Population pharmacokinetic modeling and optimal sampling strategy for Bayesian estimation of amikacin exposure in critically ill septic patients.
Because the sepsis-induced pharmacokinetic (PK) modifications need to be considered in aminoglycoside dosing, the present study aimed to develop a population PK model for amikacin (AMK) in severe sepsis and to subsequently propose an optimal sampling strategy suitable for Bayesian estimation of the drug PK parameters. Concentration-time profiles for AMK were obtained from 88 critically ill septic patients during the first 24 hours of antibiotic treatment. The population PK model was developed using a nonlinear mixed effects modeling approach. Covariate analysis included demographic data, pathophysiological characteristics, and comedication. Optimal sampling times were selected based on a robust Bayesian design criterion. Taking into account clinical constraints, a two-point sampling approach was investigated. A two-compartment model with first-order elimination best fitted the AMK concentrations. Population PK estimates were 19.2 and 9.34 L for the central and peripheral volume of distribution and 4.31 and 2.21 L/h for the intercompartmental and total body clearance. Creatinine clearance estimated using the Cockcroft-Gault equation was retained in the final model. The two optimal sampling times were 1 hour and 6 hours after onset of the drug infusion. Predictive performance of individual Bayes estimates computed using the proposed optimal sampling strategy was reported: mean prediction errors were less than 5% and root mean square errors were less than 30%. The present study confirmed the significant influence of the creatinine clearance on the PK disposition of AMK during the first hours of treatment in critically ill septic patients. Based on the population estimates, an optimal sampling strategy suitable for Bayesian estimation of the drug PK parameters was developed, meeting the need of clinical practice.
Louvain Centre for Toxicology and Applied Pharmacology, Université catholique de Louvain, Brussels, Belgium.
Isabelle K
IK
Delattre
Flora T
FT
Musuamba
Joakim
J
Nyberg
Fabio S
FS
Taccone
Pierre-François
PF
Laterre
Roger K
RK
Verbeeck
Frédérique
F
Jacobs
Pierre E
PE
Wallemacq
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000583:Amikacin / Q000493:pharmacokinetics* / Q000627:therapeutic use; D000900:Anti-Bacterial Agents / Q000493:pharmacokinetics* / Q000627:therapeutic use; D001499:Bayes Theorem; D003404:Creatinine / Q000097:blood; D016638:Critical Illness; D016903:Drug Monitoring / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D008954:Models, Biological; D018805:Sepsis / Q000097:blood* / Q000188:drug therapy; D014018:Tissue Distribution
D000900:Anti-Bacterial Agents; D000583:Amikacin; D003404:Creatinine