LABORATORY AND CLINICAL STUDIES ON TA-058

Abstract

Laboratory and clinical studies on TA-058, a new penicillin, were carried out and resluts were as follows.
1) Antibacterial activity
Minimal inhibitory concentrations (MIC) of TA-058 for 272 strains isolated from various clinical materials (S. aureus 27, E. coli 27, K. aerogenes 27, E. cloacae 27, P. mirabilis 27, P. vulgaris 27, S. marcescens 27, P. aeruginosa 27, H. influenzae 56) were determined and compared with those of amoxicillin (AMPC). MIC of TA-058 against E. coli, E. cloacae, P. mirabilis and H. infiuenzae were 1-2 times higher than those of AMPC in general. On the other hand, MIC of TA-058 against S. aureus was 1-2 times lower than those of AMPC. Against the other organism, MICs of TA-058 were equal to those of AMPC.
2) Serum levels and sputum levels
In three patients with chronic respiratory infection, TA-058 was administrated by intravenous drip infusion. Peak serum levels were 44.5-67.5 pgiml at a dose of 1 g. The level ranged from 1.7-4.6μg/ml at five hours. Peak sputum levels of TA-058 were 4. 0-6.6μg/ml, but in one case peak sputum level was only 0.17μg/ml.
3) Clinical results and side effect Fourteen patients with respiratory tract infections (acute pneumonia 7, chronic bronchitis 4, lung abscess 2, bronchiectasis 1) were treated with TA-058 by intravenous drip infusion. Eight of the fourteen patients responded satisfactorily to the treament and the efficacy rate was 57.1%(8/14)(excellent 2, good 6, poor 3, not evaluable 3). No side effect and abnormality in laboratory findings were observed in any cases.