[Pharmacokinetic and pharmacodynamic aspects of interpretive reading of the antibiogram].

The interpretative reading of the antimicrobial susceptibility test is mainly based on microbiological and pharmacodynamic data. Microbiological information splits bacterial strains into those having antimicrobial resistance mechanisms and that do not. With this information, and using the pharmacokinetic parameters of each antimicrobial it is possible to make pharmacodynamic approaches to predict antibiotic success or failure in an infectious process. Many studies have emphasized the usefulness of three pharmacodynamic indexes associated with therapeutic success: rate maximum concentration/MIC (C(max)/MIC), area under de curve /MIC (AUC/MIC) ratio, and time to concentration excess MIC (T>(MIC)). The Monte Carlo simulation enables the susceptibility breakpoint to be calculated for each antibiotic-microorganism, trying to achieve its target with a probability greater than 90%. Clinical data should confirm the susceptibility breakpoints or, if not, these breakpoints should be to be reconsidered.