ICU · Pharmacology
Antihypertensives — ACEi, ARB, CCB, Beta-blockers & Vasodilators
Also known as Antihypertensives · ACE inhibitor · ARB · Calcium channel blocker · Beta-blocker · Sodium nitroprusside · Glyceryl trinitrate · Labetalol · Nicardipine · Clevidipine · Esmolol · Hydralazine · Phentolamine · Nimodipine
Antihypertensives — by mechanism: the RAS (ACEi — the bradykinin cough; the ARB); the CCB (the dihydropyridine — the amlodipine; the non-DHP — the verapamil/diltiazem); the beta-blockers (metoprolol β1-selective, labetalol α+β, esmolol ultra-short); the vasodilators (the SNP — the cyanide toxicity; the GTN; the hydralazine); the alpha-blockers (phentolamine — pheochromocytoma); the centrally acting (the methyldopa, the clonidine); the diuretics (furosemide — acute pulmonary oedema). ICU drug selection by indication: aortic dissection (beta-blocker first), intracerebral haemorrhage (nicardipine/clevidipine), pre-eclampsia (labetalol/hydralazine/nifedipine), eclampsia (magnesium sulfate).
Checked against its sources on 3 Sept 2026
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Red flags
- Sodium nitroprusside releases cyanide — high/prolonged dosing or renal/hepatic impairment causes cyanide toxicity (rising lactate, metabolic acidosis, AV-O2 narrowing). Antidote: sodium thiosulfate ± hydroxocobalamin
- ACEi/ARB are contraindicated in pregnancy (ACE fetopathy) and can cause AKI in bilateral renal artery stenosis
- Aortic dissection: give the BETA-BLOCKER first to lower dP/dt, BEFORE any pure vasodilator — vasodilator alone causes reflex tachycardia and raises shear stress
- Phentolamine (alpha-blocker) is first-line for pheochromocytoma crisis — never give a beta-blocker alone (unopposed alpha stimulation → catastrophic hypertension)
- Sublingual nifedipine is contraindicated in pregnancy — causes precipitous, uncontrollable BP falls
- Clevidipine and nicardipine are formulated in lipid emulsion — contraindicated in egg/soy allergy and defective lipid metabolism
Meet the patient
A 64-year-old hypertensive smoker arrives at 3am with sudden tearing interscapular pain, BP 220/125 right arm, 195/110 left arm, HR 118. CT confirms a type B aortic dissection. The vascular team asks you to control the pressure while they assess.[1]
The question that decides the next hour is the question that decides every hypertensive emergency: which agent, for which indication, at what target, over what rate of fall, avoiding which toxicity? You will meet this at 3am — for a dissection, an ICH, a pre-eclamptic seizure, a pheochromocytoma crisis, or a cocaine-intoxicated patient. The drug is matched to the target organ, not to the BP number.[1][9]
References37ShowHide
- [1]Hagan PG, Nienaber CA, Isselbacher EM, et al. The International Registry of Acute Aortic Dissection (IRAD): new insights into an old disease JAMA, 2000.PMID 10685714
- [2]Anderson CS, Heeley E, Huang Y, et al. Rapid blood-pressure lowering in patients with acute intracerebral hemorrhage N Engl J Med, 2013.PMID 23713578
- [3]Qureshi AI, Palesch YY, Barsan WG, et al. Intensive Blood-Pressure Lowering in Patients with Acute Cerebral Hemorrhage N Engl J Med, 2016.PMID 27276234
- [4]Pickard JD, Murray GD, Illingworth R, et al. Effect of oral nimodipine on cerebral infarction and outcome after subarachnoid haemorrhage: British aneurysm nimodipine trial BMJ, 1989.PMID 2496789
- [5]Peacock WF 4th, Varon J, Ebrahimi R, et al. Clevidipine for severe hypertension in acute heart failure: a VELOCITY trial analysis Congest Heart Fail, 2010.PMID 20412469
- [6]Altman D, Carroli G, Duley L, et al. Do women with pre-eclampsia, and their babies, benefit from magnesium sulphate? The Magpie Trial: a randomised placebo-controlled trial Lancet, 2002.PMID 12057549
- [7]Williams B, Mancia G. Ten Commandments of the 2018 ESC/ESH HTN Guidelines on Hypertension in Adults Eur Heart J, 2018.PMID 30990869
- [8]Whelton PK, Carey RM, Aronow WS, et al. 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines Hypertension, 2018.PMID 29133356
- [9]van den Born BJ, Beutler JJ, Gaillard CA, et al. Dutch guideline for the management of hypertensive crisis -- 2010 revision Neth J Med, 2011.PMID 21646675
- [10]Cannon CM, Levy P, Baumann BM, et al. Intravenous nicardipine and labetalol use in hypertensive patients with signs or symptoms suggestive of end-organ damage in the emergency department: a subgroup analysis of the CLUE trial BMJ Open, 2013.PMID 23535700
- [11]Liu-DeRyke X, Levy PD, Parker D Jr, et al. A prospective evaluation of labetalol versus nicardipine for blood pressure management in patients with acute stroke Neurocrit Care, 2013.PMID 23760911
