# Wide Spectrum of Flecainide Toxicity: A Case Report and Literature Review

## TL;DR

A 79-year-old woman on flecainide therapy developed toxicity symptoms like hallucinations and bradycardia, which resolved after stopping the drug.

## Contribution

This case report highlights rare manifestations of flecainide toxicity, including encephalopathy and visual hallucinations.

## Key findings

- Flecainide toxicity presented with altered mental status, visual hallucinations, and bradycardia.
- Acute kidney injury contributed to elevated flecainide levels in the patient.
- Discontinuation of flecainide led to rapid symptom resolution and ECG normalization.

## Abstract

Flecainide toxicity is a rare but serious condition that can present with a wide range of clinical symptoms. We report the case of a 79-year-old female with paroxysmal atrial fibrillation on flecainide therapy who developed altered mental status, visual hallucinations, and bradycardia. Laboratory results revealed an acute kidney injury, which contributed to elevated flecainide levels. Discontinuation of flecainide led to a rapid resolution of symptoms and normalization of ECG findings. This case underscores the critical need for careful monitoring of renal function and potential drug interactions in patients receiving flecainide to prevent toxicity, highlighting the wide range of flecainide toxicity, including rare manifestations such as encephalopathy and visual hallucinations.