Objective To measure the aqueous humor
concentrations in human eyes after one or two grams of ceftriaxone administered intravenously.Methods
150 patients(150 eyes) with cataract were divided randomly into 1 g dose and 2 g dose groups of 75 each.Each group was further divided into 5 subgroups of 15 each, consisting of 4 sub groups undergoing sampling of aqueous humor 30,60,120, and 180 minutes after administration of drug, and another 1 subgroup as control. About 200 - 300 μl of aqueous humor were taken just before intraocular operations , and the aqueous humor was analyzed by reversed phase high pressure liquid chromatography. Results After one gram of ceferiaxone was administered intravenously,the
concentrations of ceftriaxone in aqueous humor were 0.235 ± 0.121 mg/L,0.474 ± 0.224 mg/L,0.453 ± 0.162 mg/L,and 0.534±0.202 mg/L at the time points of 30,60,120,and 180 minutes
respectively. After two gram dose was administered, the concentrations of ceftriaxone were 0.611 ± 0.141 mg/L, 1.285 ±0.386 mg/L, 1.305 ± 0.310 mg/L,and 1.356 ± 0.365 mg/L at the time points of 30,60,120,and 180 minutes respectively.The average concentrations of ceftriaxone in aqueous humor were 0.424 ±0.210 mg/L and 1.202 ± 0.301 mg/L in 1 g group and 2 g group, respectively. There was significant differences between the two groups ( P <0.01) .Within group comparisions showed that the concentrations of drug in the 30 min. subgroup was lower than those in the other 3 subgroups ( P < 0.01). There were no significant differences in drug concentration between the 60,120,and 180 min subgroups. ( P > 0.05) .The concentrations of ceftrixone in aqueous humor were above the minimum inhibitory concentration for 50% (MIC50) of ceftriaxone for most pathogenic bacteria. Conclusions Ceftriaxone is an effective antibiotic for prophylactic use in internal ophthalmic surgery and also for the treatment of intraocular infections due to susceptible microorganisms.