A nurse is assisting in the care of a client who is taking metoprolol. The nurse should monitor the client for which of the following adverse effects?

Metoprolol is a beta-adrenergic blocker commonly used to manage hypertension, angina, heart failure, and certain arrhythmias. It works by selectively blocking beta-1 receptors in the heart, leading to decreased heart rate, reduced myocardial contractility, and lowered cardiac output. While these effects are therapeutic, they can also produce predictable adverse effects that require close nursing monitoring. Understanding these effects helps prevent complications such as excessive cardiac suppression. Rationale: A. Hypertension is not an expected adverse effect of metoprolol; instead, the medication is prescribed to lower blood pressure. By blocking beta-1 receptors, it reduces cardiac output and inhibits renin release from the kidneys, both of which contribute to decreased blood pressure. An increase in blood pressure would indicate treatment failure or another underlying issue rather than a drug side effect. B. Bradycardia is a common adverse effect of metoprolol due to its action on beta-1 receptors in the heart. By decreasing sympathetic stimulation, it slows the sinoatrial node firing rate and reduces heart rate. Excessive bradycardia can lead to dizziness, fatigue, hypotension, or syncope and requires careful monitoring and possible dose adjustment. C. Urinary retention is not typically associated with metoprolol use. This adverse effect is more commonly linked to anticholinergic medications or drugs that affect bladder contractility. Metoprolol primarily acts on cardiac receptors and does not significantly interfere with urinary function. D. Weight loss is not a characteristic adverse effect of metoprolol. Beta-blockers are more commonly associated with weight gain in some patients due to reduced metabolic rate and fatigue-related activity changes. Therefore, unexpected weight loss would suggest an unrelated condition rather than a direct medication effect.