[What is the importance of bacterial eradication in the treatment of respiratory tract infections?].

During the last few years, increasing antibiotic resistance amongst the major respiratory pathogens in the community has compromised the choice of empirical therapy for some respiratory tract infections. Of special interest has been the progressive increase in the resistance rates of Streptococcus pneumoniae to macrolides and penicillin, and of S. pyogenes to macrolides. Several studies have confirmed the association between community use of certain antibiotics and the development of resistance in S. pneumoniae and S. pyogenes. Nevertheless, not all the antibiotics have the same ability to select resistance and not all microorganisms are affected in the same way. The aim of antimicrobial therapy in respiratory tract infections is bacterial eradication. Pharmacokinetic and pharmacodynamics can be used to predict bacteriological eradication with antimicrobial therapy.