[Pharmacokinetic studies on the penetration of azlocillin and mezlocillin into bone and tissue fluid (author's transl)].

During and after hip replacement arthroplasty antimicrobial concentrations in serum, bone and tissue-fluid were determined microbiologically using agar diffusion assay technique after 15-min infusion of 5 g 6-[D-2-(2-oxoimidazolidine-1-carboxamido)-2-phenylacetamido] - penicillanic acid (azlocillin) and 5 g 6-[D-2-(3-methylsulfonyl-2-oxoimidazolin-1-ylcarboxamido)-2-phenylacetamido]-penicillanic acid (mezlocillin) and after i.v. bolus injection of 2 g mezlocillin. Serum pharmacokinetic data on the individual patients are computer derived using a modified open two-compartment model. The geometric mean of bone level determinations at defined intervals with deviation factor are presented. These results are related to the organic bone compartment and are expressed in mg/l. From the tissue fluid-concentration curve, peak concentration CP and its time were calculated. The time for which one-fourth of the peak concentration CP 1/4 was maintained in tissue fluid was determined graphically. This concentration is compared with the cumulative minimum inhibitory concentrations of representative bacteria causing bone and joint infections. These results are focused as criteria of valuation of antimicrobial chemotherapy.