In vitro activity for ZERBAXA® (ceftolozane and tazobactam)
ZERBAXA demonstrated potent in vitro activity
- The clinical significance of in vitro data is unknown.
- Limitations of the SMART data include: lack of clinical information to confirm nosocomial versus community-acquired isolates, relatively small number of isolates tested each year (n=250 per site), small number of sites, and change of sites participating in SMART study over time.1
- Culture and susceptibility information and local epidemiology should be considered in modifying antibacterial therapy.
- ZERBAXA is not active against bacteria that produce serine carbapenemases (K. pneumoniae carbapenemase [KPC]), and metallo-beta-lactamases.
Susceptibility rates for select ICU respiratory tract isolates in U.S. surveillance data (2023-2024)1,a
aIsolates were collected as part of the Study for Monitoring Antimicrobial Resistance Trends (SMART 2023-2024).1
Study design1
The Study for Monitoring Antimicrobial Resistance Trends (SMART) represents the commitment of Merck to monitor the in vitro susceptibility of clinical bacterial Gram-negative isolates to antimicrobials in intra-abdominal (since 2002), urinary tract (since 2009), respiratory tract (since 2015), and bloodstream infections (since 2019). SMART was initiated in 2002 and is a global study. This report specifically focuses on isolates from respiratory tract infections (RTIs), collected from 2023 and 2024.
Minimum inhibitory concentration (MIC) values for ceftolozane/tazobactam and comparator agents were determined using the broth microdilution methodology recommended by the Clinical and Laboratory Standards Institute (CLSI) that was current in the year the data was collected. The following breakpoints were used to test for the susceptibility of P. aeruginosa for ZERBAXA (MICs [mcg/mL]): ≤4/4 (susceptible).
Reference
- Data available on request from the Merck National Service Center via email at daprequests@merck.com. Please specify information package US-ZER-02083.