Case report: Use of therapeutic drug monitoring and pharmacogenetic testing as opportunities to individualize care in a case of flecainide toxicity after fetal supraventricular tachycardia.

Creator(s)

Ronald Palmen, Children's Mercy Kansas CityFollow
Tracy L. Sandritter, Children's Mercy HospitalFollow
Lindsey Malloy-Walton, Children's Mercy HospitalFollow
Christopher Follansbee, Children's Mercy Kansas City
Jonathan B. Wagner, Children's Mercy HospitalFollow

Document Type

Article

Publication Date

6-28-2023

Identifier

DOI: 10.3389/fped.2023.1168619; PMCID: PMC10337585

Abstract

Flecainide is a class IC antiarrhythmic utilized in prophylaxis of refractory paroxysmal supraventricular tachycardias in pediatric populations. Despite being a highly effective agent, its narrow therapeutic index increases the risk of toxicity and proarrhythmic events, including wide-complex tachycardia. In the absence of direct plasma sampling in the fetus to quantitate flecainide systemic concentrations, clinicians typically make drug dosing decisions from maternal plasma concentrations and QRS duration on maternal ECGs. There remains a paucity of standard guidelines and data to inform the timing and frequency of the aforementioned test in pregnancy and timing of flecainide discontinuation prior to childbirth. Flecainide primarily undergoes metabolism via cytochrome P450 (CYP). Given the variance of CYP-mediated metabolism at the level of the individual patient, pharmacogenomics can be considered in patients who present with flecainide toxicity to determine the maternal vs. fetal factors as an etiology for the event. Finally, pharmacogenetic testing can be utilized as an adjunct to guide flecainide dosing decisions, but must be done with caution in neonatestachycardia, who experienced flecainide toxicity immediately post-partum and was trialed unsuccessfully on multiple alternative antiarrhythmics without rhythm control.

Journal Title

Front Pediatr

Volume

11

First Page

1168619

Last Page

1168619

Keywords

drug monitoring; flecainide; pharmacogenetic; pharmacogenomics; toxicity

Comments

This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

Publisher's Link: https://www.frontiersin.org/articles/10.3389/fped.2023.1168619/full

Recommended Citation

Palmen R, Sandritter T, Malloy-Walton L, Follansbee C, Wagner JB. Case report: Use of therapeutic drug monitoring and pharmacogenetic testing as opportunities to individualize care in a case of flecainide toxicity after fetal supraventricular tachycardia. Front Pediatr. 2023;11:1168619. Published 2023 Jun 28. doi:10.3389/fped.2023.1168619