Microbiological basis of antibiotic therapy

Abstract

The parameter used most frequently as a basis for chemotherapy is the minimal inhibitory concentration (MIC). The results of this test are widely influenced by the method applied. A test under in vivo-like conditions is most likely to serve as a basis for rational therapy. The MIC values, measured in different body fluids under varying conditions, also vary, however. Therefore it is unlikely that any measured MIC corresponds with the actual MIC at the site of the infection. The consequence is that a standard test has to be applied which always gives reproducible results. The measured values can thus only to be regarded as relative data in comparison with the concentration of the drug at the site of the infection. Pathogen elimination in vivo during therapy and population-kinetics under the influence of varying concentrations of a drug in vitro are discussed with to the evaluation of the efficacy of different dosages of an antibiotic.

Bactericidal Activity of Cef otiam and Cef tizoxime against <i>Neisseria gonorrhoeae</i> in an in vitro Model Simulating Plasma and Cantharidal Blister Fluid Levels after the Single Intramuscular Application of One Gram

“…During the last years more and more interest has been focussed on its limitations which mainly result from the fact that bacteria in vivo are exposed to continuously changing concentrations of antibiotic depending on its pharmaco kinetics [ Wiedemann, 1980], To simulate the conditions in vivo more closely with respect to the actual levels, several in vitro models have recently been developed. The concentrations intended in vitro range from steadily declining concentrations [Shah, 1980[Shah, , 1981[Shah, , 1983 and step wise changing concentrations [Nishida et al, 1980] to concentrations which actually represent concentrations determined in man at various points of time after appli cation [Grasso et al, 1978;Klaus et al, 1981;Wiedemann and Seeherg, 1984].…”