The penetration of ceftazidime into extravascular fluid

Ceftazidime achieved high concentrations in extravascular fluid following intravenal or intramuscular administration to healthy male volunteers. Subcutaneous fluid was sampled using the implanted cotton thread technique. The concentration/time curves of ceftazidime in subcutaneous fluid, after a short distributive phase, were similar in profile to concurrent serum concentrations. The degree of penetration as determined by ratio of the area under curve for subcutaneous fluid levels to the area under curve for the serum levels was 54%. There is evidence from experiments in animals that antibiotic concentration/time profiles in the subcutaneous compartment reflect levels found in rapidly equilibriating tissue fluids or well perfused tissues. It is therefore concluded that ceftazidime will achieve therapeutically useful levels in a wide range of tissues and tissue fluids in man in exess of the MIC90 for Pseudomonas aeruginosa, Staphylococcus aureus and members of the Enterobacteriaceae.