What medications can trigger Brugada syndrome?

Medications That Trigger Brugada Syndrome

Multiple medication classes can trigger or unmask Brugada syndrome, with sodium channel blockers being the most significant risk, and patients should avoid these medications along with certain psychotropic drugs, anesthetics, and other agents listed on www.brugadadrugs.org. 1, 2

Sodium Channel Blockers

These medications pose the highest risk and are most commonly associated with unmasking the Brugada ECG pattern:

• Class I antiarrhythmics:
  • Flecainide
  • Procainamide
  • Ajmaline (most potent at unmasking Brugada pattern) 3
  • Pilsicainide
  • Propafenone
  • Disopyramide

Psychotropic Medications

• Tricyclic antidepressants 2, 4
• Selective serotonin reuptake inhibitors (e.g., fluoxetine) 4
• Other psychiatric medications:
  • Lithium
  • Trifluoperazine

Calcium Channel Blockers

Certain calcium channel blockers should be avoided in Brugada syndrome patients 2

Beta-Blockers

All beta-blockers are potentially harmful in Brugada syndrome, unlike in other channelopathies where they may be beneficial 2

Other Medications and Substances

• Anesthetic agents 1
• Antihistamines 4
• Cocaine 1, 4
• Alcohol (excessive intake) 1, 2

Mechanism of Action

Most triggering medications work through one of these mechanisms:

1. Sodium channel blockade - directly affects the already dysfunctional sodium channels in Brugada syndrome
2. Alteration of autonomic tone - changes that promote the Brugada ECG pattern
3. Other ion channel effects - affecting potassium or calcium currents that can worsen the underlying electrophysiological abnormality

Clinical Implications

Diagnostic Challenges

Sodium channel blockers (ajmaline, flecainide, procainamide) are deliberately used as provocative agents during diagnostic evaluation to reveal concealed Brugada patterns 1, 5. However, these challenges must be performed under careful monitoring, and the test should be terminated immediately if:

• Ventricular arrhythmias develop
• Marked QRS widening occurs
• Type 1 Brugada ECG pattern emerges 1

Patient Safety Recommendations

1. Patients should check medication safety on www.brugadadrugs.org before taking any new drugs 1, 2
2. Prompt treatment of fever with antipyretic drugs is essential as fever can unmask Brugada ECG pattern and trigger arrhythmias 1, 2
3. Avoid excessive alcohol intake and large meals 1, 2
4. Isoproterenol can be used to treat electrical storms in Brugada syndrome 1, 2
5. Quinidine may be considered for patients with recurrent ICD shocks or for treatment of supraventricular arrhythmias 1, 2

Pitfalls and Caveats

• A drug-induced Brugada pattern doesn't always indicate true Brugada syndrome - further evaluation is needed 5
• Incidental findings of Brugada pattern during medication administration (e.g., procainamide for atrial fibrillation) require cardiology referral 5
• The relative potency of sodium channel blockers varies - ajmaline is more effective at unmasking Brugada pattern than flecainide (32% of patients may show negative response to flecainide but positive to ajmaline) 3
• Patients with drug-induced Brugada pattern should be referred to cardiology for risk stratification even if the pattern resolves after medication discontinuation 5