K-3514. Outcomes of Extended Infusion Piperacillin/Tazobactam for Documented Gram-Negative Infections
Session: Poster Session: Pseudomonas and Other Gram Negatives
Monday, October 27, 2008: 12:00 AM
Room: Hall C
Background: Extended-infusion (EI) of piperacillin/tazobactam (PT) dosing (3.375gm infused over a 4 h period q8h) has been utilized because of its more favorable PD profile over traditional intermittent (TI) PT dosing schemes, especially for MIC values at the high end of the susceptibility range (MIC > 16 mg/L). The objective of this study was to compare clinical outcomes in patients with documented Gram-negative infections among those receiving TI-PT versus EI-PT administration at a community hospital. Methods: A retrospective cohort study was conducted at the Medical Center of Plano (Dallas, TX) from 4/06-3/07. The medical center protocol converted to EI-PT in 10/06. Patients in the TI-PT group were selected from those admitted during the 6 months preceding the protocol change (4/06 - 9/06); these patients received PT 3.375 - 4.5 g q6 - 8h via 30-min infusion. Subjects in the EI-PT group were administered PT 3.375 g q8h via a 4-h infusion during the 6 months following the protocol change (10/06 - 4/07). Subjects included in the analysis were(1) ≥ 18 yrs, (2) non-neutropenic, (3) Gram negative pathogen infection, (4) administered PT within the first 72 h of infection, (5) survived >24 hours, and (6) administered PT ≥ 48 h duration. Demographics, length of stay, comorbid conditions, antibiotic history, microbiologic data and treatment outcomes were collected. Results: Inclusion criteria were met by 81 patients. Baseline characteristics were similar. There were no significant differences in treatment outcomes. Conclusions: EI-PT is an effective alternative dosing strategy to TI-PT dosing. At Medical Center of Plano, the use of EI-PT represents an annual savings of ~40% ($95,000) in drug acquisition costs per year.
Comparison of Clinical Characteristics and Outcomes between PT groups
TI N= 40EI N=41P-value
30 Day Mortality2
Length of Stay in days (range)
Length of Stay (LOS), days7
Overall LOS (n=81)7 (4-11)5 (4-11)0.4
LOS, MIC ≤ 8 mg/L (n = 28)7
LOS, MIC >8-16 mg/L (n = 52)5
LOS, MIC > 64 mg/L (n = 1)NANANA
Asma Lat, PharmD, Medical Center of Plano, Gita Patel, PharmD, Medical Center of Plano, Plano, TX, Nimish Patel, PharmD, Albany College of Pharmacy and Health Sciences, Albany, NY, Thomas Lodise, PharmD, Albany College of Pharmacy, Albany, NY and  G. W. Patel, None.