Antibiotic use in the critical care unit.

The antimicrobial management of patients in the critical care unit is complex. Not only must the clinician be familiar with a number of clinical, microbiological, pharmacological, and epidemiological observations but also fundamental pharmacodynamic concepts. It is an understanding of these concepts that forms the basis for the design of dosing strategies that maximize clinical efficacy and minimize toxicity. Antimicrobial selection is further complicated by the plethora of new antimicrobial agents available with varying clinical utility. Nowhere is this more evident than in the quinolone class of antibiotics. To aid the clinician in differentiating between quinolones it now seems reasonable to create a classification system akin to the generation grouping applied to the cephalosporins. Our classification is based upon the pharmacodynamic principles discussed within this article.