Vasodilators: Uses, common brands, and safety info

Vasodilators are medications across several classes of drugs that are primarily used to treat health conditions arising from cardiovascular problems. Types of drugs that are considered vasodilators include medications that are categorized as angiotensin-converting enzyme inhibitors (ACE inhibitors), angiotensin receptor blockers (ARBs), calcium channel blockers (CCBs), and nitrates. While these medications have different mechanisms of action, the result is dilating or opening up blood vessels. 

Continue reading to learn more about vasodilators, their uses, and their side effects.

Other vasodilators

• Epaned (enalapril)

• Prinivil (lisinopril)

• Edarbi (azilsartan)

• Teveten (eprosartan)

• Cleviprex (clevidipine)

• Dynacirc (isradipine)

• Cardene (nicardipine)

• Nimotop (nimodipine)

• Monoket, Ismo (isosorbide mononitrate)

• Carlopam (fenoldopam)

• Nipride (nitroprusside)

What are vasodilators?

Vasodilators are medications that relax the smooth muscle of blood vessels. This results in vasodilation, or a widening of the blood vessels. When a blood vessel dilates or opens up, blood is able to flow more freely through the vessel. This helps promote an antihypertensive, or blood-pressure-lowering effect. Vasodilation not only helps lower blood pressure but also makes it easier for the heart to pump blood through the body. 

Arteries and veins are affected by vasodilators. Vasodilators can help increase arterial blood flow and oxygen supply to the heart. The dilation of veins reduces the amount of venous blood flow to the heart and eases the workload on the heart. 

How do vasodilators work?

Vasodilators work by relaxing the smooth muscle in blood vessels. This causes the walls of the blood vessel to widen, and more blood flows through the vessel. Some vasodilators work primarily on arteries while others affect veins, and still, others have a mixed effect on both arteries and veins. Vasodilators reduce blood pressure and decrease the workload of the heart, allowing the heart to pump more efficiently. 

What are vasodilators used for?

Vasodilators are primarily used to treat cardiovascular conditions. Conditions that a vasodilator may be prescribed for include:

• High blood pressure

• Congestive heart failure

• Chest pain (angina)

• Prevention of stroke

• Prevention of heart attack

• Preeclampsia (high blood pressure during pregnancy)

• Pulmonary hypertension (high blood pressure in the lungs)

• Diabetic nephropathy

• Raynaud’s syndrome

• Cardiomyopathy (heart muscle disease)

• Subarachnoid hemorrhage (bleeding in the brain)

Types of vasodilators 

There are several classes of medication that are considered vasodilators. They include the following categories:

ACE inhibitors

Angiotensin converting enzyme (ACE) inhibitors block the angiotensin-converting enzyme, which converts angiotensin I to angiotensin II. Angiotensin II is a potent hormone that causes the smooth muscles around the blood vessels to contract, resulting in the narrowing of blood vessels and a rise in blood pressure. When ACE inhibitors block angiotensin II production, blood vessels can expand to allow blood to flow more freely. 

Treatment with ACE inhibitors can promote decreased blood pressure, reduced damage to blood vessel walls, and improved blood flow to the heart and kidneys. Lowering blood pressure can also improve heart function in heart failure and slow the progression of renal, or kidney, disease caused by diabetes or hypertension.

Examples of ACE inhibitors include:

• Zestril (lisinopril)

• Lotensin (benazepril)

• Vasotec (enalapril)

ARBs

Angiotensin II receptor blockers (ARBs) prevent angiotensin II from binding to receptors around the blood vessel that cause contraction. This action is similar to the effect of an ACE inhibitor. However, ACE inhibitors prevent the formation of angiotensin II while ARBs block the activity of angiotensin II. The result in both cases is the dilation of blood vessels and increased blood flow. Blood pressure is reduced, making it easier for the heart to pump.

Examples of ARBs include:

• Benicar (olmesartan)

• Cozaar (losartan)

• Atacand (candesartan)

CCBs

The smooth muscle of arteries requires calcium for contraction. Calcium channel blockers (CCBs) block calcium from entering the smooth muscle cells of the heart and blood vessels This relaxes arteries and leads to the dilation of the arteries. Some CCBs also slow heart rate and may help control fast, irregular heart rates, or arrhythmias. 

Examples of CCBs include:

• Cardizem (diltiazem)

• Calan (verapamil)

• Norvasc (amlodipine)

Nitrates

Nitrates have a direct effect on the smooth muscles of blood vessels, causing dilation. Nitrates are primarily used to treat angina, heart attacks, and congestive heart failure. Dilation of the coronary arteries supplying the heart muscle improves oxygen flow to the heart. 

Examples of nitrates include:

• Nitrostat

• Isordil

Who can take vasodilators?

