1
|
Hall J, Edmundowicz D, Cronin E. Advanced Interatrial block induced by flecainide. J Electrocardiol 2024; 86:153767. [PMID: 39197226 DOI: 10.1016/j.jelectrocard.2024.153767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2024] [Accepted: 07/31/2024] [Indexed: 09/01/2024]
Abstract
We present a case of advanced interatrial block induced by flecainide toxicity. We discuss the implications of this conduction abnormality.
Collapse
Affiliation(s)
- Jillian Hall
- Section of Cardiology, Department of Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States of America.
| | - Daniel Edmundowicz
- Section of Cardiology, Department of Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States of America
| | - Edmond Cronin
- Section of Cardiology, Department of Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States of America
| |
Collapse
|
2
|
Seltzer J, Schneir A. Case Files from the University of California San Diego Medical Toxicology Fellowship: Neonatal Flecainide Toxicity from an Accidental Dosing Error. J Med Toxicol 2024; 20:314-323. [PMID: 38992232 PMCID: PMC11288226 DOI: 10.1007/s13181-024-01018-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2024] [Revised: 06/08/2024] [Accepted: 06/12/2024] [Indexed: 07/13/2024] Open
Affiliation(s)
- Justin Seltzer
- Division of Medical Toxicology, Department of Emergency Medicine, UC San Diego, 200 W. Arbor Dr #8676, 92103, San Diego, CA, United States.
| | - Aaron Schneir
- Division of Medical Toxicology, Department of Emergency Medicine, UC San Diego, 200 W. Arbor Dr #8676, 92103, San Diego, CA, United States
| |
Collapse
|
3
|
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. [PMID: 37449265 PMCID: PMC10337585 DOI: 10.3389/fped.2023.1168619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 06/12/2023] [Indexed: 07/18/2023] Open
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 neonates <2 weeks of age. This case report highlights utilization of pharmacogenomic testing and therapeutic drug monitoring as adjuncts to guide therapy for a newborn with refractory supraventricular tachycardia, who experienced flecainide toxicity immediately post-partum and was trialed unsuccessfully on multiple alternative antiarrhythmics without rhythm control.
Collapse
Affiliation(s)
- Ronald Palmen
- Children’s Mercy, Kansas City, MO, United States
- Department of Pediatrics, University of Missouri-Kansas City School of Medicine, Kansas City, MO, United States
- University of Missouri-Kansas City School of Medicine, Kansas City, MO, United States
| | - Tracy Sandritter
- Children’s Mercy, Kansas City, MO, United States
- University of Missouri-Kansas City School of Pharmacy, Kansas City, MO, United States
| | - Lindsey Malloy-Walton
- Children’s Mercy, Kansas City, MO, United States
- Department of Pediatrics, University of Missouri-Kansas City School of Medicine, Kansas City, MO, United States
- Ward Family Heart Center, Kansas City, MO, United States
| | - Christopher Follansbee
- Children’s Mercy, Kansas City, MO, United States
- Department of Pediatrics, University of Missouri-Kansas City School of Medicine, Kansas City, MO, United States
- Ward Family Heart Center, Kansas City, MO, United States
| | - Jonathan B. Wagner
- Children’s Mercy, Kansas City, MO, United States
- Department of Pediatrics, University of Missouri-Kansas City School of Medicine, Kansas City, MO, United States
- University of Missouri-Kansas City School of Medicine, Kansas City, MO, United States
- Ward Family Heart Center, Kansas City, MO, United States
- Division of Clinical Pharmacology, Toxicology and Therapeutic Innovation, Kansas City, MO, United States
| |
Collapse
|
4
|
Bhatt H, Regan W, Rosenthal E, Bellsham-Revell H. Flecainide toxicity: ECG changes associated with supratherapeutic levels in milk-fed infants. BMJ Case Rep 2023; 16:e252823. [PMID: 36731946 PMCID: PMC9896187 DOI: 10.1136/bcr-2022-252823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Flecainide is a class 1C antiarrhythmic and is highly effective for treating a wide range of arrhythmias. It is not licensed for children under the age of 12 years, but has been used safely for years in young children, particularly when first-line agents are not effective. Although toxicity does occur in both adult and paediatric populations, there have been very few reported instances of flecainide toxicity in neonates and children. Supratherapeutic levels of flecainide manifests on ECG with prolongation of the PR interval, QRS duration and QT, and can lead to life-threatening arrhythmias. In milk-fed infants receiving flecainide, regular feeding patterns are paramount to achieve a steady therapeutic state, as milk and dairy products are known to reduce the absorption of flecainide. This case series details four milk-fed infants admitted with ECG changes secondary to flecainide toxicity.
Collapse
Affiliation(s)
- Hitarth Bhatt
- Paediatric Cardiology, Evelina London Children's Hospital, London, UK
| | - Will Regan
- Paediatric Cardiology, Evelina London Children's Hospital, London, UK
| | - Eric Rosenthal
- Paediatric Cardiology, Evelina London Children's Hospital, London, UK
| | | |
Collapse
|