AEMCA Practice Exam

Which medicine is an example of a non-selective beta blocker?

1. Atenolol

2. Metoprolol

3. Propranolol

4. Bisoprolol

The correct answer is: Propranolol

Propranolol is classified as a non-selective beta blocker because it effectively blocks both beta-1 and beta-2 adrenergic receptors. This characteristic enables it to influence a wider range of physiological effects compared to selective beta blockers, which target only specific receptor types. Non-selective beta blockers like propranolol are often used to treat various conditions, including hypertension, anxiety, and certain forms of tremors, due to their broader mechanism of action. The ability to block both types of receptors means that propranolol can affect heart rate and cardiac output (via beta-1 receptor blockade) while also affecting vascular smooth muscle and bronchial passages (via beta-2 receptor blockade). In contrast, atenolol, metoprolol, and bisoprolol are selective beta-1 blockers, primarily impacting the heart's functions, which typically results in fewer side effects related to respiratory issues and other systems influenced by beta-2 receptor activity. This selectivity makes these drugs preferable in certain populations, particularly those with respiratory conditions.