Seventy five patients with
respiratory infections, including 40 cases of acute
pneumonia, 33 cases of
secondary infection after chronic
pulmonary diseases and 2 cases of
pulmonary abscess, were treated with
cefotetan (CTT, Yamatetan) by
drip infusion in order to evaluate its clinical efficacy. The overall rate of effectiveness was 83.8%. CTT was examined comparatively with other
beta-lactam antibiotics for antibacterial activity on clinically isolated strains of 3 major respiratory pathogens including Haemophilus influenzae, Branhamella catarrhalis and Streptococcus pneumoniae. Minimum inhibitory concentrations (MIC's) of CTT on H. influenzae were less than 3.13 micrograms/ml regardless of the production of
beta-lactamase by these organisms. As to B. catarrhalis, CTT also exerted an antibacterial activity enough to control the proliferation of all the strains at a level of 1.56 micrograms/ml. Against S. pneumoniae, on the other hand, CTT exhibited the lowest activity of all the drugs tested but still showed MIC's of 3.13 micrograms/ml or less.
Drip infusion of CTT at a dose of 2 g brought about an average maximum blood concentration of 342 +/- 25.7 micrograms/ml and an average half-life in blood of 2.48 +/- 0.41 hours Maximum sputum concentration of the
drug, however, was variable among the cases tested, ranging from 0.40 to 1.80 micrograms/ml. Side effects of the
drug were observed in 5 cases or 6.7%. Four of them had some allergic symptoms; i.e.,
pyrexia and eruption. One patient was especially diagnosed as possible
drug-induced
interstitial pneumonia during the treatment with the
drug. The diagnosis was confirmed by transbronchial lung biopsy and lymphocyte blastogenesis by CTT in vitro. As to abnormal laboratory findings, blood
transaminases were elevated during
drug administration in 13 cases or 17.3%, but were reduced back to the normal level after the withdrawal of the
drug.