Effects of antimicrobial drugs on human neutrophil-microbe interactions

Antimicrobial drugs may influence neutrophil-microbe interactions in several ways, and, conversely, neutrophils may interfere with the action(s) of antimicrobial drugs. Here, evidence for the existence of such effects is evaluated and attention drawn to the problems of in vitro experimentation in this area. The review is restricted to those studies that used human neutrophils, clinically achievable drug concentrations, and were well designed. Even so, it is noted that little attempt has been made to investigate underlying mechanisms. The effects of drugs on microbes, which influence neutrophil-microbe interactions, such as concentration and the post-antibiotic effect, are considered. The penetration of antimicrobial drugs into neutrophils and subsequent intracellular activity is discussed and contrasted with observations obtained using macrophages. Overall, neutrophil-microbe interactions are complex and difficult to dissect, and carefully designed experiments using closely defined conditions are required if meaningful results are to be obtained.