Selecting antibiotics based on pharmacokinetic and pharmacodynamic principles

Area of Science:

• Pharmacology
• Infectious Diseases
• Clinical Pharmacy

Background:

• Antimicrobial selection relies on key pharmacokinetic and pharmacodynamic (PK/PD) parameters.
• Area under the curve (AUC) and minimum inhibitory concentration (MIC) are crucial for optimizing drug choice.
• The interplay between antibiotic, pathogen, and host defines treatment efficacy.

Purpose of the Study:

• To explore the PK/PD relationships influencing antimicrobial selection.
• To elucidate the triangular relationship between antibiotic, infecting organism, and patient.
• To demonstrate how PK/PD principles inform novel dosing strategies.

Main Methods:

• Analysis of AUC/MIC ratio, maximum concentration to MIC ratio, and time above MIC.
• Categorization of antibiotic killing mechanisms (concentration-dependent vs. independent).
• Examination of the post-antibiotic effect (PAE).

Main Results:

• Antibiotic pharmacodynamics are defined by AUC/MIC, Cmax/MIC, and %T>MIC.
• Aminoglycosides and fluoroquinolones exhibit concentration-dependent killing.
• Beta-lactams demonstrate concentration-independent killing.

Conclusions:

• PK/PD principles, including PAE, enable optimized antimicrobial dosing.
• Strategies like once-daily aminoglycosides and continuous infusion beta-lactams leverage these principles.
• Understanding these relationships enhances therapeutic effectiveness and combats resistance.