Which side effect is associated with antihypertensive medications?

Bradycardia, or a slowed heart rate, is a known side effect of certain antihypertensive medications, particularly those that are classified as beta-blockers and some calcium channel blockers. These medications work by reducing the heart's workload and lowering blood pressure, which can lead to a decreased heart rate. This effect is often a desired outcome in patients who have hypertension or specific cardiovascular conditions, as it can contribute to reduced strain on the heart.

In contrast, while medications can lead to various side effects, the other options listed (nausea, constipation, and headache) are not as directly linked to the mechanism of action of antihypertensive drugs. Instead, they might be side effects of other medication classes or related to underlying health conditions rather than a direct consequence of taking antihypertensive medications. Understanding how specific categories of drugs impact physiological parameters like heart rate is essential for effective patient management.