NAPLEX (North American Pharmacist Licensure Examination) Practice Exam

What should be done to the digoxin dose when adding amiodarone?

1. Increase digoxin dose by 50%

2. No change to digoxin dose

3. Decrease digoxin dose by 25%

4. Decrease digoxin dose by 50%

The correct answer is: Decrease digoxin dose by 50%

When adding amiodarone to a patient's medication regimen, it is important to be aware of potential drug interactions. Amiodarone can increase the serum concentration of digoxin, leading to an increased risk of digoxin toxicity. Therefore, it is recommended to decrease the digoxin dose when adding amiodarone to avoid toxicity. In this case, decreasing the digoxin dose by 50% (option D) is the correct choice to help prevent adverse effects related to increased digoxin levels in the presence of amiodarone.