Bacteriological and Clinical Evaluations of Imipenem/Cilastatin Sodium in Neonates and Premature Infants

The antimicrobial activity of imipenem against group B streptococci was investigated. The clinical efficacy of imipenem/cilastatin sodium (IPM/CS) was determined in neonates and premature infants. The results are summarized below. 1. The distribution of MIC values of IPM against 55 clinical isolates of group B streptococci isolated from the vagina of pregnant women peaked at 0.024 μ g/ml. MIC values of IPM against all clinical isolates tested were 0.05 μ g/ml or less. 2. IPM/CS was used for treatment of bacterial infections in 9 neonates and premature infants. Among these patients, clinical responses were excellent in 5 patients and good in 4 patients. No adverse reaction was observed. Abnormal laboratory test values were observed in 4 patients, eosinophilia in 2 patients and increased platelets in 2. 3. In 7 neonates and premature infants, quantitative cultures for aerobic and anaerobic fecal flora were performed. Fecal flora change was not significantly different than those observed during treatment with latamoxef or cefmenoxime. 4. Ten neonates and premature infants were investigated for effects of IPM/CS on the blood coagulation system. Prolongations of prothrombin time (PT) and activated partial throm boplastin time (APTT) were observed in 1 patient. Abnormal prothrombin (PIVKA II) was detected in the same patient. There was no tendency for inhibition of platelet function.