In a 68-year-old patient presenting with atrial fibrillation/flutter, which medication is commonly used for treatment?

Diltiazem is commonly used in the management of atrial fibrillation and flutter due to its effective capabilities as a calcium channel blocker, which helps to slow down the conduction through the atrioventricular (AV) node. This action can help control the ventricular rate in patients experiencing atrial fibrillation or flutter. Diltiazem is particularly beneficial for patients who may exhibit tachycardia, and it can also relieve symptoms related to rapid heart rates.

Other medications listed, while they may be used in specific cases or have certain roles, do not have the same level of effectiveness or first-line status specifically for controlling the heart rate in atrial fibrillation/flutter. Amiodarone is primarily an antiarrhythmic used for rhythm control rather than rate control, Digoxin may be utilized occasionally but is less favored due to its variable effects and risk for toxicity, and Atenolol, a beta-blocker, is also used but often less frequently than diltiazem for acute rate control in this context.