Abstract
Abstract: :
Purpose: Ciprofloxacin is often used in the treatment of endophthalmitis and sometimes used as prophylaxis. However, there is little consensus as to the optimum dose and timing of administration. The purpose of this study was to assess aqueous(aq) humour levels following two alternative dosing regimes. Methods: In this prospective study, patients undergoing routine cataract surgery were allocated into two groups. Group A(30 patients) received 750mg of ciprofloxacin orally as a single dose 1-2 hours prior to surgery and group B (30 patients) received two doses of 750mg ciprofloxacin 12hrs apart with the second dose given 1-2hrs prior to surgery. Aq humour samples were taken following paracentesis and ciprofloxacin levels were measured using a previously validated technique of capillary zone electrophoresis. Patients on medication that potentially had an effect on serum ciprofloxacin levels were excluded. Results: The mean concentration of ciprofloxacin was 0.34 micrograms/ml (range 0.17-0.6) for group A and 0.35 micrograms/ml (range 0.12-0.67)for group B. 33% of patients in group A and 32% of patients in group B had a level of at least 0.4 micrograms/ml, the minimum inhibitory concentration level(MIC90) for Staph Epidermidis (the commonest cause of endophthalmitis). Patients over the age of 75 in both groups achieved higher mean concentrations than those less but still below the 0.4 level required for adequate prophylaxis. Conclusion: Ocular bioavailability of ciprofloxacin was similar in both groups. Oral administration of ciprofloxacin in the above regimes was only effective in just over 30% of patients as a potential prophylactic agent against endophthalmitis. This is in contrast to some previously published data using similar regimes and may be due to differing assaying techniques for ciprofloxacin.
Keywords: 514 pharmacology • 324 aqueous • 398 endophthalmitis