 Appropriate empiric antibiotic therapy is crucial for reducing mortality in septic patients. Pathophysiological changes associated with the septic process, i.e. changes in volume of distribution Vd, protein binding and drug clearance Cl, lead to pharmacokinetic PK alterations that may influence the efficacy of the drug. As a consequence, antibiotic plasma concentrations are variable and hard to predict in this patient population. Optimal dosing and exposure can therefore be a challenge and standard antibiotic dosing regimens may result in subtherapeutic concentrations and therapeutic failure. Appropriate dosing is also essential in order to maximize bacterial killing and minimize development of antimicrobial resistance. 