Pharmacokinetics and pharmacodynamics, implications in the more rational usage of antimicrobials in pediatrics

Abstract

Pharmaco dynamics describes the complex interrelation established between the antimicrobial and in vitro susceptibility of the bacteria. The clinical and microbiologic efficacy of the antimicrobial can be predicted using three pharmacodynamic parameters, (1) maximal concentration/minimal inhibitory concentration (C max /MIC); area under the plasmatic concentration curve/time against minimal inhibitory concentration (AUC/MIC); (3) duration of doses interval antimicrobial concentration surpasses the minimal inhibitory concentration (T>MIC). The particular kind of antimicrobial determines what parameter is the one that better predicts its efficacy. Currently antimicrobial usage is still discouraging empirical, especially with respect to doses interval and antimicrobial therapy length. As long as it could take decades for new agents against multiresistant pathogens being available in the therapeutic arsenal, knowledge and application of pharmacokinetic and pharmacodynamic principles is the best option to optimize the usage of the old and new antimicrobials, allowing to identify parameters of exposition to drugs, tightly associated to the capability to destroy microorganisms and suppressing the emergency of resistance in subpopulations of organisms.