What antihypertensive medication is most associated with orthostatic hypotension symptoms?

The correct choice is associated with the mechanism by which certain antihypertensive medications can lead to orthostatic hypotension, particularly Prazosin, an alpha-1 adrenergic antagonist. This class of medications works by blocking alpha-1 receptors on vascular smooth muscle, resulting in vasodilation and decreased vascular resistance. When a patient shifts from a sitting or lying position to standing, the body typically compensates for gravity-related changes in blood flow to maintain blood pressure. However, Prazosin can impair this compensatory mechanism, leading to reduced systemic vascular resistance and causing a drop in blood pressure upon standing, which is experienced as orthostatic hypotension.

This side effect tends to be more pronounced with Prazosin compared to other antihypertensives like Metoprolol or Propranolol, which primarily focus on beta-adrenergic blocking and have different side effect profiles. Alfuzosin, primarily used for benign prostatic hyperplasia, can also cause orthostatic symptoms but is less commonly associated with them than Prazosin. Thus, the specific action of Prazosin on the alpha receptors is what distinctively ties it to the development of orthostatic hypotension symptoms.