[A comparative study of tazobactam/piperacillin and piperacillin in bacterial pneumonia]

The efficacy, safety and usefulness of tazobactam/piperacillin (TAZ/PIPC), in bacterial pneumonia and lung abscess were determined with PIPC as the control in a multi-institutional comparative study a penicillin antibiotic for injection prepared by combining a newly developed beta-lactamase inhibitor, tazobactam (TAZ), with a broad spectrum penicillin antibiotic, piperacillin (PIPC), at a ratio of 1:4. TAZ/PIPC was intravenously injected at a dose of 2.5 g (titer) twice a day, and PIPC at a dose of 2.0 g (titer) twice a day as a rule for 14 days. The following results were obtained: 1. The efficacy rates for bacterial pneumonia and lung abscess were 94% (80/85) in TAZ/PIPC group and 89% (70/79) in PIPC group, showing no significant difference between the two groups. 2. In a comparison of degrees of improvement in clinical symptoms, signs and laboratory findings, there were no significant differences between the two groups except for results on thoracic rales after three days of administration. 3. As for bacteriological effects, the elimination rates of causative organisms were 98% (40/41) in the TAZ/PIPC group and 80% (28/35) in the PIPC group. Thus, the TAZ/PIPC group was significantly superior to the PIPC group. The TAZ/PIPC group showed significantly better eradication of bacteria as well. Bacteria considered to be pyogenic were detected in 80 patients (43 administered TAZ/PIPC and 37 administered PIPC), but beta-lactamase production was confirmed in only 11 patients of each group. There were no significant differences in bacteriological effects among these patients. Minimum inhibitory concentrations of TAZ/PIPC against beta-lactamase producing organisms were distinctly superior to those of PIPC. 4. Side effects occurred in 10% (10/96) of the TAZ/PIPC group and 7% (7/95) of the PIPC group. Abnormal clinical laboratory test values were observed in 22% (20/92) of the TAZ/PIPC group and 18% (17/93) of the PIPC group. Thus, there were no significant differences between the two administration groups. 5. The usefulness rate in the TAZ/PIPC group was 87% (75/86) and it was 85% (67/79) in the PIPC group, showing no significant difference between them. The results suggest that TAZ/PIPC administered at a dose of 2.5 g (titer) twice a day is more useful than PIPC administered at a dose of 2.0 g (titer) twice a day in the treatment of bacterial pneumonia.