Norvasc: common and serious side effects

Amlodipine, or amlodipine besylate, is also known by its brand name Norvasc. It is an FDA-approved medication used to treat hypertension (high blood pressure), either by itself or along with other blood pressure medicines. It belongs to the calcium channel blocker (CCB) class of medications. It works by opening up (dilating) the blood vessels, lowering blood pressure, and easing the strain on the heart (UpToDate, n.d.). 

Amlodipine can also help with coronary artery disease (CAD), a buildup of plaque in the blood vessels that supply the heart muscle with oxygen, and chest pain (angina). By dilating the vessels, amlodipine allows more blood to travel to the heart and other parts of the body. Other examples of calcium channel blockers include diltiazem and verapamil.

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According to clinical trials involving more than 11,000 people worldwide, amlodipine is a safe and well-tolerated drug. Most people experienced mild to moderate side effects—only 1.5% of people experienced side effects bothersome enough to cause them to stop the medication. 

Common side effects of Norvasc include (DailyMed, 2008):

• Headaches

• Edema (swelling)

• Flushing

• Palpitations (feeling like the heart is racing or fluttering)

• Unusual tiredness 

• Nausea or stomach pain

• Somnolence (sleepiness)

• Dizziness or lightheadedness

Headaches are among the most common side effects that people taking amlodipine experience. However, several of the other adverse effects are dose-dependent; this means that you are more likely to experience certain side effects at higher doses (DailyMed, 2008).

As an example, let’s look at edema (or swelling), another of the more common side effects of amlodipine. The rate of edema in people taking the standard starting dose of 5 mg per day was 3%, but it increased to over 10% when the dose was increased to 10 mg per day. Scientists theorize that the edema from amlodipine happens because fluid from inside the body’s vessels moves into the soft tissues due to fluid pressure changes (DailyMed, 2008). 

One study found that as many as 46.5% of their participants had swelling in their ankles (Galappatthy, 2016). Most people experience swelling within 2–3 weeks of starting the drug (UpToDate, n.d.).

Flushing and palpitations (rapid or fluttering heart rate) also occurred more often when the dose was increased from 5 mg to 10 mg. This chart summarizes how the likelihood of certain adverse effects changes with amlodipine strength (DailyMed, 2008). 

Another interesting trend that researchers noted was that some side effects were more common in women than in men. These included edema, flushing, palpitations, and sleepiness (also called somnolence), which occurred more often in women than men, regardless of the dose (DailyMed, 2008). Women also have a more significant drop in blood pressure with amlodipine, suggesting that women may have more of the drug circulating in their system than men (also called relative dose) (Kloner, 1996). 

This chart summarizes the side effects that seem to affect women more than men. 

Along with the common side effects, there are also some serious side effects associated with amlodipine that you should know. Amlodipine can treat stable, long-standing chest pain in people with coronary artery disease (also called CAD or heart disease) (DailyMed, 2008). 

However, people with severe CAD are at higher risk of developing more frequent or worsening chest pain (angina) or even heart attacks (myocardial infarctions) with amlodipine—especially when starting the drug or increasing the dose of amlodipine. Researchers don’t know why this happens, but it is important to know about this potentially serious side effect if you are taking amlodipine (DailyMed, 2008).

Most medications that treat high blood pressure carry with them the risk of causing low blood pressure—a medical condition called hypotension. Amlodipine is no exception. If your blood pressure does go too low, you may experience fainting and dizziness. 

Other side effects may occur. In addition, there may be drug interactions with other medicines you are taking, whether prescription drugs or over-the-counter remedies. Seek medical advice from your healthcare professional for more drug information.

Roughly half of all Americans have high blood pressure (hypertension). The American Heart Association (AHA) calls it the “silent killer” because most people do not have any symptoms and don’t even realize that they have hypertension—if left untreated, it can lead to heart attacks, strokes, and kidney disease, among other problems (AHA, 2017). 

Treating high blood pressure is usually a two-pronged approach. Many people need a combination of lifestyle changes (like a healthy diet, exercise, and smoking cessation) along with medications to lower blood pressure, also called antihypertensive drugs. In some cases, healthcare providers may prescribe amlodipine in combination with other blood pressure-lowering medicines. 

Coronary artery disease is a condition in which plaque builds up along the walls of the coronary arteries, the vessels that supply the heart with blood and oxygen. The buildup of plaque on the walls of the arteries (atherosclerosis) prevents adequate blood flow to the heart muscle. That can worsen over time, eventually blocking off the vessel entirely and causing a heart attack. If you have CAD, your healthcare provider may inject a special dye into your bloodstream and take pictures of your coronary arteries to look for narrowing or blockage—this procedure is called angiography. For people who have CAD on angiography, taking amlodipine may decrease the risk of hospitalization for chest pain or heart procedures to reopen blood vessels (DailyMed, 2008). 

The narrowing of the coronary arteries from atherosclerosis can cause episodes of chest pain, also called angina. Angina is a sign that your heart muscle is not getting the oxygen-rich blood that it needs. Stable angina is chest pain that occurs when you make your heart work harder, usually through physical activity (like walking or climbing stairs)—this is a common sign of coronary artery disease. 

However, atherosclerosis is not the only thing that can cause your coronary arteries to narrow. Some people develop spasms of their arteries—when the arteries spasm, they temporarily narrow and decrease blood flow to the heart and cause chest pain. Unlike CAD, angina from artery spasms happens while resting, rather than when you are active. This is called Prinzmetal angina. Amlodipine can help with chest pain because it opens up the coronary arteries and relieves the spams, thereby improving the chest pain. 

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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

December 02, 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.