- [12]Talbert RL. The challenge of blood pressure management in neurologic emergencies Pharmacotherapy, 2006.PMID 16863478
- [13]Wright JT Jr, Williamson JD, Whelton PK, et al. A Randomized Trial of Intensive versus Standard Blood-Pressure Control N Engl J Med, 2015.PMID 26551272
- [14]Abalos E, Duley L, Steyn DW, Gialdini C. Antihypertensive drug therapy for mild to moderate hypertension during pregnancy Cochrane Database Syst Rev, 2018.PMID 30277556
- [15]Eisenhofer G, Lenders JW, Linehan WM, et al. Plasma normetanephrine and metanephrine for detecting pheochromocytoma in von Hippel-Lindau disease and multiple endocrine neoplasia type 2 N Engl J Med, 1999.PMID 10369850
- [16]Elliott WJ. Clinical features and management of selected hypertensive emergencies J Clin Hypertens (Greenwich), 2004.PMID 15470289
- [17]Khan NN, Zurayyir EJ, Alghamdi AM, et al. Management Strategies for Hypertensive Crisis: A Systematic Review Cureus, 2024.PMID 39262522
- [18]Krenz JR, O'Brien ME, Lee J, et al. Evaluation of esmolol for heart rate control in patients with acute aortic dissection Am J Emerg Med, 2021.PMID 32354528
- [19]Tempe DK, Mulchandani P, Tandon MS, et al. Control of tachycardia and hypertension following coronary artery bypass graft surgery: efficacy and haemodynamic effects of esmolol Indian Heart J, 1999.PMID 10624069
- [20]Zedigh C, Alho A, Hammar E, et al. Aspects on the intensity and the relief of pain in the prehospital phase of acute coronary syndrome: experiences from a randomized clinical trial Coron Artery Dis, 2010.PMID 20124885
- [21]Vigil-De Gracia P, Lasso M, Ruiz E, et al. Severe hypertension in pregnancy: hydralazine or labetalol. A randomized clinical trial Eur J Obstet Gynecol Reprod Biol, 2006.PMID 16621226
- [22]Myklejord DJ. Undiagnosed pheochromocytoma: the anesthesiologist nightmare Clin Med Res, 2004.PMID 15931336
- [23]Liu C, Lv Q, Chen X, et al. Preoperative selective vs non-selective α-blockade in PPGL patients undergoing adrenalectomy Endocr Connect, 2017.PMID 28986400
- [24]Koga M, Arihiro S, Hasegawa Y, et al. Intravenous nicardipine dosing for blood pressure lowering in acute intracerebral hemorrhage: the Stroke Acute Management with Urgent Risk-factor Assessment and Improvement-Intracerebral Hemorrhage study J Stroke Cerebrovasc Dis, 2014.PMID 25314943
- [25]Kenyon KW. Clevidipine: an ultra short-acting calcium channel antagonist for acute hypertension Ann Pharmacother, 2009.PMID 19584385
- [26]Henry K, Pelsue B, Hartman H, et al. Low versus high dosing strategies of intravenous nitroglycerin for the management of sympathetic crashing acute pulmonary edema Am J Emerg Med, 2025.PMID 40834833
- [27]Pilmer BL, Green JA, Panacek EA, et al. Fenoldopam mesylate versus sodium nitroprusside in the acute management of severe systemic hypertension J Clin Pharmacol, 1993.PMID 8103527
- [28]Broderick KE, Balasubramanian M, Chan A, et al. The cobalamin precursor cobinamide detoxifies nitroprusside-generated cyanide Exp Biol Med (Maywood), 2007.PMID 17526771
- [29]Udeh CI, Ting M, Arango M, et al. Delayed presentation of nitroprusside-induced cyanide toxicity Ann Thorac Surg, 2015.PMID 25841829
- [30]Morris AA, Page RL 2nd, Baumgartner LJ, et al. Thiocyanate Accumulation in Critically Ill Patients Receiving Nitroprusside Infusions J Intensive Care Med, 2017.PMID 27435907
- [31]Saldana S, Breslin J 2nd, Hanify J, et al. Comparison of Clevidipine and Nicardipine for Acute Blood Pressure Reduction in Hemorrhagic Stroke Neurocrit Care, 2022.PMID 34904214
- [32]The Eclampsia Trial Collaborative Group. Which anticonvulsant for women with eclampsia? Evidence from the Collaborative Eclampsia Trial Lancet, 1995.PMID 7769899
- [33]Brookfield KF, Tuel K, Rincon M, et al. Alternate Dosing Protocol for Magnesium Sulfate in Obese Women With Preeclampsia: A Randomized Controlled Trial Obstet Gynecol, 2020.PMID 33156201
- [34]Misra M, Chembale J, Kankane A. Evaluation of the efficacy, safety and tolerability of intravenous enalaprilat in the treatment of grade III essential hypertension in Indian patients Indian Heart J, 2004.PMID 15129797
- [35]Rose JC, Mayer SA. Optimizing blood pressure in neurological emergencies Neurocrit Care, 2004.PMID 16174926
- [36]Varon J. Treatment of acute severe hypertension: current and newer agents Drugs, 2008.PMID 18257607
- [37]van den Born BH, Lip GYH, Brguljan-Hitij J, et al. ESC Council on hypertension position document on the management of hypertensive emergencies Eur Heart J Cardiovasc Pharmacother, 2019.PMID 30165588