In this episode, I’ll discuss whether resistance against 1 antipseudomonal beta lactam means the others can’t be used.
The anti-pseudomonal beta-lactams commonly used are ceftazidime, cefepime, meropenem, and piperacillin-tazobactam.
Since the resistance mechanisms are similar between these antibiotics, investigators recently examined whether resistance to 1 or more of these antibiotics affected the odds of mortality and discharge home if another antipseudomonal beta lactam was used for treatment.
Over 550 patients were included in this retrospective cohort study. The authors found that:
Relative to patients with no APBL resistance, patients with resistance to ≥ 1 APBL had a higher 30-day mortality (adjusted odds ratio (aOR) [95% confidence interval (CI)]: 1.65 [1.02-2.66]) and were less likely to be discharged home (adjusted hazard ratio (aHR) [95% CI]: 0.50 [0.29-0.85]).
While the authors admit that further study is needed, these results suggest that resistance to 1 antipseudomonal beta lactam might necessitate a change in antibiotic strategy. If this were to be replicated in a larger or prospective study, practice might change to considering the entire resistance profile of Pseudomonas before selecting treatment. The possibility does exist that the differences in groups could be explained by baseline differences that are inherent in patients with resistant pathogens. Finally, the study was sponsored by a pharmaceutical company that stands to benefit if fewer standard antipseudomonal beta lactam antibiotics are used.
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