title: Evaluation of vitreous levels of gatifloxacin after systemic administration in inflamed and non-inflamed eyes.
abstract: OBJECTIVE
  This study aimed to evaluate the human vitreous penetration of gatifloxacin in inflamed and non-inflamed eyes after oral administration.
  
  
  METHODS
  Vitreous penetration of single-dose (400 mg) oral gatifloxacin was evaluated in patients (n = 33) undergoing vitreous tap during the standard procedure for intravitreal antibiotic injection for acute postoperative endophthalmitis at various time-points. Vitreous penetration of 400 mg oral gatifloxacin was evaluated in the non-inflamed eyes of patients (n = 33) undergoing pars plana vitrectomy at similar time-points. The study was extended to evaluate the vitreous penetration of single-dose oral (800 mg) gatifloxacin at a single time-point in inflamed (n = 10) and non-inflamed (n = 11) eyes.
  
  
  RESULTS
  After 400 mg oral gatifloxacin, inflamed eyes showed mean vitreous concentrations of 0.58+/-0.19 microg/ml, 1.33+/-0.33 microg/ml and 1.30 +/- 0.23 microg/ml at 2, 4 and 6 hours, respectively. The levels reached at 2 and 4 hours were found to be significantly increased compared with those in non-inflamed eyes. At the 800-mg dose, 4-hour vitreous levels in inflamed and non-inflamed eyes were 1.57 +/- 0.3 microg/ml and 1.42 +/- 0.24 microg/ml, respectively. Although the increased dose of gatifloxacin elevated plasma concentration, it failed to raise vitreous levels significantly higher than the 400-mg dose at the 4-hour time-point.
  
  
  CONCLUSIONS
  Orally administered gatifloxacin achieves therapeutic levels in both inflamed and non-inflamed human eyes with a spectrum covering the bacterial species most frequently involved in the various causes of endophthalmitis. However, the levels achieved were below the MIC(90) for Pseudomonas aureginosa and Enterococcus.
authors.affiliation: Department of Vitreoretinal Diseases and Trauma, Dr Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India.
authors.lastname: Rajpal
authors.forename: Ambatipudi
authors.initials: A
authors.lastname: Srinivas
authors.forename: Raj Vardhan
authors.initials: RV
authors.lastname: Azad
authors.forename: Yog Raj
authors.initials: YR
authors.lastname: Sharma
authors.forename: Atul
authors.initials: A
authors.lastname: Kumar
authors.forename: Gita
authors.initials: G
authors.lastname: Satpathy
authors.forename: Thirumurthy
authors.initials: T
authors.lastname: Velpandian
mesh_terms: D000284:Administration, Oral; D000890:Anti-Infective Agents / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics*; D004305:Dose-Response Relationship, Drug; D009877:Endophthalmitis / Q000378:metabolism*; D005260:Female; D024841:Fluoroquinolones / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics*; D000077734:Gatifloxacin; D006801:Humans; D008297:Male; D008875:Middle Aged; D009994:Osmolar Concentration; D013997:Time Factors; D014822:Vitreous Body / Q000378:metabolism*
chemical_list: D000890:Anti-Infective Agents; D024841:Fluoroquinolones; D000077734:Gatifloxacin