Hydralazine Dosing Protocol for Acute Blood Pressure Control

Intravenous Administration for Acute Hypertension

The American College of Cardiology recommends hydralazine as 10-20 mg IV bolus, repeated every 4-6 hours as needed, for acute blood pressure control in hospitalized patients, though it is not recommended as a first-line agent due to unpredictable response and risk of hypotension 1
The hypotensive effect of hydralazine lasts 2-4 hours, making response timing unpredictable 1
Repeat dosing of hydralazine should be based on blood pressure response, with the same dose repeated every 4-6 hours as needed 1

The European Heart Journal recommends nicardipine (5-15 mg/h IV infusion, titrated every 15-30 minutes) as a preferred alternative for acute blood pressure control, providing more predictable, titratable control 2
The European Heart Journal also recommends labetalol (0.25-0.5 mg/kg IV bolus or 2-4 mg/min infusion) as a preferred alternative when tachycardia is present, but contraindicated with bradycardia or heart failure 2
Clevidipine (2 mg/h IV infusion, increased every 2 minutes) is another preferred alternative, offering rapid onset and offset for precise control 2

The American College of Cardiology recommends hydralazine in combination with isosorbide dinitrate for mortality benefit in heart failure with reduced ejection fraction, with a target dose of 75 mg hydralazine/40 mg isosorbide dinitrate three times daily 3, 4, 5
The combination of hydralazine and isosorbide dinitrate provides a 43% relative risk reduction in mortality with NNT of 7 for preventing all-cause mortality over 36 months 3, 4

The American College of Cardiology recommends never using hydralazine as first-line for hypertensive emergencies, reserving it for situations where other agents are contraindicated 1