Purchase this article with an account.
J Schauersberger, W Jager; In-vitro Investigation of the Protein Binding of Different Antibiotics in the Human Vitreous . Invest. Ophthalmol. Vis. Sci. 2002;43(13):1853.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: Penetration of different antibiotics into the human vitreous has been intensively investigated within the last years. Total vitreous concentrations in addition with MIC90 values were used to determine the antimicrobial activity of the respective drugs. Recent scientific findings about pharmacokinetics (PK) and pharmacodynamics (PD) of anti-infective drugs in body tissues reveal the low sensitivity of this method. Important factors like the intravitreal protein binding have not been taken into account, even though the common doctrine is, that only protein unbound drugs are able to achieve a pharmacological effect. In consideration of this fact we made this trail to investigate the protein binding of five different antibiotics in the human vitreous. Methods: After harvesting vitreous from donor eyes, six vitreous samples, for each of the three different drug concentrations of each antibiotic type, were spiked for this study. After an ultrafiltration procedure, the unbound vitreous concentrations of meropenem, moxifloxacine, levofloxacine and vancomycin were determined by reversed-phase HPLC. Unbound fosfomycin concentrations were measured using an established gas chromatographic spectrometric analysis method. Results: With respect to the different concentrations, the range of the not protein bound fraction in the levofloxacine group was between 95 - 99%; meropenem group 16 - 27%; moxifloxacine group 36 - 82%; and vancomycin group 58 - 89%. Fosfomycin concentrations will be presented. Conclusion: Sufficient antimicrobial therapy can only be obtained by understanding the complex interactions between the host, the infected tissue, the infecting agent and the administered drug. Looking at one part of these interactions the results of our study indicate, that the evaluation of the protein binding of antibiotics in the vitreous is essential to determine their local antimicrobial activity. Further systematic investigations of PK and PD parameters and interactions can potentially result in substantial savings of time and expenses and may help to avoid innumerable clinical studies.
This PDF is available to Subscribers Only