Abstract
Labcratory and clinical studies on a new aminoglycoside antibiotic KW-1070 (fortimicin) were performed, comparing the results with other aminoglycoside antibiotics (GM, AMK, TOB, KM).
The antimicrobial activities of these drugs were examined against several respiratory pathogenic organisms. The peak value of KW-1070 against Serratia marcescens was about twice that of the other aminoglycoside antibiotics. However, the antimicrobial activities of KW-1070 against Klebsiella pneumoniae, E. coli, Enterobacter, Proteus, and Pseudomonas aeruginosa were almost the same as those of the other aminoglycoside antibiotics. The peak value of KW-1070 against Pseudomonas aeruginosa was only about half that of the other aminoglycoside antibiotics.
When 50mg/kg intramuscular injections of KW-1070 were administered to rats, the tissue concentration attained the peak fifteen minutes after administration. The concentration was highest in the serum (200μg/ml), followed in descending order by the kidney, lung and liver at their peak. High level concentration in the kidney remained even four hours after administration.
When 200mg of KW-1070 were given to young women with pyelonephritis, the serum peak level was reached thirty minutes after administration (16.8μg/ml). And when 200mg intramuscular injections were administered to a patient with chronic bronchitis, the highest peak level of bronchial secretion was 10.4μg/ml two hours after administration, and the sputum peak level was 1.68μg/ml at the same time.
In the clinical study, KW-1070 was effective in 93%(13/14 cases) of the cases of respiratory infection.
Side effects of this drug were not observed in any of the cases. KW-1070 was evaluated to be very effective and safe, compared with the aminoglycoside antibiotics already in wide use.
