Azlocillin and mezlocillin concentration in human prostatic tissue.

The concentrations of azlocillin and mezlocillin in human prostatic tissue obtained by transurethral resection or enucleation were measured after two 2.0-gram doses of either drug. The average plasma concentration of azlocillin and mezlocillin at time of tissue sampling was 64.9 and 36.3 micrograms/ml, respectively, and tissue concentration at the time of sampling was 22.9 micrograms/g for azlocillin and 9.4 micrograms/g for mezlocillin. The plasma/tissue concentration ratio for mezlocillin was 0.25 and for azlocillin 0.35. Concentrations of mezlocillin in tissue obtained by transurethral resection were similar to those obtained by enucleation. Azlocillin and mezlocillin in appropriate doses achieve a concentration in human prostatic tissue above the inhibitory concentration for common bacterial pathogens.