Key takeaways
Sotalol (Betapace) and quinidine are both antiarrhythmic medications used to treat heart rhythm problems, such as atrial fibrillation or flutter. However, they belong to different classes and have distinct mechanisms of action. Sotalol is a non-selective beta blocker and potassium channel blocker, while quinidine works by blocking sodium channels. Both medications are available as a lower-cost generic. Sotalol is typically taken twice a day, while quinidine is taken every 6 to 8 hours, depending on the formulation. Common side effects of sotalol include tiredness and dizziness, while quinidine often causes diarrhea and upset stomach. Both medications require careful monitoring due to potential serious side effects, but quinidine is less commonly used today because there are better alternatives. Sotalol can interact with antacids and certain blood pressure medications, while quinidine has many drug interactions that can affect its levels in the body.
