Drug of choice for hypertensive crisis?

Appeared in: JIPMER Pondicherry NO - 2022

Explanation

Sodium nitroprusside is a powerful, direct-acting parenteral vasodilator specifically used for treating hypertensive emergencies.
It acts on both arterioles (reducing afterload) and venules (reducing preload), leading to a rapid and significant drop in blood pressure.
Its action begins almost instantly and has a very short duration of 1-10 minutes after stopping the infusion, which allows for precise, titratable control of blood pressure in a critical care setting.

Option A: Phentolamine is an alpha-adrenergic blocker, not a first-line agent for general hypertensive crises.
Option B: Phenytoin is an anticonvulsant medication used to treat and prevent seizures (epilepsy).
Option C: Diazepam is a benzodiazepine, which is primarily used as an anxiolytic (anti-anxiety), muscle relaxant, and anticonvulsant.

Clinical Relevance

Nursing practice connection: Knowing Pharmacological management of hypertensive emergencies helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Management of a hypertensive emergency requires an ICU setting with continuous, invasive arterial blood pressure monitoring due to the potency of drugs like sodium nitroprusside.
Nurses must be vigilant for signs of cyanide and thiocyanate toxicity (e.g., tinnitus, altered mental status, metabolic acidosis) with prolonged nitroprusside infusion, especially in patients with renal impairment.
The IV bag and tubing for sodium nitroprusside must be wrapped in an opaque material (like aluminum foil) to protect the drug from light, which causes it to degrade into toxic byproducts.

How to Approach the Question

First, identify the clinical condition presented in the question: a 'hypertensive crisis'. This is a medical emergency requiring immediate intervention.
Next, recall the classes of drugs used for rapid, parenteral (IV) blood pressure reduction. These are typically potent vasodilators or adrenergic blockers.
Evaluate each option based on its primary pharmacological class and indication.
Recognize Sodium Nitroprusside as a classic, powerful IV vasodilator used for this exact purpose.
Eliminate Phenytoin and Diazepam, as they are anticonvulsant and anxiolytic drugs, respectively, and do not primarily treat hypertension.
Identify Phentolamine as a specialized alpha-blocker for specific situations like pheochromocytoma, not the general drug of choice for all hypertensive crises.

Concept Tested & Keywords

Q_KhDSgcNXD6QcUGmzOpyJ

E6 Pharmacology Katzung 16e p. 279-281

E6 Pharmacology KD Tripathi Essentials 9e Part 2 p. 245-247

E6 Obstetrics Williams p. 33-53

Practise the full JIPMER Pondicherry NO - 2022

Attempt every question from this paper in a timed mock, then review the full solution for each one.