Phentolamine is the Most Appropriate Medication
For cocaine-induced hypertensive emergency with severe hypertension (230/120), phentolamine is the most appropriate choice among the options provided, as it is an alpha-blocker specifically indicated for hypertensive emergencies caused by catecholamine excess. 1
Why Phentolamine (Option D)
Phentolamine directly reverses cocaine-induced coronary artery vasospasm and hypertension through alpha-adrenergic blockade, addressing the underlying mechanism of cocaine toxicity 2, 1
The American Heart Association guidelines specifically identify phentolamine as a reasonable agent for severe cocaine-associated cardiovascular toxicity 2
Initial dosing is 5 mg IV bolus, with additional boluses every 10 minutes as needed to achieve blood pressure control 1
Phentolamine demonstrated reversal of cocaine-induced coronary artery vasospasm in the cardiac catheterization laboratory 2
Why NOT the Other Options
Esmolol (Option B) - Contraindicated
Pure beta-blockers like esmolol are contraindicated in cocaine toxicity due to the risk of unopposed alpha-adrenergic stimulation, which can paradoxically worsen hypertension and coronary vasospasm 2, 1, 3
A retrospective case series of 7 patients with cocaine toxicity treated with esmolol showed no consistent improvement in hypertension or tachycardia, and 3 of 7 patients developed adverse effects including worsening hypertension 2
Historical case reports document propranolol-induced hypertensive crisis in cocaine intoxication, with blood pressure increases requiring nitroprusside rescue 3
The American College of Cardiology explicitly recommends avoiding pure beta-blockers in cocaine toxicity 1
Isoproterenol (Option A) - Worsens Toxicity
Isoproterenol is a beta-agonist that would exacerbate cocaine's sympathomimetic effects, worsening tachycardia and hypertension 4
This represents the opposite of appropriate treatment for cocaine overdose
N-Acetylcysteine (Option C) - No Role
N-acetylcysteine has no established role in treating cocaine-induced hypertension or cardiovascular toxicity 2, 1, 5
This medication is used for acetaminophen overdose and as a mucolytic, not for sympathomimetic toxicity
Optimal Treatment Algorithm
First-Line: Benzodiazepines
Before or concurrent with phentolamine, administer benzodiazepines (lorazepam 2-4 mg IV or diazepam 5-10 mg IV) to reduce central nervous system stimulation and sympathetic drive 1
Benzodiazepines address agitation, anxiety, and the underlying catecholamine surge, and may partially control hypertension 2, 1
Second-Line: Add Vasodilator
If severe hypertension persists after benzodiazepines, add phentolamine as described above 1
Alternative vasodilators include calcium channel blockers (nicardipine, clevidipine) or nitroglycerin, though these are not among the answer choices 1, 5
Additional Considerations
Monitor for wide-complex tachycardia, which may require sodium bicarbonate due to cocaine's sodium channel blocking effects 1
Assess for hyperthermia, which requires rapid cooling as it can be life-threatening 1
Establish continuous cardiac monitoring and IV access for all cocaine overdose patients 1
Critical Pitfall to Avoid
The most dangerous error would be selecting esmolol (Option B), as pure beta-blockade in cocaine toxicity can precipitate severe hypertensive crisis through unopposed alpha-adrenergic vasoconstriction. 2, 1, 3, 6 This phenomenon has been documented in multiple case reports and is consistently cited as a contraindication in current guidelines. Even mixed beta/alpha blockers like labetalol should only be used after alpha blockade is established, as labetalol's beta-blocking effects are more potent than its alpha-blocking properties 2, 7