From the Guidelines
Flecainide can cause hypotension, although it is not a commonly reported side effect, and its occurrence is more likely with intravenous administration or higher doses. Flecainide is a Class IC antiarrhythmic medication primarily used to treat supraventricular arrhythmias and ventricular tachycardia. According to the 2015 ACC/AHA/HRS guideline for the management of adult patients with supraventricular tachycardia 1, the potential adverse effects of flecainide include atrial flutter with 1:1 AV conduction, QT prolongation, torsades de pointes, worsening HF, and bradycardia, but hypotension is not explicitly listed as a common side effect. However, another study 1 mentions that flecainide can cause hypotension, particularly when administered intravenously or at higher doses. The mechanism behind flecainide-induced hypotension relates to its sodium channel blocking properties, which can decrease cardiac contractility and potentially reduce cardiac output, leading to lower blood pressure.
- Patients with pre-existing heart failure, structural heart disease, or those taking other medications that lower blood pressure may be at higher risk for this side effect.
- If a patient experiences significant hypotension while taking flecainide, they should contact their healthcare provider immediately, as dosage adjustment or medication change may be necessary.
- Regular blood pressure monitoring is advisable when initiating flecainide therapy or adjusting the dose, especially in patients with cardiovascular disease or those taking other antihypertensive medications.
From the FDA Drug Label
In less than 1% of patients: Body as a Whole: swollen lips, tongue and mouth; arthralgia, bronchospasm, myalgia; Cardiovascular: angina pectoris, second-degree and third-degree AV block, bradycardia, hypertension, hypotension; The answer is: Yes, flecainide can cause hypotension in less than 1% of patients [@1@].
From the Research
Flecainide and Hypotension
- Flecainide is an antiarrhythmic medication used to treat various heart rhythm disorders, including atrial fibrillation.
- According to a study published in 2006 2, hypotension (systolic blood pressure < 90 mmHg) was reported in 1 patient out of 23 consecutive patients who received intravenous flecainide for paroxysmal atrial fibrillation.
- Another study published in 2022 3 reported a case of a 62-year-old man on dialysis who presented with bradycardia and hypotension after discontinuing flecainide and metoprolol, suggesting that flecainide toxicity can manifest with hypotension.
- A case report published in 2019 4 described a 52-year-old woman with paroxysmal atrial fibrillation who developed cardiogenic shock, including hypotension, after receiving a therapeutic dose of flecainide.
- However, a study published in 2025 5 did not report any cases of hypotension in patients with structural heart disease who received flecainide.
Mechanism of Flecainide-Induced Hypotension
- Flecainide can slow atrial, AV nodal, His-Purkinje, and intraventricular conduction, which may lead to decreased cardiac output and hypotension 6.
- The drug can also cause a small but significant increase in the QT interval duration, which may contribute to the development of hypotension 6.
- In addition, flecainide can induce severe cardiogenic shock in overdose or in patients with increased susceptibility to its negative inotropic effect 4.