What is the antiarrhythmic medication for Brugada syndrome?

From the Guidelines

Quinidine is the primary antiarrhythmic medication recommended for Brugada syndrome, particularly for patients with recurrent ventricular arrhythmias or those who have experienced electrical storms. The typical dosage ranges from 300-600 mg twice daily of quinidine sulfate, or 324-648 mg twice daily of quinidine gluconate, with dosing adjusted based on patient response and QT interval monitoring 1. Treatment is typically long-term for symptomatic patients. Quinidine works by blocking the transient outward potassium current (Ito), which helps normalize the ionic imbalance in the cardiac action potential that characterizes Brugada syndrome. This medication is particularly effective because it addresses the specific ion channel dysfunction in Brugada syndrome, helping to restore the epicardial action potential dome and prevent phase 2 reentry that can trigger ventricular arrhythmias.

Some key points to consider when using quinidine for Brugada syndrome include:

• Monitoring for side effects, such as gastrointestinal disturbances, QT prolongation, or thrombocytopenia 1
• Adjusting the dosage based on patient response and QT interval monitoring 1
• Considering alternative treatments, such as isoproterenol infusion (2-10 μg/min), for patients who cannot tolerate quinidine due to side effects 1
• Implantable cardioverter-defibrillator (ICD) remains the definitive therapy for preventing sudden cardiac death in high-risk patients 1

It's also important to note that the use of quinidine in Brugada syndrome is supported by guidelines from reputable organizations, such as the American College of Cardiology and the European Society of Cardiology 1. Overall, quinidine is a valuable treatment option for patients with Brugada syndrome, particularly those with recurrent ventricular arrhythmias or electrical storms.

From the Research

Antiarrhythmic Treatment for Brugada Syndrome

• Brugada syndrome is a genetic disorder that can lead to life-threatening arrhythmias, and various studies have investigated the efficacy of antiarrhythmic medications in preventing these arrhythmias 2, 3, 4, 5, 6.

Quinidine as a Treatment Option

• Quinidine, a Class Ia antiarrhythmic drug, has been shown to be effective in preventing ventricular fibrillation (VF) induction in patients with Brugada syndrome 2, 4, 5.
• Low-dose quinidine (≤200 mg/day) has been found to effectively reduce shocks in Brugada syndrome patients with an implantable cardioverter-defibrillator (ICD) 3.
• Quinidine has also been shown to prevent VF recurrence in patients with Brugada syndrome, with a significant reduction in arrhythmic events observed during follow-up periods 2, 4, 6.

Efficacy and Safety of Quinidine

• The efficacy of quinidine in preventing VF induction and recurrence has been demonstrated in several studies, with response rates ranging from 44% to 88% 2, 3, 4.
• Quinidine has been found to be generally well-tolerated, with side effects observed in a minority of patients, including diarrhea, leukopenia, and QT interval prolongation 2, 3, 4, 6.

Comparison with Other Treatments

• ICD therapy is currently considered the only effective treatment for high-risk patients with Brugada syndrome, but quinidine may be a useful adjunctive therapy for patients with frequent ICD discharges 2, 4.
• Hydroquinidine, a derivative of quinidine, has also been shown to be effective in preventing VT/VF inducibility in asymptomatic patients with Brugada syndrome and inducible arrhythmia 6.