VANCOMYCIN LEVELS AFTER INTRAVITREAL INJECTION - EFFECTS OF INFLAMMATION AND SURGERY

Citation
He. Aguilar et al., VANCOMYCIN LEVELS AFTER INTRAVITREAL INJECTION - EFFECTS OF INFLAMMATION AND SURGERY, Retina, 15(5), 1995, pp. 428-432
Citations number
NO
Categorie Soggetti
Ophthalmology
Journal title
RetinaACNP
ISSN journal
0275004X
Volume
15
Issue
5
Year of publication
1995
Pages
428 - 432
Database
ISI
SICI code
0275-004X(1995)15:5<428:VLAII->2.0.ZU;2-W
Abstract
Objective: Vancomycin hydrochloride for intraocular injection is the d rug of choice for the treatment of suspected gram-positive endophthalm itis. To study its intraocular pharmacokinetics, we injected vancomyci n into the vitreous cavity of phakic, aphakic, and aphakic-vitrectomiz ed rabbit eyes and determined its rate of clearance. Inflamed eyes wer e compared to control eyes in each group. Methods: Three groups of eye s were prepared. The eyes in Group 1 were phakic, the eyes in Group 2 had the lens removed, and the eyes in Group 3 had both the lens and ce ntral vitreous removed. Each group was subdivided into a control group and a group made inflamed by injection of heat-killed Staphylococcus epidermidis. Vancomycin hydrochloride 1 mg in 0.1 cc of diluent was in jected into the midvitreous cavity and samples obtained at 2 or 3, 8, 24, and 48 hours after injection. Vancomycin concentrations were measu red and clearance rates were calculated for each of the groups. Result s: Vancomycin was cleared substantially faster from aphakic-vitrectomi zed eyes (half-life 9.0 hours) and aphakic eyes (half-life 8.9 hours) than phakic eyes (half-life 25.1 hours). inflammation increased the ra te of elimination of vancomycin only in the aphakic group. Conclusions : Clearance of vancomycin from the phakic eye is prolonged compared to that of beta-lactam antibiotics, an important pharmacokinetic advanta ge in treating endophthalmitis, its clearance from aphakic-vitrectomiz ed eyes is dramatically faster than from phakic eyes and is similar to that of other antimicrobial agents.