From the Guidelines
The recommended dosing for Bidil (hydralazine and isosorbide dinitrate) in heart failure starts at one tablet containing 20 mg isosorbide dinitrate and 37.5 mg hydralazine three times daily, with a target dose of 40 mg isosorbide dinitrate and 75 mg hydralazine three times daily, as indicated in the 2022 AHA/ACC/HFSA guideline for the management of heart failure 1.
Key Considerations
- The initial daily dose is 20 mg isosorbide dinitrate and 37.5 mg hydralazine three times daily.
- The target dose is 40 mg isosorbide dinitrate and 75 mg hydralazine three times daily, for a total daily dose of 120 mg isosorbide dinitrate and 225 mg hydralazine.
- Titration should occur gradually over 3-5 days as tolerated, monitoring for side effects such as headache, dizziness, and hypotension.
- Bidil should be taken with food to reduce the risk of orthostatic hypotension, and doses should be spaced at least 6 hours apart.
Mechanism of Action
- Hydralazine is a vasodilator that reduces afterload.
- Isosorbide dinitrate increases nitric oxide availability, improving endothelial function.
Clinical Context
- Bidil is specifically approved for heart failure treatment in self-identified Black patients.
- It is typically added to standard heart failure therapy, including ACE inhibitors, beta-blockers, and diuretics, rather than replacing these medications.
- Regular blood pressure monitoring is essential during dose titration and maintenance therapy, as supported by the guidelines 1.
From the Research
Dosing for Bidil (Hydralazine and Isosorbide Dinitrate) in Heart Failure
- The dosing for Bidil, a combination of hydralazine and isosorbide dinitrate, is not explicitly stated in terms of a specific dosage regimen for heart failure in the provided studies.
- However, the studies mention the use of a fixed-dose combination of 20 mg of isosorbide dinitrate and 37.5 mg of hydralazine hydrochloride, as seen in the African-American Heart Failure Trial 2.
- Other studies refer to dosages of isosorbide dinitrate 40 mg QID and hydralazine 75 mg QID 3, but these are not directly linked to the Bidil formulation.
- The combination of hydralazine and isosorbide dinitrate has been shown to have beneficial effects in patients with heart failure, including decreased mortality and improved quality of life 4, 3.
- The use of Bidil is currently indicated for the treatment of heart failure as an adjunct to standard therapy in black patients 4, with the combination of isosorbide dinitrate and hydralazine demonstrating a 43% reduction in mortality when compared with placebo in the African-American Heart Failure Trial 2, 4.