What is a major side effect of beta-adrenergic blockers like propranolol?

What is a major side effect of beta-adrenergic blockers like propranolol?

• A. Increased heart rate and contractility
• B. Bronchospasm and hypoglycemia
• C. Elevated blood pressure
• D. Decreased respiratory rate

Answer: (B)

Beta-adrenergic blockers, such as propranolol, primarily work by blocking beta-adrenergic receptors, which are found in various tissues throughout the body, including the heart, lungs, and pancreas. A significant side effect of these medications is bronchospasm and hypoglycemia, particularly in individuals with asthma or diabetes. Bronchospasm occurs due to the blockade of beta-2 adrenergic receptors in the bronchial smooth muscle, leading to constriction of the airways and difficulty breathing. This is particularly concerning for patients with underlying respiratory conditions. Hypoglycemia can occur because beta-blockers inhibit glycogenolysis and gluconeogenesis in the liver, which are processes that increase blood glucose levels, making patients more susceptible to low blood sugar, especially in those taking insulin or other antidiabetic medications. The other choices presented do not align with the typical side effects of beta-adrenergic blockers. For example, increased heart rate and contractility is contrary to the expected effects of these medications, which are designed to decrease heart rate and myocardial contractility. Elevated blood pressure is also not a side effect; beta-blockers are typically used to lower blood pressure. Lastly, a decrease in respiratory rate is not a direct

Beta-adrenergic blockers, such as propranolol, primarily work by blocking beta-adrenergic receptors, which are found in various tissues throughout the body, including the heart, lungs, and pancreas. A significant side effect of these medications is bronchospasm and hypoglycemia, particularly in individuals with asthma or diabetes.

Bronchospasm occurs due to the blockade of beta-2 adrenergic receptors in the bronchial smooth muscle, leading to constriction of the airways and difficulty breathing. This is particularly concerning for patients with underlying respiratory conditions. Hypoglycemia can occur because beta-blockers inhibit glycogenolysis and gluconeogenesis in the liver, which are processes that increase blood glucose levels, making patients more susceptible to low blood sugar, especially in those taking insulin or other antidiabetic medications.

The other choices presented do not align with the typical side effects of beta-adrenergic blockers. For example, increased heart rate and contractility is contrary to the expected effects of these medications, which are designed to decrease heart rate and myocardial contractility. Elevated blood pressure is also not a side effect; beta-blockers are typically used to lower blood pressure. Lastly, a decrease in respiratory rate is not a direct