Which medication is commonly used to treat a hypertensive crisis?

Nitroprusside is commonly employed in treating hypertensive crises due to its rapid onset and potent vasodilatory effects. In a hypertensive crisis, blood pressure can rise to dangerously high levels, necessitating immediate intervention to prevent complications such as stroke or heart failure. Nitroprusside works by dilating both arterioles and venules, leading to a significant decrease in systemic vascular resistance and, consequently, blood pressure. This effect can be closely monitored and adjusted, making it particularly useful in acute settings where precise control over blood pressure is critical.

Other medications listed, while they have their own therapeutic uses, do not provide the same immediacy in managing severe hypertension. For instance, while minoxidil and hydralazine are effective antihypertensives, they generally take longer to act and are not typically used in acute crisis situations. Amlodipine, a calcium channel blocker, is primarily used for chronic management of hypertension and does not work quickly enough for a hypertensive emergency. Therefore, nitroprusside stands out as the most appropriate choice for acute treatment of hypertensive crises.