Quinidine is an antiarrhythmic drug that may reduce the chance of serious abnormal heart rhythms occurring in some people with Brugada syndrome.[1][31] It is most frequently used in people with Brugada syndrome who have an ICD and have experienced several episodes of life-threatening arrhythmias, but may also be used in people at high risk of arrhythmias but in whom an ICD is not appropriate.[3]