1973 年 21 巻 2 号 p. 421-424
Pharmacokinetic profiles, antibacterial properties and clinical effects of sulfamethoxazole (SMX) -trimethoprim (TMP) combination preparation were studied. Plasma concentrations of SMX as determined by BRATTON MARSHALL method reached a peak in 2 hours in adult patients given a single SMX-TMP combination tablet containing 400 mg SMX and 80 mg TMP : peak values for free SMX averaged 33.3 mcg/ml and that for total SMX averaged 39.3 mcg/ml. Peak plasma values for both free and total SMX were recorded 4 hours after oral ingestion in patients with 2 tablets dose; average free SMX concentration being 54.2 mcg/ml and that of total SMX 60. 0 mcg/ml. Plasma concentrations of TMP assessed by fluorimetry were found to scatter markedly and no uniform correlation was observed between peak plasma levels and hours after drug intake. The excretion of TMP in the urine ranged from 8.6 to 29.1% in the first 6 hours and that of total SMX 7.1-21.0%.
Minimum inhibitory concentrations of SMX-TMP combination mixed at a ratio of 20 : 1 against 42 strains of pathogenic Staphylococci, as determined by agar disc dilution method, ranged 1. 56-0. 045 mcg/ml. This antibacterial activity was stronger by 2 dilution tubes than those of kanamycin and streptomycin.
Fifteen patients mainly consisting of soft part superficial infections due to Staphylococcus aureus were given SMX-TMP combination preparation; 11 patients responded favorably. A mild diarrhea was observed in a single patient and no other untoward reactions have been experienced.