To the Editor With keen interest, we read the retrospective cohort study by Chanderraj et al,1 which investigated the mortality influences posed by different classes of broad-spectrum antibiotics among patients with suspected sepsis, based on data collected during a period of specific antibiotic shortage. Their findings indicated that the use of piperacillin-tazobactam was associated with a significant increase in 90-day mortality and a decrease in organ failure鈥揻ree days compared to cefepime. They suggested that the extended anaerobic coverage provided by piperacillin-tazobactam might be responsible for these outcomes. We agree that this is an important factor; however, we propose that other pharmacokinetic and pharmacodynamic issues related to piperacillin-tazobactam may also contribute to its adverse outcomes.