Examples

Nitrates

How It Works

Vasodilators work on different substances in the body to help widen (dilate) blood vessels. It is easier for the heart to pump blood if the blood vessels are widened.

Why It Is Used

Vasodilators are often combined with other medicines to treat heart failure. Certain vasodilators may be used as an alternative to angiotensin-converting enzyme (ACE) inhibitors if ACE inhibitors cannot be tolerated.

How Well It Works

For heart failure, hydralazine and isosorbide dinitrate are taken together. When taken with other medicines to treat heart failure, vasodilators may relieve symptoms and lower premature death rates. This benefit was shown in African Americans but has not been shown in other groups of people.¹

Side Effects

The most common side effect is low blood pressure, which may cause symptoms of dizziness, weakness, or fainting. People who have low blood pressure when they start therapy will generally be started with a low dose and may need close monitoring to avoid reducing blood pressure too much.

Long-term use of these medicines is associated with fluid retention (with hydralazine) and loss of effectiveness (development of tolerance) with nitrates. For these reasons, their use may be limited.

Nitrates may cause headaches.

See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)

What To Think About

Vasodilator drugs seldom are used alone to treat heart failure.

If you are taking nitrates, do not use erection-enhancing medicines such as sildenafil (Viagra), tadalafil (Cialis), or vardenafil (Levitra). Do not take a nitrate and an erection-enhancing medicine together because you can have very low blood pressure, which can lead to death.

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