A person has headache & profuse sweating. On examination his B.P is 200/120 mm Hg. Which of the following shoud not be used -a) Nifedipineb) Phenoxybenozamine c) Methyldopad) Labetalol
**Core Concept**
The patient is presenting with symptoms of a hypertensive crisis, which requires immediate management to prevent target organ damage. The combination of headache, profuse sweating, and severely elevated blood pressure suggests a severe and potentially life-threatening condition.
**Why the Correct Answer is Right**
Phenoxybenzamine is a non-selective alpha-blocker that is commonly used to manage pheochromocytoma, a tumor that secretes catecholamines and can cause severe hypertension. However, in the setting of a hypertensive crisis, the use of a non-selective alpha-blocker can lead to reflex tachycardia and potentially worsen cardiac output, making it a less desirable choice in this scenario. Instead, agents that can rapidly reduce blood pressure while minimizing the risk of tachycardia and cardiac ischemia are preferred.
**Why Each Wrong Option is Incorrect**
**Option A:** Nifedipine is a calcium channel blocker that can rapidly lower blood pressure, but its use in hypertensive emergencies is generally not recommended due to the risk of reflex tachycardia and potential for cardiac ischemia. However, it's not the best answer in this case.
**Option C:** Methyldopa is an alpha-2 adrenergic agonist that can lower blood pressure by reducing sympathetic outflow. It's not the best answer in this case.
**Option D:** Labetalol is a mixed alpha/beta-blocker that can rapidly lower blood pressure while minimizing the risk of tachycardia and cardiac ischemia, making it a suitable choice in this scenario.
**Clinical Pearl / High-Yield Fact**
In the management of hypertensive crises, it's essential to use agents that can rapidly lower blood pressure while minimizing the risk of tachycardia and cardiac ischemia. Non-selective alpha-blockers like phenoxybenzamine may not be the best choice in this scenario, as they can lead to reflex tachycardia and worsen cardiac output.
**Correct Answer:** B. Phenoxybenzamine