Therapeutic effects of imipenem-cilastatin on experimental intrauterine infections in rats.

The therapeutic effects of imipenem-cilastatin (MK-0787-MK-791) on experimental intrauterine infections in progesterone-treated virgin rats and postpartum rats were studied. The relative efficacy of imipenem-cilastatin for the treatment of such intrauterine infections was compared with that of cefazolin and ampicillin for the treatment of infections caused by Escherichia coli and Streptococcus faecalis, respectively. Treatment with imipenem-cilastatin significantly inhibited the proliferation of E. coli and S. faecalis in uteri, as compared with the proliferation in untreated controls. Cefazolin failed to affect the E. coli infection. With the S. faecalis infection, ampicillin effectively reduced bacterial growth, as compared with that in untreated controls. However, ampicillin was inferior to and comparable to imipenem-cilastatin in progesterone-treated virgin rats and postpartum rats, respectively. A further experiment with S. faecalis infections in rats made neutropenic by intraperitoneal injection of cyclophosphamide showed that the therapeutic effectiveness of imipenem-cilastatin was superior to that of ampicillin and was not influenced by neutropenia. Our results suggest that imipenem-cilastatin may be a useful agent for the treatment of obstetric and gynecologic infections.