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.
Vasodilators can improve heart failure symptoms by:
Dilating coronary arteries. This can help more blood reach your heart muscle.
Dilating leg veins. This can lower the amount of blood returning to the heart and limit the buildup of fluid in your lungs.
Dilating systemic arteries. Systemic arteries are blood vessels that carry blood to the rest of the body (excluding the heart and lungs). By dilating these arteries, vasodilators may relieve some of the work your heart needs to do.
Dilating pulmonary arteries. Dilating the arteries of the lungs (pulmonary arteries) also reduces the amount of work your heart needs to do.
Why It Is Used
Vasodilators are often combined with other medicines to treat heart failure. Hydralazine taken with a nitrate may be used as an alternative to angiotensin-converting enzyme (ACE) inhibitors if ACE inhibitors cannot be tolerated.1
How Well It Works
For heart failure, hydralazine is typically used along with a nitrate.
If you take hydralazine with a nitrate, you will also take other medicines for heart failure such as ACE inhibitors and beta-blockers. This combination of medicines may help relieve symptoms and lower the risk of early death. This benefit has been shown in African Americans but has not been shown in other groups of people.2
All medicines have side effects. But many people don't feel the side effects, or they are able to deal with them. Ask your pharmacist about the side effects of each medicine you take. Side effects are also listed in the information that comes with your medicine.
Here are some important things to think about:
- Usually the benefits of the medicine are more important than any minor side effects.
- Side effects may go away after you take the medicine for a while.
- If side effects still bother you and you wonder if you should keep taking the medicine, call your doctor. He or she may be able to lower your dose or change your medicine. Do not suddenly quit taking your medicine unless your doctor tells you to.
Call911or other emergency services right away if you have:
Call your doctor right away if you have:
Common side effects of this medicine include:
Dizziness or lightheadedness.
- Flushing, or feeling warm, in the face and neck.
- Swelling from fluid buildup.
See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)
What To Think About
Do not take an erection-enhancing medicine such as sildenafil (Viagra), tadalafil (Cialis), or vardenafil (Levitra) if you are taking a nitrate. Combining these two drugs can cause a life-threatening drop in blood pressure.
Medicine is one of the many tools your doctor has to treat a health problem. Taking medicine as your doctor suggests will improve your health and may prevent future problems. If you don't take your medicines properly, you may be putting your health (and perhaps your life) at risk.
There are many reasons why people have trouble taking their medicine. But in most cases, there is something you can do. For suggestions on how to work around common problems, see the topic Taking Medicines as Prescribed.
For tips on taking medicine for heart failure, see:
Heart Failure: Taking Medicines Properly.
Advice for women
If you are pregnant, breast-feeding, or planning to get pregnant, do not use any medicines unless your doctor tells you to. Some medicines can harm your baby. This includes prescription and over-the-counter medicines, vitamins, herbs, and supplements. And make sure that all your doctors know that you are pregnant, breast-feeding, or planning to get pregnant.
Follow-up care is a key part of your treatment and safety. Be sure to make and go to all appointments, and call your doctor if you are having problems. It's also a good idea to know your test results and keep a list of the medicines you take.
Complete the new medication information form (PDF)(What is a PDF document?) to help you understand this medication.
Drugs for treatment of chronic heart failure (2009). Treatment Guidelines From The Medical Letter, 7(83): 53-56.
Yancy CW, et al. (2013). 2013 ACCF/AHA Guideline for the management of heart failure: A report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. Journal of the American College of Cardiology, 62(16): e147-e239.
Primary Medical ReviewerRakesh K. Pai, MD, FACC - Cardiology, Electrophysiology
Specialist Medical ReviewerMargaret Hetherington, PHM, BsC - Pharmacy
Current as ofMarch 12, 2014