Carbapenems have an overall broad antibacterial spectrum and should be protected against from the acquisition of drug resistance. The clinical advantages of
carbapenem in cases of
pneumonia have not been certified and the need for antipseudomonal
antimicrobial agents to treat
healthcare-associated pneumonia (HCAP) remains controversial. We introduced an antimicrobial stewardship program for
carbapenem and
tazobactam/piperacillin use and investigated the effects of this program on the clinical outcomes of 591
pneumonia cases that did not require intensive care unit management,
mechanical ventilation or treatment with
vasopressor agents [221 patients with community-acquired
pneumonia (CAP) and 370 patients with HCAP]. Compared with the pre-intervention period, age, comorbidities and the severity and etiology of
pneumonia did not differ during the intervention period.
Carbapenems were rarely used during the intervention period in cases of
pneumonia (CAP: 12% vs. 1%, HCAP: 13% vs. 1%), while antipseudomonal
beta-lactam use was reduced from 33% to 8% among cases with HCAP. This reduction in the rate of
carbapenem administration did not have an impact on the prognosis in the cases of CAP, and the in-hospital mortality was lower among the patients with HCAP during the intervention period (15% vs. 5%, p = 0.013). The causes of death in the cases of HCAP were not directly related to
pneumonia during the intervention period. The current study shows that
carbapenem use can be avoided in cases of CAP or HCAP that are not in a critical condition. The frequent use of antipseudomonal
beta-lactams does not improve the clinical outcomes of HCAP.