Pharmacokinetic modeling of tranexamic acid for patients undergoing cardiac surgery with normal renal function and model simulations for patients with renal impairment

Qi Joy Yang, Angela Jerath, Robert R. Bies, Marcin Wąsowicz, K. Sandy Pang

Research output: Contribution to journalArticle

14 Scopus citations

Abstract

Tranexamic acid (TXA), an effective anti-fibrinolytic agent that is cleared by glomerular filtration, is used widely for cardiopulmonary bypass (CPB) surgery. However, an effective dosing regimen has not been fully developed in patients with renal impairment. The aims of this study were to characterize the inter-patient variability associated with pharmacokinetic parameters and to recommend a new dosing adjustment based on the BART dosing regimen for CPB patients with chronic renal dysfunction (CRD). Recently published data on CPB patients with normal renal function (n = 15) were re-examined with a two-compartment model using the ADAPT5® and NONMEMVII® to identify covariates that explain inter-patient variability and to ascertain whether sampling strategies might affect parameter estimation. A series of simulations was performed to adjust the BART dosing regimen for CPB patients with renal impairment. Based on the two-compartmental model, the number of samples obtained after discontinuation of TXA infusion was found not to be critical in parameter estimation (p > 0.05). Both body weight and creatinine clearance were identified as significant covariates (p < 0.005). Simulations showed significantly higher than normal TXA concentrations in CRD patients who received the standard dosing regimen in the BART trial. Adjustment of the maintenance infusion rate based on the percent reduction in renal clearance resulted in predicted plasma TXA concentrations that were safe and therapeutic (~100 mg·L<sup>-1</sup>). Our proposed dosing regimen, with consideration of renal function, is predicted to maintain effective target plasma concentrations below those associated with toxicity for patients with renal failure for CPB.

Original languageEnglish (US)
Pages (from-to)294-307
Number of pages14
JournalBiopharmaceutics and Drug Disposition
Volume36
Issue number5
DOIs
StatePublished - Jul 1 2015

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Keywords

  • BART dose
  • cardiopulmonary bypass
  • creatinine clearance
  • dose optimization
  • glomerular filtration
  • pharmacokinetic or population modeling
  • renal clearance
  • renal dysfunction
  • tranexamic acid

ASJC Scopus subject areas

  • Pharmacology (medical)
  • Pharmaceutical Science
  • Pharmacology

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