ß-Lactam Antibiotics Frequently Underdosed in Critically Ill Patients

Adequate antibiotic therapy is a key element in the treatment of critically ill patients with severe infections. However, little is known about the actual free antibiotic concentrations achieved by standard dosing, interfering factors, and the clinical consequences of not achieving defined concentration targets. Researchers have now reported the largest study to date on pharmacokinetics of ß-lactam antibiotics in critically ill patients, involving 330 patients with 369 infection episodes (median APACHE II score, 22). At sampling, 14% were on continuous renal replacement therapy and 39% showed augmented renal clearance (ARC; creatinine clearance >130 mL/min). Free serum concentrations of ampicillin, benzylpenicillin, cefazolin, ceftriaxone, …