Adults

Vasodilators are commonly prescribed to adults to treat hypertension, heart failure, and other heart problems. The choice of medication will depend on the condition being treated along with any other accompanying problems. According to guidelines from the American College of Cardiology and the American Heart Association, first-line medications for hypertension in non-black adults less than 60 years of age include an ACE inhibitor or ARB. In non-black adults older than 60, a CCB is the first-line treatment, followed by an ACE or ARB. Among African Americans, there tends to be an inadequate response to ACE inhibitors; therefore, diuretics or CCBs are often the recommended first choice. 

In individuals with conditions other than hypertension, the following first-line treatment recommendations might be made:

• Diabetes: ACE inhibitor or ARB. If African American, then CCB

• Chronic kidney disease: ACE inhibitor or ARB (ACE inhibitor for African Americans)

• Coronary artery disease: ACE inhibitor or ARB

• Stroke history: ACE inhibitor or ARB

• Heart failure: ACE inhibitor or ARB

In patients with heart failure or resistant hypertension, more than one medication is often needed. Either an ACE inhibitor or an ARB can be taken, but they should not be taken together. Either can be taken with other vasodilators. 

Because some CCBs control heart rate in addition to vasodilation, individuals with a rapid heart rate, heart rate irregularities, or arrhythmias can benefit from a CCB. 

Nitrates are primarily used to control angina. They can not be taken with Viagra (sildenafil) and other medications for erectile dysfunction. This can result in serious side effects, such as hypotension (low blood pressure), dizziness, lightheadedness, or fainting.

Children

Vasodilators can be given to children. Children diagnosed with hypertension, congenital heart disease, cardiomyopathy, or arrhythmias may need a vasodilator. The age at which drugs can be administered varies. 

ACE inhibitors are a first-line medication used to treat hypertension in children. They are a preferred medication in children who also have kidney disease with proteinuria and diabetes. Children of African ancestry may need a higher starting dose. Most ACE inhibitors are safe for children aged 6 years of age and up and are dosed according to weight; however, a few formulas are safe for younger children. Capoten (captopril) may be given to infants, and Vasotec may be given to children one month of age and older. 

ARBs approved for use in children include Atacand (candesartan), Avapro (irbesartan), Cozaar (losartan), Benicar (olmesartan), and Diovan (valsartan). All these medications can be used in children aged six and older. Atacand is approved for ages 1 year and older. The dosing of ARBs is based on the child’s weight. 

CCBs for administration in children include Norvasc (amlodipine), Dynacirc (isradipine), Procardia (nifedipine), and Verelan (verapamil). These medications may be a good choice in children who have diabetes because they may also improve insulin sensitivity. Norvasc is the drug that has been studied most widely in hypertensive children. Pediatric doses of these medications are based on the age and weight of the child. Medicines that are extended-release formulas must be swallowed whole, but others may be reconstituted into a liquid. 

Nitrates are considered third-line additions for hypertension in children. Approved medications include hydralazine and minoxidil. Dosing is based on the weight of the child. 

Seniors

Older adults may safely take vasodilators. They are often used for the treatment of chronic conditions commonly found in older adults. Seniors may require a lower dose than younger adults. Starting doses may be lower and gradually titrated upward to achieve the desired effect. 

Are vasodilators safe?

In general, vasodilators are safe when taken as prescribed. However, there are a few groups of people that should avoid these types of meditations.

People with severe kidney failure should not take vasodilator ACE inhibitors. Kidney function would need to be closely monitored if an ACE inhibitor were used. 

If you’ve ever had an allergic reaction that resulted in swelling of the lips or tongue, you should not take a vasodilator ACE inhibitor. This is true even if the swelling was the result of a bee sting. 

ACE inhibitors and ARBs may increase potassium levels. For this reason, if you are taking an ARB medication, avoid the use of salt substitutes. Salt substitutes also contain potassium, and taking the two together may result in an elevated potassium level. 

Medications in the vasodilator class may come in long-acting or extended-release forms. These medications must be swallowed whole. Never crush a long-acting tablet or open a long-acting capsule. 

Vasodilator recalls

In late late 2019 the Food and Drug Administration (FDA) discovered impurities in some ARB medications. The substance identified was N-nitrosodimethylamine (NDMA). NDMA is an environmental contaminant and a possible carcinogen. Not all ARBs were affected, but many batches of ARB medications were recalled.

While of concern to many patients, the probability of risk is minimal. Experts estimate that even if taking a product containing the highest dose of NDMA daily for four years, one in 8000 people might develop cancer. 

The following list details medications that have been recalled.

