Classification of betalactam antibiotics according to their pharmacodynamics

Considerable information on the pharmacodynamics of betalactams has accumulated throughout the past 20 years demonstrating a time-dependent killing and some pharmacodynamic differences in the type of activity in-vitro and in animal models that should have clinical significance. Unfortunately few clinical studies have directly examined the effects of different dosages that might be predicted to result in failure or success of the outcome, particularly in serious sepsis. Thus on the basis of a long preclinical and clinical experience we propose a pharmacodynamic classification of betalactam antibiotics. Three classes are delineated by the extent of PBP pattern saturation, biomass increase, PAE length and initial killing power.