What is the use of Hydralazine (Apresoline)?

From the Guidelines

Hydralazine is primarily used to treat high blood pressure and heart failure as a direct-acting vasodilator medication, with an initial dose of 10 mg via slow IV infusion for hypertensive emergencies, as stated in the 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 1.

Key Points

• Hydralazine works by relaxing the smooth muscle in blood vessel walls, causing them to widen and reduce blood pressure.
• The medication is used in cases of hypertensive emergencies, with a typical initial dose of 10 mg via slow IV infusion, which can be repeated every 4-6 hours as needed 1.
• Hydralazine is also used in combination with nitrates, such as isosorbide dinitrate, to reduce cardiac workload and improve heart function in patients with heart failure.
• Common side effects of hydralazine include headache, dizziness, flushing, palpitations, and nasal congestion.
• More serious concerns with hydralazine use include a lupus-like syndrome with long-term use, particularly at higher doses and in slow acetylators (especially women) 1.

Usage Considerations

• Patients should be monitored for development of positive antinuclear antibodies when taking hydralazine.
• Hydralazine should be used cautiously in patients with coronary artery disease, as it may cause reflex tachycardia.
• The medication is also used in pregnancy-related hypertension when needed, as it has a long safety record in pregnant women.
• Regular monitoring of blood pressure is essential when taking hydralazine to ensure proper dosing and effectiveness.

Dosage and Administration

• The typical starting dose for hypertension is 10-25 mg orally four times daily, which can be gradually increased to 50 mg four times daily if needed.
• For heart failure, hydralazine is often prescribed in combination with nitrates, such as isosorbide dinitrate, to reduce cardiac workload and improve heart function.
• Total daily doses of hydralazine should be <150 mg to avoid drug-induced systemic lupus erythematosus, as recommended in the resistant hypertension guideline 1.

From the FDA Drug Label

In hypertensive patients with normal kidneys who are treated with hydralazine, there is evidence of increased renal blood flow and a maintenance of glomerular filtration rate. The use of Hydralazine (Apresoline) is for hypertension treatment, as it has been shown to increase renal blood flow and maintain glomerular filtration rate in hypertensive patients with normal kidneys 2.

From the Research

Use of Hydralazine (Apresoline)

• Hydralazine is used to treat severe asymptomatic hypertension and hypertensive crises 3, 4, 5.
• It is a direct-acting vasodilator that lowers blood pressure by decreasing total peripheral resistance 6.
• Hydralazine can be administered orally or intravenously, with oral administration being the most common 3.
• It is often used in combination with other antihypertensive medications, such as beta-adrenergic blockers and diuretics 6.

Administration and Dosage

• The dosage of hydralazine varies depending on the patient's condition and the route of administration 4, 5.
• Intravenous hydralazine is typically administered in doses of 5-10 mg, repeated as needed to achieve the desired blood pressure reduction 4.
• Oral hydralazine is often prescribed in doses of 25-50 mg, taken 2-4 times a day 7.

Efficacy and Safety

• Hydralazine has been shown to be effective in reducing blood pressure in patients with hypertension 3, 4, 7.
• However, its use can be associated with side effects such as reflex tachycardia, hemolytic anemia, vasculitis, glomerulonephritis, and a lupus-like syndrome 7.
• Hydralazine should be used with caution in patients with certain medical conditions, such as heart failure or dissecting aortic aneurysm 5.