Vasodilators are medications that open (dilate) blood vessels. They affect the muscles in the walls of the arteries and veins, preventing the muscles from tightening and the walls from narrowing.
As a result, blood flows more easily through the vessels. The heart doesn't have to pump as hard, reducing blood pressure.
Some drugs used to treat hypertension, such as calcium channel blockers also dilate blood vessels. But the vasodilators that work directly on the vessel walls are hydralazine and minoxidil.
Doctors prescribe vasodilators to prevent, treat or improve symptoms in a variety of conditions, such as:
- High blood pressure
- High blood pressure during pregnancy or childbirth (preeclampsia or eclampsia)
- Heart failure
- High blood pressure that affects the arteries in the lungs (pulmonary hypertension)
Direct vasodilators are strong medications that generally are used only when other medications haven't controlled blood pressure adequately.
These medications have a number of side effects, some of which require taking other medications to treat.
Side effects include:
- Rapid heartbeat (tachycardia)
- Heart palpitations
- Fluid retention (edema)
- Excessive hair growth
- Joint pain
- Chest pain
Sept. 25, 2021
- Types of blood pressure medications. American Heart Association. https://www.heart.org/en/health-topics/high-blood-pressure/changes-you-can-make-to-manage-high-blood-pressure/types-of-blood-pressure-medications. Accessed Sept. 21, 2021.
- Brook RD, et al. Treatment of resistant hypertension. https://www.uptodate.com/contents/search. Accessed Sept. 21, 2021.
- Whelton PK, et al. 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults: A report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Hypertension. 2018; doi:10.1161/HYP.0000000000000065.
- Hydralazine. IBM Micromedex. https://www.micromedexsolutions.com. Accessed Sept. 21, 2021.
- Minoxidil. IBM Micromedex. https://www.micromedexsolutions.com. Accessed Sept. 21, 2021.