PK/PD modeling of daptomycin against MRSA and MRSE and Monte Carlo simulation for bacteremia treatment

Bruna Menezes; Izabel Alves; Keli Staudt; Betina Beltrame; Lessandra Michelin; Bibiana Verlindo de Araújo; Leandro Tasso

doi:10.1007/s42770-021-00582-4

PK/PD modeling of daptomycin against MRSA and MRSE and Monte Carlo simulation for bacteremia treatment

Braz J Microbiol. 2021 Dec;52(4):1967-1979. doi: 10.1007/s42770-021-00582-4. Epub 2021 Aug 2.

Authors

Bruna Menezes¹, Izabel Alves², Keli Staudt², Betina Beltrame³, Lessandra Michelin⁴, Bibiana Verlindo de Araújo², Leandro Tasso^{5

6}

Affiliations

¹ Programa de Pós-Graduação Em Biotecnologia, Universidade de Caxias Do Sul, Caxias do Sul, Brazil.
² Programa de Pós-Graduação Em Ciências Farmacêuticas, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, Brazil.
³ Curso de Farmácia, Universidade de Caxias Do Sul, Caxias do Sul, Brazil.
⁴ Programa de Pós-Graduação Em Ciências da Saúde, Universidade de Caxias Do Sul, Rua Francisco Getúlio Vargas, Caxias do Sul, 1130, 95070-560, Brazil.
⁵ Programa de Pós-Graduação Em Biotecnologia, Universidade de Caxias Do Sul, Caxias do Sul, Brazil. ltasso@ucs.br.
⁶ Programa de Pós-Graduação Em Ciências da Saúde, Universidade de Caxias Do Sul, Rua Francisco Getúlio Vargas, Caxias do Sul, 1130, 95070-560, Brazil. ltasso@ucs.br.

Abstract

Objectives: The aim of this study was to investigate the effect of daptomycin against methicillin-resistant staphylococci (MRSA and MRSE) bacteremia using computer modeling.

Methods: A pharmacokinetic/pharmacodynamic (PK/PD) modeling strategy to explain the data from an in vitro dynamic model employing time-kill curves for MRSA and MRSE was proposed. Bacterial killing was followed over time by determining viable counts and the resulting time-kill data was analyzed. Monte Carlo simulations were performed using pharmacokinetic parameters and pharmacodynamic data to determine the probabilities of target attainment and cumulative fractions of response in terms of area under the concentration curve/minimum inhibition concentration (MIC) targets of daptomycin. Simulations were conducted to assess the reduction in the number of colony-forming units (CFU)/mL for 18 days of treatment with daptomycin at doses of 6, 8, and 10 mg/kg/24 h or 48 h with variations in creatinine clearance (CL_CR): 15-29 mL/min/1.73 m², 30-49 mL/min/1.73 m², 50-100 mL/min/1.73 m², as well as for defining the probability of reaching the target fAUC/MIC = 80 in the same dose and clearance range. A PK/PD model with saturation in the number of bacteria in vitro, growth delay, and bacterial death, as well as Hill's factor, was used to describe the data for both MRSA and MRSE.

Results: Monte Carlo simulations showed that for MRSA there was a reduction > 2 log CFU/mL with doses ≥ 6 mg/kg/day in 75th percentile of the simulated population after 18 days of treatment with daptomycin, whereas for MRSE this reduction was observed in 95th percentile of the population.

Conclusions: The presented in vitro PK/PD model and associated modeling approach were able to characterize the time-kill kinetics of MRSA and MRSE. Our study based on PTAs suggests that doses ≥ 6 mg/kg/day of daptomycin should be used to treat bacteremia caused by MRSA and MRSE in patients with CL_CR of 15-29 mL/min/1.73 m². For patients with CL_CR ≥ 50 mL/min/1.73 m², it would be necessary to employ a dose of 10 mg/kg/day to treat complicated bacteremias.

Keywords: Bacteremia; Daptomycin; Monte Carlo simulation; PK/PD modeling.

MeSH terms

Anti-Bacterial Agents / pharmacokinetics
Anti-Bacterial Agents / pharmacology
Anti-Bacterial Agents / therapeutic use
Bacteremia* / drug therapy
Daptomycin* / pharmacokinetics
Daptomycin* / pharmacology
Daptomycin* / therapeutic use
Humans
Methicillin-Resistant Staphylococcus aureus* / drug effects
Microbial Sensitivity Tests
Monte Carlo Method*
Staphylococcal Infections* / drug therapy

Substances

Anti-Bacterial Agents
Daptomycin