Amlodipine: everything you need to know

Amlodipine (brand name Norvasc) is one option to treat high blood pressure. It belongs to the calcium channel blocker class of medications.

Calcium channel blockers (CCB) stops calcium from entering the "slow channels" of the muscles in blood vessels and heart tissue. Calcium causes muscles to squeeze or contract; calcium channel blockers allow the muscles to relax, thereby dilating or opening the blood vessels, lowering the blood pressure, and easing the workload on the heart (UpToDate, n.d.). Dilated vessels allow more blood to travel to the heart and other parts of the body. Calcium channel blockers are an effective way to treat high blood pressure. Other examples of calcium channel blockers include diltiazem and verapamil.

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Amlodipine is FDA-approved for the following indications (FDA, 2011):

• High blood pressure (hypertension)

• Coronary artery disease (CAD): People who have coronary artery disease confirmed by additional testing to visualize the vessels (angiography) may have a decreased risk of needing hospitalization or heart procedures with amlodipine.

• Vasospastic (Prinzmetal's) angina 

• Chronic stable chest pain (angina)

High blood pressure

According to the American Heart Association (AHA), almost half of all Americans have high blood pressure (hypertension)—unfortunately, many of them don't even realize that they have it (AHA, 2017). For most people, their high blood pressure does not cause any symptoms. If left untreated, over time, hypertension can lead to heart attacks, strokes, kidney disease, and other problems. Treatment often involves lifestyle changes, like a healthy diet, regular physical activity, and smoking cessation. For some, this is not enough, and they need to start blood pressure medications (also called antihypertensive drugs). Amlodipine helps to lower blood pressure either alone or in combination with other antihypertensive medicines.

Coronary artery disease

Coronary artery disease (or coronary heart disease) is a heart condition caused by a build-up of fatty deposits (plaque) along the walls of the coronary arteries (the vessels that nourish the heart). As the plaque gets thicker, the arteries’ inner channel (lumen) gets narrower, and less oxygen-rich blood can get to the heart—this is called atherosclerosis. Atherosclerosis may worsen over time, eventually blocking off the vessel entirely. This starves the area of the heart fed by that vessel, and heart cells start to die—this is a heart attack (myocardial infarction). Coronary heart disease is the leading cause of death in the United States in both men and women (NHLB, n.d.).

Some people with coronary artery disease may need additional testing (angiography) to confirm which vessels are narrowed and to what degree. In these cases of angiography-confirmed coronary artery disease, taking amlodipine may decrease the risk of needing hospitalization for chest pain or heart procedures to reopen blood vessels (recatheterization) (DailyMed, 2008).

Vasospastic (Prinzmetal's) angina

Unlike the typical chest pain of heart disease, vasospastic angina happens while resting, rather than during exertion. It is due to spasms in the coronary arteries. According to the American Heart Association, vasospastic angina is rare and usually occurs in people younger than those who present with chest pain from heart disease (AHA, 2015). Factors that may trigger the blood vessel spasms include cold weather, stress, smoking, medications that constrict (narrow) blood vessels, and cocaine use. Amlodipine relaxes the blood vessels, thereby relieving the spasm and improving chest pain (DailyMed, 2008).

Chronic stable chest pain (angina)

Chest pain, or angina, is a common sign of coronary heart disease. As coronary heart disease progresses, atherosclerosis gets worse and less oxygen-rich blood can get to the heart. This lack of oxygen can trigger angina or chest pain. This pain is sometimes described as a pressure or heaviness on your chest. Other people report squeezing or tightness.

Chronic stable angina is chest pain that occurs primarily when you make your heart work harder, usually through physical activity. Classically, people experience stable angina when climbing stairs or walking for several minutes. The pain usually lasts about five minutes and resolves when you rest or take angina medications. Stable angina is relatively predictable and usually feels the same each time. Amlodipine can improve the symptoms of long-term chest pain.

Off-label

Amlodipine is also prescribed for Reynaud's phenomenon; this is an "off-label" use. "Off label" means that it was not specifically FDA-approved to treat this condition (UpToDate, n.d.). Reynaud's phenomenon occurs when the blood vessels to your fingers and/or toes spasm in response to cold or stress. 

Studies looking at the safety and effectiveness of over 11,000 people have shown that amlodipine is an effective and well-tolerated medication (DailyMed, 2008). However, like most drugs, you may experience side effects.

