Cefpirome and moxifloxacin are drugs which may be used in the empiric therapy of purulent infections. They may be used as monotherapy or they may be combined, e.g. with fosfomycin. Cefpirome is a 4th class cephalosporin with a broad spectrum (gram positive and gram negative pathogens), penetrating well into soft tissues. Moxifloxacin is a new fluoroquinolone with a considerable antimicrobial spectrum, also penetrating excellently into soft tissues. Based on the experiences with the methods and results obtained from our recent study on fosfomycin penetration into abscess fluid, the present pilot study will be set out to gain PK information on the penetration properties of cefpirome and moxifloxacin into abscess fluid and abdominal cysts.