Which of the following drugs is NOT used for rate control in atrial fibrillation?

Rate control in atrial fibrillation focuses on slowing down the heart rate to improve symptoms and patient comfort. Beta-blockers, calcium channel blockers, and digoxin are all pharmacologic options that directly influence the electrical conduction system of the heart, thereby reducing heart rate.

Beta-blockers work by blocking the effects of adrenaline on the beta-adrenergic receptors, resulting in a decreased heart rate. Calcium channel blockers, particularly the non-dihydropyridine types like verapamil and diltiazem, slow down conduction through the AV node and help control the heart rate. Digoxin increases vagal tone and decreases conduction through the AV node as well, leading to a reduction in heart rate.

In contrast, anticoagulants do not have any effect on the heart rate. They are used to prevent thromboembolism in patients with atrial fibrillation but do not influence how fast the heart beats. This makes anticoagulants the correct answer as they are not involved in rate control. Thus, recognizing the therapeutic roles of medications in managing atrial fibrillation is crucial for achieving optimal patient outcomes.