Common side effects include (DailyMed, 2008): 

• Headache

• Edema (swelling) 

• Tiredness 

• Nausea 

• Sleepiness

• Stomach pain

• Flushing

Serious side effects include (MedlinePlus, 2019): 

• More severe or more frequent chest pain, especially in people with severe heart disease

• Palpitations (fast, pounding, or irregular heartbeat)

• Fainting

This list does not include all possible side effects and others may occur. Get medical advice from your pharmacist or healthcare provider for more information.

Before starting amlodipine, be sure to seek medical advice regarding your other medications to avoid any potential drug interactions. Some medicines can increase the risk of side effects or make amlodipine less effective when used in combination. Alternatively, amlodipine may change the effectiveness of other medications you are taking. Drug interactions include (FDA, 2011):

• Diltiazem: Taking diltiazem with amlodipine can increase the amount of amlodipine in your body by 60%. This increase can lead to low blood pressure, swelling of your feet/legs, trouble breathing, and other symptoms.

• Drugs that block the CYP3A4 system: The CYP3A4 system in the liver is responsible for breaking down amlodipine. Any drug that interferes with this process can lead to higher than anticipated levels of amlodipine in your body, increasing the risk of low blood pressure and other side effects. Examples of drugs that block the CYP3A4 in the liver include ketoconazole, itraconazole, and ritonavir.

In general, most healthcare providers do not recommend that people with heart failure use calcium channel blockers. However, amlodipine is one of the few calcium channel blockers that can be used in heart failure—studies have not shown that amlodipine worsens heart failure symptoms (DailyMed, 2008).

In clinical trials, amlodipine has been used safely with other heart and blood pressure medications like beta blockers, angiotensin converting enzyme (ACE) inhibitors, nitroglycerin, atorvastatin, etc. (DailyMed, 2008). 

This list does not include all possible drug interactions with amlodipine and others may exist. Check with your pharmacist or healthcare provider for more information.

Anyone with an allergic reaction to amlodipine should not use this medication. Also, certain groups of people should avoid using this drug or use amlodipine with caution because of the risk of side effects. These groups include (UpToDate, n.d.):

• People with aortic stenosis: Aortic stenosis is a narrowing of the valve where the aorta (the largest artery) exits the heart. Using amlodipine in this condition increases the risk of low blood flow to the coronary arteries (arteries that feed the heart).

• People with obstructive hypertrophic cardiomyopathy (HCM): Some people have a genetic predisposition for thickening of the walls of the heart. Thicker walls decrease the amount of blood that flows in and out of the heart with each beat. Taking amlodipine with this condition can worsen the symptoms.

• People with liver disease: Since the liver breaks down amlodipine, people with liver disease may require a dose adjustment.

• Older people: People older than 65 years of age may get rid of amlodipine slower than younger people; this can lead to a buildup of the drug and potentially increase the risk of side effects. For this reason, older people may want to start at the lowest dose and increase as necessary.

• Pregnant women or women who are breastfeeding: According to the FDA, amlodipine is pregnancy category C; this means that there is not enough information to determine the risk to the pregnancy (FDA, 2011). Amlodipine has been measured in small quantities in breastmilk, but no adverse effects have been reported. Women and their healthcare providers should weigh the risks and benefits of the medication.

Most people use amlodipine besylate tablets, although it is available as an oral suspension. Amlodipine is available under the brand name Norvasc or as generic tablets; the pills come in 2.5 mg, 5 mg, and 10 mg strengths. You can take amlodipine either with food or without. If you miss a dose, take it as soon as you remember; however, if it is almost time for the next tablet, skip the missed one and get back on schedule. Never take double the pills to make up for a missed dose. Most insurance plans cover it, and the cost for a 30-day supply of amlodipine ranges from about $6.50–$9 (GoodRx.com)

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How we reviewed this article

Every article on Health Guide goes through rigorous fact-checking by our team of medical reviewers. Our reviewers are trained medical professionals who ensure each article contains the most up-to-date information, and that medical details have been correctly interpreted by the writer.

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Current version

September 14, 2020

Written by

Chimene Richa, MD

Fact checked by

Mike Bohl, MD, MPH, ALM

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About the medical reviewer

Mike Bohl, MD, MPH, ALM

Dr. Mike is a licensed physician and a former Director, Medical Content & Education at Ro.