What is the first line treatment to decrease blood pressure (BP) in an adult patient with acute hypertension in a hospital setting?

First-Line Treatment for Acute Hypertension in Hospital Setting

For most hypertensive emergencies in hospitalized adults, intravenous labetalol or nicardipine should be used as first-line therapy, with the specific choice dependent on the type of end-organ damage present. 1

General Approach to Hypertensive Emergencies

The 2019 European Society of Cardiology guidelines emphasize that labetalol and nicardipine are widely available throughout Europe and should be included in the essential drug list of each hospital with an emergency room or intensive care unit, as most hypertensive emergencies can be treated with either agent. 1

Blood Pressure Reduction Targets

• For most hypertensive emergencies without compelling conditions: Reduce systolic blood pressure by no more than 25% within the first hour, then if stable, to 160/100 mmHg within the next 2-6 hours, and cautiously to normal during the following 24-48 hours. 1

• For compelling conditions (aortic dissection, severe preeclampsia/eclampsia, pheochromocytoma crisis): Reduce systolic blood pressure to <140 mmHg during the first hour, and to <120 mmHg in aortic dissection. 1

First-Line Agents by Clinical Presentation

Labetalol as First-Line

Labetalol is the preferred first-line agent for:

• Malignant hypertension with or without thrombotic microangiopathy or acute renal failure (target: MAP reduction of 20-25% over several hours) 1
• Hypertensive encephalopathy (target: immediate MAP reduction of 20-25%) - labetalol preserves cerebral blood flow relatively intact compared to nitroprusside and does not increase intracranial pressure 1
• Acute ischemic stroke with BP >220/120 mmHg (target: MAP reduction of 15% within 1 hour) 1
• Acute ischemic stroke requiring thrombolysis with BP >185/110 mmHg (target: MAP reduction of 15% within 1 hour) 1
• Acute hemorrhagic stroke with systolic BP >180 mmHg (target: systolic BP 130-180 mmHg immediately) 1
• Eclampsia and severe preeclampsia/HELLP syndrome (target: systolic BP <160 mmHg and diastolic BP <105 mmHg immediately) - used with magnesium sulfate 1

Labetalol dosing: 20-80 mg IV bolus every 10 minutes 1

Nicardipine as First-Line Alternative

Nicardipine is equally effective and serves as first-line or alternative for most hypertensive emergencies except acute heart failure. 1

Nicardipine dosing: Initial 5 mg/h IV infusion, increasing every 5 minutes by 2.5 mg/h to maximum 15 mg/h. 1, 2

• No dose adjustment needed for elderly patients 1
• Contraindicated in advanced aortic stenosis 1
• Mean time to therapeutic response is approximately 12-77 minutes depending on severity 2

Nitrates as First-Line for Cardiac Emergencies

For acute coronary events: Nitroglycerin is first-line (target: systolic BP <140 mmHg immediately) 1

For acute cardiogenic pulmonary edema: Nitroprusside or nitroglycerin with loop diuretic (target: systolic BP <140 mmHg immediately) 1

Beta-Blockers Plus Nitrates for Aortic Dissection

For acute aortic disease: Esmolol combined with nitroprusside or nitroglycerin is first-line (target: systolic BP <120 mmHg and heart rate <60 bpm immediately) 1

Critical Pitfalls to Avoid

Agents to Avoid as First-Line

Hydralazine should NOT be used as first-line for most hypertensive emergencies due to:

• Unpredictable response and prolonged duration of action (2-4 hours) 1, 3
• Can cause reflex tachycardia 3
• The ACC/AHA guidelines explicitly state hydralazine "is not a desirable first-line agent for acute treatment in most patients" 3
• Exception: Hydralazine remains acceptable for eclampsia/severe preeclampsia as second-line 3

Sodium nitroprusside should be used with extreme caution:

• Risk of cyanide toxicity with prolonged use or high doses (≥4-10 mcg/kg/min or duration >30 minutes) 1
• Requires intra-arterial BP monitoring to prevent "overshoot" 1
• Some experts recommend avoiding it entirely due to toxicity concerns 4, 5

Immediate-release nifedipine, sublingual medications, and nitroglycerin (except for acute coronary syndrome/pulmonary edema) should be avoided as first-line due to unpredictable effects and adverse outcomes. 4, 5

Special Population Considerations

In patients with bradycardia: Avoid labetalol; use nicardipine or clevidipine instead as they do not worsen heart rate. 6

In acute intracerebral hemorrhage presenting within 6 hours with SBP 150-220 mmHg: Immediate lowering of SBP to <140 mmHg is NOT beneficial and can be potentially harmful (Class III: Harm recommendation). 1

In patients with impaired cardiac, hepatic, or renal function: Close monitoring is required when titrating any IV antihypertensive. 2

Practical Administration Points

• Use continuous IV infusion via central line or large peripheral vein for nicardipine 2
• Change infusion site every 12 hours if using peripheral vein 2
• Titrate to effect: For gradual BP reduction with nicardipine, increase by 2.5 mg/hr every 15 minutes; for more rapid reduction, titrate every 5 minutes 2
• Monitor for hypotension or tachycardia: If occurs, discontinue infusion, allow stabilization, then restart at lower doses (3-5 mg/hr for nicardipine) 2