• Telmisartan recall, 3/24/2021

• Valsartan recall, 3/20/2020

• Valsartan recall, 3/19/2020

• Losartan recall, 9/19/2019

• Losartan recall, 9/29/2019

• Losartan recall, 7/15/2019

• Losartan recall, 6/26/2019

• Losartan recall, 6/11/2019

• Losartan recall, 5/3/2019

• Irbesartan recall, 5/3/2019

• Losartan recall, 4/26/2019

• Losartan recall, 4/18/2019

• Losartan recall, 3/19/2019

• Losartan recall, 3/15/2019

• Losartan recall, 3/28/2019

• Valsartan recall, 3/7/2019

• Losartan recall, 3/1/2019

• Valsartan recall, 3/1/2019

• Losartan recall, 2/28/2019

• Losartan recall, 1/3/2019

• Losartan recall, 1/22/2019

• Irbesartan recall, 1/18/2019

• Valsartan recall, 12/31/2018

• Losartan recall, 12/20/2018

• Valsartan recall, 12/4/2018

• Valsartan recall, 7/17/2018

• Valsartan recall, 7/18/2018

• Valsartan recall, 7/16/2018

Vasodilator restrictions

Do not take vasodilators if you have had an allergic reaction to other medications in the same class. 

Low blood pressure, dizziness, or episodes of passing out can occur with the first several doses of vasodilators. This tends to occur more in individuals who are volume-depleted when starting a medication. Fluid imbalances should be corrected before starting a vasodilator.

Individuals taking Viagra (sildenafil) and other medications for erectile dysfunction should avoid the use of nitrates. Otherwise, there is an increased risk of low blood pressure. 

Inform your healthcare provider of all other medications and supplements you may be taking. Certain vasodilators interact with additional medications and supplements.

Can you take vasodilators while pregnant or breastfeeding?

The vasodilators in the ACE inhibitor and ARB class carry a black box warning against use during pregnancy. ACE inhibitors and ARBs can cause injury and death to a developing fetus. Additionally, ACE inhibitors may cross into breast milk, and they should be avoided while breastfeeding. It is unknown if ARBs cross into breast milk; therefore, it is not generally recommended to take an ARB while breastfeeding. 

CCBs are generally regarded as safe for women who are pregnant or breastfeeding. Typically, other medications are tried first when needed to control high blood pressure during pregnancy. However, for some women who become pregnant while taking a CCB, it is best to continue the current medication with close monitoring. 

Some vasodilator nitrates are permitted during pregnancy, while others are contraindicated. It is not known if many nitrates cross into breast milk. Risks versus benefits must be considered in breastfeeding mothers. 

Are vasodilators controlled substances?

No, vasodilators are not controlled substances. 

Common vasodilators side effects

The most common side effects of vasodilators include:

• Dizziness

• Headache

• Flushing

• Chest pain

• Heart palpitations

• Rapid heartbeat

• Edema, or fluid retention

• Nausea or vomiting

• Excessive hair growth

• Nasal congestion

• Fainting

More severe but rare side effects of vasodilators include:

• Kidney failure

• Allergic reactions

• Liver dysfunction

• Angioedema

Although rare, vasodilators can have serious side effects. One adverse event possible from an ACE inhibitor is angioedema, a rare condition that causes swelling of the face and other body parts. 

ACE inhibitors and ARBs can raise blood potassium levels and cause hyperkalemia (when potassium levels get too high), so monitoring potassium intake while taking an ACE inhibitor or ARB is often necessary. Taking potassium supplements or using salt substitutes containing potassium while on an ACE inhibitor or ARB may cause hyperkalemia, leading to other health problems and potentially life-threatening conditions. Signs of having too much potassium in the body include confusion, irregular heartbeat, and tingling or numbness in the hands or face.

In people with a history of irregular heart rates, slow heart rates, or certain arrhythmias, CCBs may make symptoms worse. Individuals with hypertrophic obstructive cardiomyopathy will also want to avoid CCBs. 

This list of side effects is not comprehensive. Speaking with a healthcare professional is the best way to get a complete list of side effects and determine whether taking vasodilators is suitable.

Seek medical advice from a healthcare provider before taking a vasodilator. You should also tell your doctor about any of the following before taking a vasodilator:

• Any drug allergies

• If you’ve ever experienced angioedema

• If you have kidney problems

• If you are taking a drug that has aliskiren in it

• If you have diabetes or kidney problems

• If you have taken a drug that has sacubitril in it in the last 36 hours

• If you are breastfeeding

• If you have severe headaches

• If you are taking medication for erectile dysfunction

• If you have liver problems

• If you have experienced heartbeat irregularities or arrhythmias

• If you are pregnant or intend to become pregnant

How much do vasodilators cost?

Vasodilators are generally affordable medications that are available in brand-name and generic formulas. Almost all Medicare and insurance plans will cover vasodilators. Costs will vary depending on your insurance plan. Without insurance, the price can vary widely depending on the medication and quantity of tablets prescribed. However, using a prescription discount card from SingleCare may help reduce the cost of vasodilators.