Vasodilators: Types and Side Effects

If you have a cardiovascular condition like hypertension, a healthcare professional may suggest you start taking a vasodilator.

Vaso-what? This type of prescription medication can relax smooth muscle cells in the walls of blood vessels to help blood flow through better. This is a process called vasodilation.

Vasodilators can also be used for other conditions beyond things affecting your heart. To learn more about vasodilators, keep reading. 

What Are Vasodilators?

Vasodilators, also sometimes called blood vessel dilators, help the smooth muscle cells in the walls of your blood vessels relax so blood flows through more easily. 

There are a few different types of vasodilators and each one works slightly differently to do what they’re meant to do. Some directly affect the muscles so they relax, while others contain chemicals to expand your blood vessels. 

When your blood vessels dilate, blood flows through your heart to allow it to get more oxygen, which in turn keeps it healthy and operating as normal.

The different types of vasodilators include: 

• Angiotensin-Converting Enzyme (ACE) Inhibitors: Angiotensin is a chemical that causes blood vessels to constrict. This direct vasodilator decreases angiotensin to open blood vessels.

• Nitrates: Another direct vasodilator, nitrates transform into nitrous oxide — which in turn helps open blood vessels.

• Angiotensin Receptor Blockers (ARBs): This medication prevents angiotensin from attaching to your blood vessel walls. When this attachment is prevented through this type of indirect vasodilator, it allows blood vessels to open.

• Calcium Channel Blockers (CCBs): Calcium helps arteries constrict. Calcium channel blockers prevent calcium from going to your artery walls, thereby helping them not constrict. This medication is known as a systemic vasodilator.

Minoxidil is another type of vasodilator. It can be taken orally to treat high blood pressure, but it can also be used in its topical form to treat hair loss.

But what else do these medications treat? A variety of things, really. Some of the most common conditions that vasodilators are used to treat are:  

• High blood pressure (hypertension) 

• Congestive heart failure

• Angina

• Pulmonary hypertension

Side Effects of Vasodilators

Generally, direct vasodilators have significant side effects. Because of this, they are usually only prescribed when nothing else has worked.

If a direct vasodilator is prescribed, you may need other medications to address some of the severe side effects. For example, it could cause extreme water retention (edema) and you may need a diuretic to help ease that.

Other common adverse effects connected to taking vasodilators include: 

• Fatigue

• Joint pain

• Headaches

• Dizziness

• Dry cough, especially when taking ACE inhibitors 

• Heart palpitations or increased heart rate

• Nausea and/or vomiting

Along with side effects, you need to be careful of medication interactions when taking a vasodilator. For example, ACE inhibitors can react poorly with potassium supplements and medications with lithium. Nitrates can interact poorly with sildenafil and tadalafil. It’s always important to disclose any and all medications you are currently taking before you start taking something new. 

The Most Popular Vasodilator Medications

Now that you know that there are different types of vasodilators and that they can be used to treat everything from congestive heart failure to hypertension, you may be curious which types tend to be most popular. 

As mentioned above, direct vasodilators tend to be prescribed only if nothing else works. This is because they can have intense side effects. 

ARBs are indirect inhibitors that are commonly prescribed. A popular ARB is losartan. 

CCBs are also common — one that may be suggested to you is called diltiazem. 

Breaking Down Vasodilators

Vasodilators are most commonly used to treat heart conditions such as congestive heart failure, vascular disease, high blood pressure and more.

Within vasodilators, there are different types. Direct vasodilators tend to have more severe side effects and are not used quite as often. There are also systemic vasodilators (like calcium channel blockers) and indirect vasodilators, which tend to be prescribed a bit more often.

There’s even a topical vasodilator (topical minoxidil) that can be used to treat hair loss in men.

Vasodilator medications do come with a risk of side effects — like nausea, increased heart rate and more. 

If you think you may qualify for the administration of vasodilator medication, it’s best to schedule an assessment with a healthcare provider. They will be able to assess your condition and determine the appropriate treatment plan for you.