From the Guidelines
Flecainide does not have a specific reversible medicine or antidote, and management of its toxicity involves supportive care. The primary mechanism of flecainide's action is sodium channel blockade, and management involves sodium bicarbonate administration (typically 1-2 mEq/kg IV bolus, followed by infusion) to overcome this blockade 1. Hypertonic sodium solutions may also be used. For severe cases, intravenous fat emulsion (lipid rescue therapy) at 1.5 mL/kg bolus followed by 0.25 mL/kg/min infusion for 30-60 minutes may help bind the drug. Some key points to consider in managing flecainide toxicity include:
- Extracorporeal treatments like hemodialysis are generally ineffective due to flecainide's large volume of distribution 1.
- Cardiac monitoring is essential, and treatment of arrhythmias may require temporary pacing.
- Vasopressors or inotropes may be needed for hypotension.
- Prevention of flecainide toxicity is important through proper dosing, especially in patients with renal or hepatic impairment, and avoiding drug interactions that increase flecainide levels, particularly with CYP2D6 inhibitors 1. It is also important to note that flecainide and propafenone have a risk of proarrhythmia in patients with structural heart disease or ischemic heart disease and are contraindicated in these patient groups 1. In patients without structural heart disease or ischemic heart disease who have symptomatic recurrent atrial flutter, flecainide or propafenone may be considered to maintain sinus rhythm 1. However, the risk of 1:1 conduction may be reduced by coadministration of medications that slow AV nodal conduction, such as beta blockers, verapamil, or diltiazem 1.
From the Research
Reversible Medicine to Flecainide
There are no specific reversible medicines mentioned in the provided studies for flecainide toxicity. However, the following points can be considered:
- Flecainide toxicity can be treated with cardiopulmonary support, such as peripheral cardiopulmonary bypass support (CBS), to maintain perfusion of the liver and allow clearance of the drug 2.
- Treatment of flecainide toxicity is often focused on supportive care and managing symptoms, as there is no specific antidote available 3, 4.
- In some cases, treatment with beta-blockers may be used in conjunction with flecainide to prevent ventricular arrhythmias in patients with arrhythmogenic right ventricular cardiomyopathy 5.
Key Considerations
- Flecainide toxicity can cause serious side effects, including cardiac arrest, dysrhythmias, and heart failure 3.
- The diagnosis of flecainide toxicity can be difficult, as the flecainide serum level may take days to result 3.
- Electrocardiogram findings can suggest flecainide toxicity as the etiology 3, 4.
- Treatment of flecainide toxicity should be initiated promptly to prevent serious complications 3, 2, 4.
Treatment Approaches
- Cardiopulmonary support, such as CBS, may be used to treat severe flecainide overdose 2.
- Supportive care and management of symptoms are often the primary treatment approaches for flecainide toxicity 3, 4.
- Beta-blockers may be used in conjunction with flecainide to prevent ventricular arrhythmias in certain patient populations 5.