Costs, CDI Risk Lower With Extended- vs Standard-Infusion Piperacillin-Tazobactam

Extended-infusion piperacillin-tazobactam (TZP) is associated with decreased rates of incident Clostridioides difficile infection (CDI) and mortality compared with standard-infusion TZP, according to findings of a retrospective cohort study published in Infectious Medicine.

Patients (N=3398) who received standard (n=1364) or extended (n=2034) infusions of TZP at Unity Health Toronto in Canada between 2009 and 2015 were included in this analysis. The primary outcome was 14-day in-hospital mortality; secondary outcomes included incident CDI, length of hospitalization, readmission at 30 days, and nursing- and pharmacy-related costs ($CAD). The protocol for standard infusion TZP was a 30-minute 3.375-g or 4.5-g intravenous (IV) infusion every 4 to 6 hours or every 6 to 8 hours, respectively. The protocol for extended-infusion TZP was a 4-hour 3.375-g or 4.5-g IV infusion every 8 (weight, >120 kg) or 12 (creatinine clearance, <20 mL/min) hours, respectively. Researchers analyzed primary and secondary outcomes via logistic regression and linear logistic regressions models.

Among patients who received extended vs standard infusions, the mean (SD) age was 70.44 (16.92) and 69.29 (16.90) years, 57.0% and 57.5% were men, 13.7% and 20.4% were admitted to an intensive care unit (ICU) at TZP initiation (P <.001), and 3.1% and 6.4% tested positive for Pseudomonas aeruginosa (P <.001), respectively.

Receipt of extended- vs standard-infusion TZP was associated with lower rates of 14-day mortality (17.3% vs 21.5%; P =.002) and incident CDI (3.0% vs 5.7%; P <.001), as well as decreased length of hospitalization (median, 10.00 vs 11.00 days; P <.001). No significant between-group differences were observed in regard to the rate of 30-day readmission (5.5% vs 6.7%; P =.183).

Further analysis showed that extended vs standard infusions were significantly associated with lower total (median, $9514.00 vs $11,409.50; P <.001) and nursing-related (median, $8016.50 vs $9665.00; P <.001) costs. Of note, pharmacy-related costs alone did not significantly differ between the interventions (median, $1149.00 vs $1285.50; P =.827).

Factors significantly associated with increased 14-day mortality risk included ICU admission (odds ratio [OR], 2.79; 95% CI, 2.23-2.51; P =.001), older age (OR, 1.59; 95% CI, 1.49-1.71; P <.001), and higher Charlson comorbidity index score (OR, 1.16; 95% CI, 1.11-1.21; P <.001) at TZP initiation. Female sex (OR, 0.80; 95% CI, 0.67-0.97; P =.021) and receipt of extended-infusion TZP (OR, 0.76; 95% CI, 0.63-0.91; P =.003) were significantly associated with decreased 14-day mortality risk.

In the final adjusted analysis, receipt of extended- vs standard-infusion TZP was associated with decreased CDI incidence (adjusted OR [aOR], 0.59; 95% CI, 0.41-0.84; P =.003) and lower health care-associated costs (aOR, 0.92; 95% CI, 0.87-0.98; P =.006).

Limitations of this study include the retrospective design and potentially insufficient data.

According to the researchers, “[O]ur study showed extended infusion piperacillin/tazobactam to be associated with a lower risk of 14-day mortality, lower incidence of C. difficile infections and lower costs.”