1984 Volume 32 Issue Supplement9 Pages 163-174
The antibacterial activity of AC-1370, a new cephem antibiotic, was tested against each 27 clinical isolates of 7 species, using plate dilution method with inoculum size of 106 cells/ml. The peak concentrations of AC-1370 in MIC distributions were obtained at 12.5-50 Agiml for S. aureus, 6.3 for E. coli, 3.1 for K. pneumoniae, 1.6 for P. mirabilis, and >100 for Serratia sp. The above mentioned activity was inferior to that of every reference drug; CTM, CMZ, CTX and LMOX. The peak concentrations of AC-1370 for P. morganii and P. aeruginosa were 12.5 and 12.5μg/ml respectively, which were almost same as those of CTX and LMOX.
Pharmacokinetics of AC-1370 were investigated in 6 healthy male volunteers. Intravenous administration of the drug at a dose of 0.5 g or 1.0 g yielded that mean plasma levels measured by bioassay method were 56.9μg/ml at a dose of 0.5 g and 120.3μg/ml at a dose of 1.0 g after 5 minutes, respectively, after 1 hour, 17.1 and 38.2 and after 4 hours, 3.8 and 8.9μg/ml. The β-phase biological half-lives of the drug were estimated to be 1.92 and 1.74 hours, respectively. The urinary excretion rates within 8 hours were 81.0% at a dose of 0.5 g, and 86.4% at a dose of 1.0g, respectively.
Twenty four patients with bacterial infections were treated with AC-1370 at a daily dose of 2 g twice a day by intravenous drip infusion. The clinical response to the treatment was excellent in 16 cases, good in 3 cases, fair in 3 cases, poor in 1 case and unevaluable in 1 case. The effectiveness rate was calculated as 82.6% (19 cases out of evaluable 23 cases).
As side effects, eruption occurred in one patient, and eosinophilia was observed in one patient.
