Theophylline Population Pharmacokinetics and Dosing in Children Following Congenital Heart Surgery With Cardiopulmonary Bypass. Journal of clinical pharmacology Frymoyer, A., Su, F., Grimm, P. C., Sutherland, S. M., Axelrod, D. M. 2016; 56 (9): 1084-1093

Abstract

Children undergoing cardiac surgery requiring cardiopulmonary bypass (CPB) frequently develop acute kidney injury due to renal ischemia. Theophylline, which improves renal perfusion via adenosine receptor inhibition, is a potential targeted therapy. However, children undergoing cardiac surgery and CPB commonly have alterations in drug pharmacokinetics. To help understand optimal aminophylline (salt formulation of theophylline) dosing strategies in this population, a population-based pharmacokinetic model was developed using nonlinear mixed-effects modeling (NONMEM) from 71 children (median age: 5 months [90% range: 1 week - 10 years]) who underwent cardiac surgery requiring CPB and received aminophylline as part of a previous randomized controlled trial. A one-compartment model with linear elimination adequately described the pharmacokinetics of theophylline. Weight scaled via allometry was a significant predictor of clearance and volume. In addition, allometric scaled clearance increased with age implemented as a power maturation function. Compared to prior reports in non-cardiac children, theophylline clearance was markedly reduced across age. Applying the final population pharmacokinetic model, optimized empiric dosing regimens were developed via Monte Carlo simulations. Doses 50-75% lower than those recommended in non-cardiac children were needed to achieve target serum concentrations of 5-10 mg/L. This article is protected by copyright. All rights reserved.

View details for DOI 10.1002/jcph.697

View details for PubMedID 26712558