Laboratory and clinical studies on AC-1370 to the patients with respiratory tract infections

Laboratory and clinical studies on AC-1370, a newly developed cephalosporin antibiotic, were carried out with the following results. 1) Antibacterial activity: The minimum inhibitory concentrations (MICs) of AC-1370 was determined against 341 clinical isolates consisted of 11 different species and compared with those of cefmetazole (CMZ), cefazolin (CEZ) and cefoperazone (CPZ). Antibacterial activity of AC-1370 against S. aureus, S. faecalis, E. coli and K. aerogenes were less potent than those of CEZ, CMZ and CPZ, but that against P. aeruginosa and H. influenzae was superior to those of CEZ and CMZ and ranked next to CPZ. 2) Absorption and excretion: AC-1370 was administered to four patients with chronic respiratory tract infections at a dose of 1 gram or 2 gram by intravenous drip infusion for one hour. The peak serum levels were 58.0 ± 2.31 μg/ml with the dose of 1 gram and 92.0 μg/ml with the dose of 2 gram at the termination of infusion. The peak sputum levels were 1.85 – 4.6 μg/ml at two or four hours after. Urinary recovery rates at six hours after at a dose of 1 gram were 65.8 ~ 75% (71.1 ± 8.43%). 3) Clinical results: AC-1370 was given to 59 patients with various respiratory tract infections. That clinical results were excellent in 15, good in 33, fair in 5 and poor in 4 patients. The over all clinical efficacy rate was 84.2%. Bacteriologically, all strains of S. pneumoniae and H. influenzae were eliminated and the elimination rate of P. aeruginosa was good. The over all bacteriological efficacy rate was 83.8%. Total 12 patients showed the following adverse reactions; eruption in 3, eosinophilia in 1, liver disfunction in 6, mild elevation of BUN, and Creatinine in 2 patients.