Microdialysis - A novel tool for clinical studies of anti-infective agents

In vivo microdialysis (MD) is an innovative clinical technique that has bee n employed in preclinical research and metabolic studies in patients for mo re than a decade. Recently, MD has been adopted for human drug studies and has opened up the opportunity to quantify tissue drug distribution in vivo. The particular advantage of MD for the anti-infective field relates to the fact that MD allows for online measurement of the unbound, pharmacological ly active drug fraction in the interstitial space fluid (ISF), the anatomic ally defined target site for most bacterial infections. The aim of this rev iew is to provide an overview of the current literature about MD in anti-mi crobial drug studies. It will be shown that MD has become feasible in most human tissues including brain and lung. So far, several MD studies have dem onstrated that anti-microbial concentrations at the effect site may be subi nhibitory, although effective concentrations are attained in serum, a findi ng that has significant impact on clinical decision making. In addition to its property as a pharmacokinetic sampling technique, MD offers unique oppo rtunities in pharmacokinetic-pharmacodynamic (PK-PD) research and has the p otential to streamline the decision process on proper drug dosing in drug d evelopment.