What is the recommended dosing for hydralazine (direct vasodilator) in this patient?

From the Guidelines

The recommended dosing for hydralazine in this patient is 100-200 mg/day, administered in 2 or 3 divided doses. According to 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, hydralazine is a direct vasodilator that can be used to treat hypertension. The usual dose range for hydralazine is 100-200 mg/day, administered in 2 or 3 divided doses.

Key Considerations

• Hydralazine is associated with sodium and water retention and reflex tachycardia, and should be used with a diuretic and beta blocker 1.
• Hydralazine is also associated with drug-induced lupus-like syndrome at higher doses 1.
• The dose of hydralazine may need to be adjusted based on the patient's blood pressure response and the development of side effects.
• Blood pressure should be monitored regularly after initiation of hydralazine, with particular attention during the first 24-48 hours when the hypotensive effect is most pronounced.
• Common side effects of hydralazine include headache, tachycardia, and fluid retention, which may require concurrent administration of a beta-blocker and diuretic.

Monitoring and Adjustments

• Regular monitoring of blood pressure and adjustment of the dose as needed to achieve optimal blood pressure control.
• Monitoring for signs and symptoms of drug-induced lupus-like syndrome, particularly in slow acetylators.
• Adjustment of the dose or addition of other medications as needed to manage side effects.

From the FDA Drug Label

Dosage & Administration When there is urgent need, therapy in the hospitalized patient may be initiated intramuscularly or as a rapid intravenous bolus injection directly into the vein. Hydralazine hydrochloride injection should be used only when the drug cannot be given orally. The usual dose is 20 to 40 mg, repeated as necessary The recommended dosing for hydralazine is 20 to 40 mg, repeated as necessary, with certain patients (especially those with marked renal damage) possibly requiring a lower dose 2.

• The dose should be adjusted based on frequent blood pressure checks.
• Patients can usually be transferred to oral hydralazine within 24 to 48 hours.

From the Research

Hydralazine Dosing

• The recommended dosing for hydralazine varies depending on the patient's condition and the route of administration.
• For intravenous administration, a dose of 10-20 mg per dose is commonly used 3.
• In some cases, hydralazine is administered orally, with doses ranging from 25 mg to 100 mg, given twice or three times a day 4, 5.
• A study on hydralazine once daily in hypertension found that a 200 mg once-daily dose was not sufficient to maintain blood pressure control for 24 hours, and that twice-daily administration was more effective 6.
• Another study found that intravenous hydralazine was often used in non-urgent cases of hypertension in hospitalized patients, with a mean dose of 11.4 ± 4.3 mg, but that its use was often unjustified and associated with hypotension 7.

Key Considerations

• The dosing of hydralazine should be individualized based on the patient's response and tolerance.
• Close monitoring of blood pressure and heart rate is necessary when administering hydralazine, especially in hospitalized patients.
• The use of intravenous hydralazine should be reserved for urgent hypertensive conditions, and its use in non-urgent cases should be carefully evaluated 3, 7.