Basic and clinical studies on tazobactam/piperacillin in respiratory infections

We performed basic and clinical studies on tazobactam/piperacillin (TAZ/PIPC), a new formulation of the β-lactamase inhibitor tazobactam (TAZ) and piperacillin (PIPC), and thefollowing results were obtained. 1. Antimicrobial activity: The minimum inhibitory concentrations (MIC) of TAZ/PIPC against a total of 257 clinically isolated strains of 12 species were measured and compared with those of PIPC, clavulanic acid/ticarcillin (CVA/TIPC), cefotiam (CTM) and cefoperazone (CPZ), using the MIC2000 System (Dynatech Laboratories). TAZ/PIPC showed stronger bactericidal activity than PIPC and CVA/TIPC, and much stronger activity than CTM or CPZ against gram-positive bacteria, but CPZ showed much stronger activity than TAZ/PIPC against gram-negative bacteria. 2. Clinical study results: TAZ/PIPC (5 g per day) was given to three patients with pneumonia and one with acute bronchitis, for 4~15 days. Clinical response was excellent in two patients and good in two patients. Mild fever was observed in one patient. Abnormal laboratory findings were observed in one patient with eosinophilia and elevation of GPT, but these were transient. From the above results, we consider TAZ/PIPC to be a useful antibiotic for the treatment of respiratory tract infection.