Objective: To investigate the penetration of cefepime (a fourth generation cephalosporin) into the aqueous humor after single-dose intravenous administration in humans.
Patients and methods: Before receiving cataract surgery, 30 patients received randomly 1 g (group 1, 15 patients) and 2 g (group 2, 15 patients) single intravenous injection of cefepime before surgery. Samples of aqueous humor and serum were obtained at 0.5, 1, 2, 4, and 12 hours after injection. Three patients were sampled each time for 1 g and 2 g of cefepime. Samples were assayed for cefepime concentrations with high performance liquid chromatography (HPLC).
Results: All the patients had detectable cefepime in their aqueous humor and serum measurable by HPLC. A mean peak aqueous humor level was 5.16 +/- 0.88 microg/mL in group 1 and 5.87 +/- 1.64 microg/mL in group 2 at 0.5 hour after injection. The mean level of cefepime in aqueous humor decreased after 0.5-hour measurements in both groups and was measured as 0.82 +/- 0.21 microg/mL in group 1 and 2.04 +/- 0.30 microg/mL in group 2 at 12 hours after injection.
Conclusion: Aqueous humor levels of cefepime after single IV injection were above the minimum inhibitory concentration (MIC90) for most ocular pathogens, but the duration of exposure to an antibiotic was not sufficient for therapeutic effect.