Hydralazine / Hydrochlorothiazide Dosage

Usual Adult Dose for Congestive Heart Failure

Initial dose: 1 capsule orally twice a day (the strength depending upon individual requirement following titration).

Maintenance dose: Should be adjusted to the lowest effective level. Higher daily HCTZ doses are not recommended. Daily hydralazine doses up to 200 mg can be given and are safe for use in most patients. Hydralazine doses up to 300 mg per day (75 mg four times a day) were used in the first Veterans Heart Failure Trial demonstrating a reduction of mortality when used in combination with nitrates in patients with chronic congestive heart failure.

While most patients respond to 200 mg of hydralazine per day or less, some "fast acetylators", are resistant, requiring 300 mg per day or more. Because up to 20% of patients who receive 400 mg per day or more develop a systemic lupus erythematosus syndrome, some experts recommend checking a patient's acetylator status before giving higher doses. Up to 70% of "resistant" patients are fast acetylators, in whom the dose can be relatively safely increased.

Usual Adult Dose for Hypertension

Initial dose: 1 capsule orally twice a day (the strength depending upon individual requirement following titration).

Maintenance dose: Should be adjusted to the lowest effective level. Higher daily HCTZ doses are not recommended. Daily hydralazine doses up to 200 mg can be given and are safe for use in most patients. Hydralazine doses up to 300 mg per day (75 mg four times a day) were used in the first Veterans Heart Failure Trial demonstrating a reduction of mortality when used in combination with nitrates in patients with chronic congestive heart failure.

While most patients respond to 200 mg of hydralazine per day or less, some "fast acetylators", are resistant, requiring 300 mg per day or more. Because up to 20% of patients who receive 400 mg per day or more develop a systemic lupus erythematosus syndrome, some experts recommend checking a patient's acetylator status before giving higher doses. Up to 70% of "resistant" patients are fast acetylators, in whom the dose can be relatively safely increased.

Renal Dose Adjustments

Hydrochlorothiazide is generally not effective in patients with creatinine clearance less than 25 mL/min. Use hydrochlorothiazide with caution in patients with severe renal disease.

Liver Dose Adjustments

Use hydrochlorothiazide with caution in patients with impaired hepatic function.

Precautions

Safety and effectiveness have not been established in pediatric patients (less than 18 years of age).

Dialysis

Data not available

Other Comments

Hydralazine-hydrochlorothiazide is not recommended or approved for the initial treatment of hypertension or any other condition. The dosage recommendation is made assuming that this patient is already taking the maximum recommended or tolerable daily dose of hydralazine.

Patients who fail to respond should be reminded to take hydralazine with food, which significantly enhances its bioavailability.

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Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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