Intravegetation antimicrobial distribution in aortic endocarditis analyzed by computer-generated model. Implications...

Area of Science:

• Pharmacology
• Infectious Diseases
• Computational Biology

Background:

• Antibiotic penetration into cardiac vegetations is crucial for treating infective endocarditis but remains poorly understood.
• Aminoglycosides are vital in endocarditis therapy, yet their distribution within valvular tissues is not well characterized.

Purpose of the Study:

• To characterize aminoglycoside distribution within aortic vegetations using integrative computer modeling.
• To evaluate the impact of standard versus high-dose amikacin regimens on drug levels within experimental vegetations.
• To simulate aminoglycoside penetration in human aortic vegetations based on rabbit endocarditis data.

Main Methods:

• Integrative computer modeling utilizing pharmacokinetic data from experimental endocarditis.
• Calculation of drug distribution in various geographic sectors of aortic vegetations in rabbits and simulated human models.
• Comparison of drug concentrations against minimum bactericidal concentrations (MBC) in plasma and vegetation.

Main Results:

• Standard amikacin regimens achieved sub-minimum bactericidal concentration (sub-MBC) levels in the center of rabbit vegetations, despite supra-MBC levels in plasma.
• High-dose amikacin (40 mg/kg) achieved supra-MBC levels throughout rabbit vegetations for at least 50% of the dosing interval.
• Simulations indicated that even high-dose aminoglycoside regimens often failed to achieve uniform supra-MBC levels within simulated 10-mm human vegetations.

Conclusions:

• Aminoglycoside distribution in aortic endocarditis is suboptimal, with poor penetration into vegetation centers.
• Higher-than-recommended daily doses of aminoglycosides may be necessary to achieve therapeutic intravegetation levels.
• These findings support further investigation into high-dose aminoglycoside regimens for experimental endocarditis treatment.