Which of the following is a common side effect of beta-agonist medications?

Beta-agonist medications are commonly used in the treatment of conditions such as asthma and chronic obstructive pulmonary disease (COPD). One of the recognized side effects of these medications is palpitations, which refers to the sensation of having a fast-beating, fluttering, or pounding heart. This occurs because beta-agonists stimulate beta-adrenergic receptors not only in the lungs where they relax bronchial smooth muscle but also in the heart, leading to increased heart rate and contractibility.

In contrast, weight gain, drowsiness, and skin rash are not typical side effects associated with beta-agonists. Weight gain is more often linked to other medication classes or long-term health changes rather than the short-term effects of beta-agonist use. Drowsiness is typically not expected as these medications can be stimulating in nature, and skin rashes would be more indicative of an allergic reaction or interaction with another medication rather than a common side effect of beta-agonists. Thus, the presence of palpitations aligns with the pharmacological action of beta-agonists and reflects a known side effect that practitioners and patients should monitor.