Which drug class includes medications like metoprolol and atenolol?

The correct answer is the class of medications known as beta-blockers. Metoprolol and atenolol are both classified as beta-blockers, which primarily function by blocking the beta-adrenergic receptors in the heart. This action results in a reduced heart rate and decreased myocardial contractility, which ultimately helps in managing conditions such as hypertension, angina, and heart failure.

Beta-blockers also play a role in improving survival rates following a myocardial infarction. They can help to decrease the heart's workload and lower blood pressure, providing cardiovascular protection. This makes them particularly valuable in various cardiac scenarios.

In contrast, other drug classes mentioned do not include either metoprolol or atenolol. Calcium channel blockers work by preventing calcium from entering the cells of the heart and blood vessels, leading to relaxation and dilation. ACE inhibitors act to inhibit the angiotensin-converting enzyme, thus decreasing blood pressure and reducing strain on the heart. Diuretics help to eliminate excess fluid from the body and reduce blood pressure, but they do so through a completely different mechanism. Hence, the classification of metoprolol and atenolol as beta-blockers is accurate and reflects their pharmacological action and clinical application.