Tissue penetration of meropenem in patients undergoing gynecologic surgery

The purpose of this study was to assess the tissue-penetrating ability of a new β-lactam antibiotic, meropenem, in 64 patients undergoing elective gynecologic surgery. Patients received a single 500-mg dose intravenously before surgery. Plasma and tissue concentrations of meropenem were highest at ~1 hour, and good tissue penetration was seen in the variety of specimens evaluated. The median plasma concentration at ~1 hour was 13.3 μg/mL. The median fluid and tissue concentrations at ~1 hour were as follows: cervix, 8.5 μg/g; endometrium, 2.3 μg/g; fallopian tube, 1.9 μg/g; myometrium, 3.6 μg/g; ovary, 2.3 μg/g; and uterus, 2.3 μg/g. These tissue concentrations exceed the MICs of meropenem for 90% of typical pathogens associated with gynecologic infections. Meropenem readily penetrates gynecologic tissue. A single 500-mg dose provides adequate tissue concentrations for treatment of gynecologic infections caused by susceptible pathogens.