Laboratory and clinical studies of HBK

Abstract

Laboratory and clinical studies on a new aminoglycoside antibiotic HBK were performed, comparing the results with other aminoglycoside antibiotics. HBK was tested in vitro with respiratory pathogenic organisms, using the agar dilution method to determine the minimum inhibitory concentrations. HBK was more active in vitro against Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae and Enterobacter species than the other broad-spectrum aminoglycoside antibiotics tested, i. e., dibekacin, gentamicin, amikacin and tobramycin; it was less active against Pseudomonas aeruginosa than dibekacin and tobramycin. Synergy of HBK with cefsulodin could be demonstrated against respiratory isolated of Pseudomonas aeruginosa. HBK at a dose of 75 mg was injected intramuscularly into one patient with chronic bronchitis. The peak serum concentration of this patient was 8.09μg/mI, the serum half-life being 109 min. HBK at a dose of 100 mg was infused intravenously over 60 min into one patient with bronchiectasis. The peak serum concentration of this patient was 11.34μg/ml, the serum half-life being 108 min. The intrabranchial secretion level of HBK was 1. 38μg/ml, and the maximum sputum level was 1.15 μg/ml. The ratio of maximum sputum level to peak serum concentration was 10. 1%. After intratracheal injection of HBK 100 mg/saline 2 ml, HBK 50 mg/saline 2ml and HBK 25 mg/saline 2 ml into rabbits, serum concentrations reached peak values within 30 min and were demonstrated the concentration dependence. Twelve patients with respiratory infections were treated with HBK intramuscularly. Clinical responses were excellent in one, good in nine, fair in one and poor in one. A good clinical response was observed in all of two respiratory infections treated with HBK inhalation. Nine patients with respiratory infections were treated with HBK intravenously. Clinical responses were good in six and fair in three. HBK was effective in 83%, 100% and 67% of those cases with intramuscular, inhalant and intravenous administration respectively. The feeling of fullness in the ear was observed in one patient. The data indicate that HBK is one of the most effective and useful broad-spectrum aminoglycoside antibiotics for the treatment of respiratory bacterial infections. © 1986, Japanese Society of Chemotherapy. All rights reserved.