Comparative costs of ertapenem and piperacillin–tazobactam in the treatment of diabetic foot infections

Abstract

To evaluate potential cost savings, trial data were used to determine the clinical outcomes for i.v. ertapenem given once daily and i.v. piperacillin-tazobactam given every six hours daily in treating diabetic foot infections. A cost-minimization analysis (CMA) was conducted on the drug-dosing data of the subset of patients enrolled in a recent double-blind randomized trial who were treated solely as inpatients and were clinically evaluable at fi nal assessment (n = 99). Cost per dose was calculated from (a) average hospital acquisition price per dose for ertapenem ($40.52) or piperacillin-tazobactam ($13.58), (b) average U.S. wages and benefits for labor, based on nine published time-and-motion studies of i.v. antibiotic preparation and administration ($3.10), and (c) consumable supplies, using a 40% discount off the manufacturer list price ($2.90). For each patient, the actual number of antibiotic doses given was multiplied by total cost per dose. There were no significant differences between antibiotic groups with respect to patient demographics, percentage with a severe wound, and mean days of i.v. therapy. Compared with piperacillin-tazobactam, patients treated with ertapenem received significantly fewer mean doses (25.5 versus 7.5; p < 0.0001) and lower antibiotic-related costs ($502.76 versus $355.55, respectively; p < 0.001). The $147.21 difference between groups accounts for approximately 3% of total hospital Medicare reimbursements for these infections. A CMA of treatment of diabetic foot infections showed that, compared with piperacillin-tazobactam given four times daily i.v., ertapenem given once daily i.v. was associated with lower drug acquisition and supply costs and less time and labor devoted to preparation and administration of i.v. therapy.