NAPLEX Practice Exam 2025 – Comprehensive Test Preparation

In structural heart disease such as heart failure (HF) or myocardial infarction (MI), medications that can further worsen the condition should be avoided. In this case, both Flecainide and Propafenone are Class I antiarrhythmic drugs that have negative inotropic effects and can exacerbate heart failure and increase the risk of arrhythmias in patients with structural heart disease. Therefore, it is contraindicated to use Flecainide and Propafenone in patients with structural heart disease.

The other options:

B. Quinidine and Disopyramide: These are also Class I antiarrhythmic drugs and can have similar effects as Flecainide and Propafenone in patients with structural heart disease.

C. Mexiletine and Lidocaine: These are Class Ib antiarrhythmic drugs that have less negative inotropic effects compared to Class Ia drugs like Flecainide and Propafenone. They may be considered in certain situations in patients with structural heart disease.

D. Sotalol and Dronedarone: While Sotalol is a Class III antiarrhythmic drug that can prolong the QT interval and should be used with caution in patients with structural heart disease, Dronedarone is a Class III antiarrhythmic drug that is generally considered safer in patients with structural heart disease compared to Flecainide and Propafenone, but still should be used with caution.