Richard Jonathan Levy

All Publications

• Multicenter Population Pharmacokinetics of Fentanyl in Neonatal Surgical Patients Using Dried Blood Spot Specimen Collection Demonstrates Maturation of Elimination Clearance. Anesthesia and analgesia Rzasa Lynn, R. S., Henthorn, T. K., Zuk, J., Hammer, G. B., Drover, D. R., Levy, R. J., Maxwell, L. G., Sadhasivam, S., Suresh, S., Galinkin, J. L. 2024; 138 (2): 447-455

  Abstract

  Fentanyl is widely used for analgesia and sedation in neonates, but pharmacokinetic (PK) analysis in this population has been limited by the relatively large sample volumes required for plasma-based assays.In this multicenter observational study of fentanyl kinetics in neonates up to 42 weeks of postmenstrual age (PMA) who received fentanyl boluses and continuous infusions, dried blood spots were used for small-volume sampling. A population PK analysis was used to describe fentanyl disposition in term and preterm neonates. Covariates for the model parameters, including body weight, PMA, birth status (preterm or term), and presence of congenital cardiac disease, were assessed in a stepwise manner.Clearance was estimated to be greater than adult clearance of fentanyl and varied with weight. Covariate selection did not yield a significant relationship for age as a continuous or dichotomous variable (term or preterm, the latter defined as birth with PMA of <37 weeks) and clearance.A supra-allometric effect on clearance was determined during covariate analyses (exponential scaling factor for body weight >0.75), as has been described in population PK models that account for maturation of intrinsic clearance (here, predominantly hepatic microsomal activity) in addition to scaling for weight, both of which impact clearance in this age group.

  View details for DOI 10.1213/ANE.0000000000006808

  View details for PubMedID 38215717

• Anesthetic and Sedative Neurotoxicity in the Patient with Congenital Heart Disease ANESTHESIA FOR CONGENITAL HEART DISEASE, 3RD EDITION Levy, R. J., Wise-Faberowski, L., Andropoulos, D. B. edited by Andropoulos, D. B., Stayer, S., Mossad, E. B., MillerHance, W. C. 2015: 184–98

  View details for Web of Science ID 000385225800010