Which of the following medications can be used to treat hypertensive urgency?

Clonidine is a medication that can effectively treat hypertensive urgency due to its ability to rapidly lower blood pressure. It acts as an alpha-2 adrenergic agonist, leading to decreased sympathetic outflow and, consequently, reduced peripheral vascular resistance. This mechanism allows for a swift onset of action, making clonidine particularly useful in situations where urgent blood pressure control is needed.

In contrast, the other medications listed have different roles or timelines in managing hypertension. Lisinopril is an ACE inhibitor primarily used for long-term blood pressure management and is not typically recommended for urgent situations due to its slower onset. Metoprolol, a beta-blocker, can help manage hypertension but is also not the first choice for hypertensive urgency as it may take time for the effects to become significant. Hydrochlorothiazide, a thiazide diuretic, is generally used for chronic management of hypertension rather than immediate reductions in blood pressure. Therefore, clonidine stands out as the most appropriate choice for treating hypertensive urgency.