Sulfamethoxazole-Trimethoprim 合剤の小児科領域における基礎的・臨床的検討

抄録

1. In vitro antimicrobial activities of sulfamethoxazole (SMX) -trimethoprim (TMP), alone and in combination, were studied in Staphylococcus and Escherichia coli strains isolated from pediatric patients. Potentiation of activities was demonstrated by combinations of SMX and TMP against both SMX-resistant and sensitive strains. The minimal inhibitory concentrations of SMX-TMP combination against SMX-resistant strains were found to be higher than those presumed to be attainable in vivo. The bactericidal activities of SMX-TMP combination, although significantly superior to those of either drug alone, were thought to be moderate. It was also found that the bactericidal effect of TMP was more marked in strains resistant to SMX rather than in those originally sensitive to the sulfonamide.
2. A new bioassay method for SMX and TMP applicable in pediatric patients was proposed. Determination of antimicrobial activities in serum and urine from an 8-year-old patient indicated somewhat lower values than those expected from previous reports. Whether this discrepancy was due to the difference in methods applied or patients' age remains to be studied.
3. SMX-TMP combination product was given to a pediatric patient with pyelonephritis caused by Klebsiella (MIC : SMX>800 mcg/ml, TMP>0. 78 mcg/ml), who had shown resistance to various chemotherapeutic agents including chloramphenicol, tetracycline, ampicillin, kanamycin and nalidixic acid. Changes in urine bacterial counts were followed while concentrations of SMX and TMP were also determined. Bacteriuria was cleared in 24 hours and no recurrence ensued 2 weeks' treatment with the combination preparation.