal administration of Escherichia coli endotoxin. The left eye was a control eye. After 24 hours, a single dose of marbofloxacin (4 mg/kg, IV) was administered. Groups of rabbits (n = 5/group) were euthanized 0.5, 1, 2, 4, 6, 10, and 18 hours later, and blood and ocular fluids were collected. Marbofloxacin concentrations were determined via reverse-phase high-performance liquid chromatography, and pharmacokinetic analysis of the data was performed with a mono-compartmental model.
Results—Mean area under the aqueous concentration-time curve was significantly lower in control eyes (1.64 ± 0.07 μg•h/mL) than in inflamed eyes (3.31 ± 0.11 μg•h/mL). Similarly, drug penetration into aqueous humor was 33% and 65% for control eyes and inflamed eyes, respectively. Mean area under the vitreous humor concentration-time curve for control eyes(1.75 ± 0.05 μg•h/mL) was significantly less than for inflamed eyes (2.39 ± 0.16 μg•h/mL). In the vitreous humor, corresponding penetrations were 34% and 47%, respectively.
Conclusions and Clinical Relevance—Penetration of marbofloxacin into the aqueous and vitreous humor after IV administration was significantly enhanced by intraocular inflammation, suggesting a role for this antimicrobial in the prophylaxis or treatment of bacterial endophthalmitis caused by susceptible pathogens.
