Abstract
Physical Compatibility of Ertapenem and Meropenem in 0.45% Normal Saline and Plasma-Lyte A
Author(s): Brown Berah, Schemmel Jacquelyn, Reinert Justin P, Baki Gabriella, Howard Mitchell S, Churchwell Mariann D
Issue: Sep/Oct 2025 - Volume 29, Number 5
Page(s): 430-434
Abstract
Background: Intravenous medications and fluids must be compatible to ensure patient safety and optimal clinical outcomes. The physical compatibility of ertapenem and meropenem has not been conclusively established in 0.45% sodium chloride and Plasma-Lyte A. Methods: An in vitro analysis of the physical compatibility of ertapenem and meropenem at 10 mg/mL and 20 mg/mL concentrations was conducted in 0.45% sodium chloride and Plasma-Lyte A over 24 hours. Admixtures were prepared in triplicate at hours 0, 1, 5, 8, and 24 and were visually inspected, underwent spectrophotometric testing, and pH analysis. Results: All ertapenem admixtures were found to be physically compatible over 24 hours. Meropenem 10 mg/mL had demonstrable changes in pH and was found to be physically incompatible beyond 8 hours in 0.45% sodium chloride and Plasma-Lyte A. Meropenem 20 mg/mL was found to be physically incompatible beyond 5 hours when mixed in 0.45% sodium chloride. Conclusions: Our results are the first that have demonstrated physical compatibility for ertapenem 10 mg/mL and 20 mg/mL in 0.45% sodium chloride and Plasma-Lyte A. The findings of this meropenem analysis confirm a previous report that evaluated simulated Y-site samples at 1 hour but expanded upon those findings to show physical compatibility at 8 hours and 5 hours for the 10 mg/mL in both fluids and 20 mg/mL in 0.45% sodium chloride concentrations, respectively. Previously published reports of the stability of meropenem indicating a concentration and temperature-dependent are confirmed by this analysis. Chemical stability studies should be undertaken to support these results.