In vitro antipseudomonal activity of cefsulodin, a new cephalosporin, -Its therapeutic effect on infections episodes of pseudomonas in patients with chronic obstructive pulmonary diseases

The minimum inhibitory concentration (MIC) of cefsulodin against 45 patient strains of Pseudomonas aeruginosa, most of which were isolated from the sputum, ranged from less than 1.56 to 800 μg/ml, and 70 percent of the strains tested were inhibited at concentrations less than 6. 25μg/ml. Against the patient strains of Pseudomonas aeruginosa, cefsulodin was 16-fold more active than SBPC, 8-fold more active than TIPC and 2-fold more active than PIPC, and was 2-fold less active than GM. The minimum bactericidal concentration of cefsulodin, which was needed to kill 70 per cent of 45 patient strains tested (70% MBC), was 12. 5μg/ml and this value was 8 times lower than that of PIPC or TIPC and 16 times lower than that of SBPC, and was 8 times higher than that of GM. Then therapeutic effects of cefsulodin on 6 episodes of Pseudomonas infection in 5 patients with chronic obstructive pulmonary diseases were evaluated. The patients were treated by intravenous drip infusion of 1 to 2 grams of cefsulodin twice a day for 8 to 14 days. Clinical response was excellent in one, good in three, and fair or poor in two patients. Pseudomonas aeruginosa was eradicated from the sputum of 4 patients who showed excellent or good clinical responses, but the bacilli persisted in the sputum from the other 2 patients. No adverse symptom developed and no abnormalities were detected by renal, hepatic and haematological examinations during and in one patient even at the end of administration of a total amount of 56g of cefsulodin.