Which of the following medications is classified as a beta-blocking agent?

Atenolol is classified as a beta-blocking agent, which is a type of medication that works by blocking the effects of adrenaline on the beta-adrenergic receptors in the body. This blocking action leads to a decrease in heart rate and blood pressure, making beta-blockers effective in treating conditions such as hypertension, heart failure, and certain types of arrhythmias.

Beta-blockers like atenolol also have additional benefits, including reducing the risk of repeated heart attacks and managing anxiety symptoms due to their calming effects on the cardiovascular system. This is why atenolol is often prescribed for cardiac-related conditions and is recognized as a key medication in cardiovascular pharmacotherapy.

In contrast, lisinopril is an ACE inhibitor, primarily used for blood pressure management and heart failure, while metformin is an oral antidiabetic agent that helps control blood sugar levels in patients with type 2 diabetes. Gabapentin is an anticonvulsant medication, commonly used to treat neuropathic pain and seizures, and does not fall under the category of beta-blockers. These distinctions highlight why atenolol stands out as the only beta-blocking agent among the listed medications.