Oritavancin Multiple Dosing for Complex Infections: A Pharmacokinetic/Pharmacodynamic Simulation Study.
Ana Alarcia-Lacalle1, Miguel Ángel Morán-Rodríguez2,3, Laura Morata4
1Pharmacokinetic, Nanotechnology and Gene Therapy Group (PharmaNanoGene), Faculty of Pharmacy, Lascaray Research Centre, University of the Basque Country EHU, Paseo de la Universidad n° 7, 01006 Vitoria-Gasteiz, Spain.
Pharmaceutics
|May 27, 2026
Summary
Establishing optimal oritavancin dosing for complex infections is crucial. This study used PK/PD modeling to identify effective multiple-dosing regimens, suggesting specific strategies for various bacterial minimum inhibitory concentrations (MICs).
Area of Science:
- Pharmacokinetics and Pharmacodynamics (PK/PD)
- Infectious Diseases
- Antimicrobial Therapy
Background:
- Oritavancin is used for complex infections, but optimal dosing regimens are not well-established.
- Lack of defined dosing strategies presents challenges in achieving effective oritavancin concentrations.
- This study addresses the need for evidence-based dosing to improve treatment outcomes.
Purpose of the Study:
- To identify effective multiple-dosing regimens for oritavancin in long-term infections.
- To utilize PK/PD modeling and Monte Carlo simulations to evaluate various dosing strategies.
- To assess the probability of target attainment (PTA) for different oritavancin regimens against varying minimum inhibitory concentrations (MICs).
Main Methods:
- Simulated plasma concentration-time profiles for multiple oritavancin dosing regimens.
- Evaluated regimens included single and multiple doses with varying intervals (e.g., q7d, q10d, q14d, q21d).
- Calculated PTA using PK/PD targets: AUC0-24/MIC, Cmax/MIC, and fCmin > MIC.
Main Results:
- All regimens achieved 100% PTA up to MIC of 0.5 mg/L using AUC0-24/MIC and Cmax/MIC targets.
- Using AUC0-72/MIC, regimens were adequate for MICs up to 0.125 mg/L.
- For fCmin > MIC, several regimens (e.g., 1200 mg day 1 + 800 mg q7d, 1200 mg q10d) showed potential for MICs of 0.25 mg/L.
Conclusions:
- Further clinical studies are required to correlate plasma concentrations, MICs, and clinical outcomes in complex infections.
- The PK/PD target fCmin > MIC warrants investigation for oritavancin therapy in complex infections.
- Specific multiple-dosing regimens show promise for treating infections caused by bacteria with defined MIC values.
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