A 62-year-old man with a medical history of AF was admitted to our emergency department for altered mental status. The ECG at the time of admission showed a Brugada pattern, triggered by a flecainide overdose (about 1 g), in association with an unknown dose of lamotrigine and quetiapine. After discontinuation of all medications, the Brugada pattern disappeared and his ECG showed no abnormalities. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: In patients with AF, the use of class IC antidysrhythmic drugs, if overdosed, can trigger a Brugada ECG pattern, and therefore it can increase the risk for malignant dysrhythmias. It is important to provide, to all patients with a Brugada ECG pattern, a list of drugs to avoid, and to underline the synergistic interplay between drugs, taking into consideration all patients' comorbidities.