Optimal loading dose of meropenem before continuous infusion in critically ill patients: a simulation study

Area of Science:

• Pharmacokinetics and Pharmacodynamics
• Critical Care Medicine
• Infectious Diseases

Background:

• Meropenem is a broad-spectrum antibiotic essential for treating severe bacterial infections.
• Optimizing meropenem dosing in critically ill patients is challenging due to altered physiology.
• Establishing appropriate loading doses is key to achieving therapeutic drug concentrations rapidly.

Purpose of the Study:

• To determine the optimal loading dose of meropenem prior to continuous infusion in critically ill patients.
• To evaluate the impact of patient-specific covariates on meropenem dosing requirements.
• To ensure therapeutic drug concentrations against Pseudomonas aeruginosa, based on EUCAST breakpoints.

Main Methods:

• Utilized a validated pharmacokinetic model for stochastic simulations of virtual critically ill patients.
• Simulated various maintenance doses (1.5-6 g/24h) with preceding loading doses (0.15-2 g).
• Analyzed the influence of covariates (albumin, body weight, creatinine clearance) and simulated best-case/worst-case scenarios.

Main Results:

• Low albumin, high body weight, and high creatinine clearance necessitate increased meropenem loading doses.
• A 0.33 g loading dose achieved adequate concentrations with one extreme covariate.
• A 0.5 g loading dose was required in the worst-case scenario (all three covariates extreme).

Conclusions:

• A meropenem loading dose of 0.5 g administered over 30 minutes is recommended for critically ill patients.
• This loading dose should be immediately followed by a continuous infusion.
• This regimen ensures attainment of target drug concentrations, optimizing treatment efficacy.