From the Guidelines
Yes, isosorbide dinitrate (Isordil) is used in the treatment of congestive heart failure (CHF), particularly in combination with hydralazine, especially in African American patients who may benefit most from this combination. The most recent and highest quality study, 1, recommends the combination of hydralazine and isosorbide dinitrate for African Americans with NYHA class III-IV HFrEF on guideline-directed medical therapy.
Key Points
- Isosorbide dinitrate is typically prescribed for patients with heart failure, often in combination with hydralazine.
- The usual dosage of isosorbide dinitrate for heart failure ranges from 20-40 mg orally three to four times daily, though dosing may be individualized based on patient response.
- Headaches are a common side effect that often diminishes with continued use.
- Patients should take the medication at evenly spaced intervals throughout the day, with the last dose typically taken no later than 7 PM to avoid nighttime hypotension.
- Isosorbide dinitrate works as a nitrate vasodilator that releases nitric oxide, causing blood vessels to relax and reducing the workload on the heart.
- Tolerance can develop with continuous use, so physicians sometimes recommend a nitrate-free interval of 10-12 hours, usually overnight.
Mechanism of Action
Isosorbide dinitrate releases nitric oxide, causing blood vessels to relax and reducing the workload on the heart. This decreases both preload and afterload, improving cardiac output and reducing symptoms of heart failure such as shortness of breath and exercise intolerance.
Special Considerations
The combination of hydralazine and isosorbide dinitrate can be useful in patients with HFrEF who cannot be given ACE inhibitors or ARBs, as stated in 1. However, the selection of this combination should be individualized, taking into account the patient's specific needs and medical history.
From the FDA Drug Label
The benefits of immediate-release oral isosorbide dinitrate in patients with acute myocardial infarction or congestive heart failure have not been established. If one elects to use isosorbide dinitrate in these conditions, careful clinical or hemodynamic monitoring must be used to avoid the hazards of hypotension and tachycardia
- Isosorbide dinitrate is not recommended for use in congestive heart failure (CHF) due to the lack of established benefits and potential risks of hypotension and tachycardia 2.
From the Research
Use of Isosorbide Dinitrate in Congestive Heart Failure (CHF)
- Isosorbide dinitrate is used in the treatment of congestive heart failure (CHF), particularly in combination with hydralazine 3, 4, 5, 6, 7.
- The combination of hydralazine and isosorbide dinitrate has been shown to have arterial and venous vasodilating properties, which can help decrease preload and afterload, and improve left ventricular ejection fraction 3.
- Studies have demonstrated that isosorbide dinitrate can be effective in reducing symptoms and improving exercise tolerance in patients with CHF 4, 5, 6.
- The use of isosorbide dinitrate in combination with hydralazine has been shown to be beneficial in patients with heart failure with reduced ejection fraction (HFrEF) who cannot receive angiotensin-converting enzyme inhibitors or angiotensin receptor blockers due to intolerance or contraindication 3.
- Isosorbide dinitrate has also been shown to have antioxidant properties and can improve NO bioavailability, which can be beneficial in the treatment of CHF 3.
Benefits of Isosorbide Dinitrate in CHF
- Decreases preload and afterload 3, 4, 6
- Improves left ventricular ejection fraction 3, 7
- Increases exercise tolerance 4, 5
- Reduces symptoms of CHF 4, 5, 6
- Has antioxidant properties and improves NO bioavailability 3
Combination Therapy with Hydralazine
- The combination of hydralazine and isosorbide dinitrate has been shown to be effective in the treatment of CHF 3, 4, 5, 7
- This combination has been shown to be beneficial in patients with HFrEF who cannot receive angiotensin-converting enzyme inhibitors or angiotensin receptor blockers due to intolerance or contraindication 3
- The combination of hydralazine and isosorbide dinitrate has been shown to improve hemodynamic parameters and reduce morbidity and mortality in patients with CHF 5, 7