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If you’ve recently been prescribed amlodipine (brand name Norvasc)—a drug commonly used to treat high blood pressure—you probably have some questions. We’re here to separate fact from fiction and answer some of the most common questions about amlodipine.
The truth about amlodipine: 9 FAQs and misconceptions
If you’re taking amlodipine, you may have heard that it’s unsafe, causes unpleasant side effects like weight gain, or even that it’s been recalled for containing carcinogens. However, many of the rumors circulating about amlodipine are based on misleading information. Here are answers to your most pressing questions.
1. Is amlodipine a beta blocker?
No, amlodipine is not a beta blocker—it’s a calcium channel blocker. Both drugs have a similar effect on blood pressure but different mechanisms of action.
“Beta blockers affect heart rate and how fast the heart beats,” says Jennifer Wong, MD, cardiologist and medical director of Non-Invasive Cardiology at MemorialCare Heart and Vascular Institute at Orange Coast Medical Center in California. “Calcium channel blockers have vasodilating effects that help the smooth muscles of the arteries dilate and lower your blood pressure.”
2. Is amlodipine a blood thinner?
No. Blood thinners are anticoagulants that make your blood less prone to clotting. Some blood thinners you may have heard of include Coumadin (warfarin), Eliquis (apixaban), and Xarelto (rivaroxaban). Amlodipine doesn’t have any effect on the thickness of your blood or how it clots.
3. How does amlodipine work?
Calcium channel blockers like amlodipine affect the movement of calcium into the heart and blood vessels, which relaxes the blood vessels. This allows blood to flow more freely, which not only relieves angina by allowing more blood and oxygen to circulate through your body and reach your heart, but also helps lower blood pressure.
4. Do I have to take amlodipine at bedtime?
You don’t have to take amlodipine at bedtime, explains Dr. Wong, as long as you take it consistently at the same time each day. But there are benefits to taking some kind of blood pressure medication, whether it’s amlodipine or something else, before you go to sleep.
“Your blood pressure varies throughout the day, [and is usually] highest in the morning and drops at night,” Dr. Wong says. “But sometimes as we age, that nighttime drop doesn’t happen, increasing the risk of cardiovascular problems.” Taking amlodipine or another prescribed blood pressure medication can decrease those spikes, says Dr. Wong, and improve your overall health outcomes. Talk with your healthcare provider about the best time to take amlodipine. Amlodipine must be taken every day, so you can also discuss ways to remember to take your medicine every day, such as setting reminders on your phone or using a pill organizer.
5. How long does amlodipine stay in your system?
According to ambulatory care pharmacist MaRanda Herring, Pharm.D., amlodipine has a half-life of about 30 to 50 hours, which means it takes that amount of time for half of the drug to be eliminated from the body.
“[However], it takes about five times as long for the drug to be completely out of your system,” she warns, “[which] means some amlodipine could remain in your system for up to 11 days.”
6. Does amlodipine lower heart rate?
No, it doesn’t impact heart rate. Beta blockers work this way, but Dr. Herring says calcium channel blockers work predominantly on the peripheral arteries, dilating these blood vessels and reducing blood pressure.
7. Can I take amlodipine every other day?
Despite the long half-life of amlodipine, says Dr. Herring, its blood pressure-lowering effects start to wane after 24 hours. If you’re relying on the drug to keep your blood pressure low or your angina at bay, taking amlodipine every other day won’t be often enough, she warns: “While some medications may be taken every other day, the American Heart Association recommends against this practice with blood pressure medications like amlodipine.” Take amlodipine exactly as prescribed by your healthcare professional to get the most benefit from the medication.
8. What are the dangers of taking amlodipine?
In general, amlodipine is considered a safe and effective antihypertensive drug when taken at the correct dosage. It’s been prescribed widely for over 20 years, per a 2016 research article in Open Heart. That means we have a strong body of evidence for its use in treating hypertension and angina. Controlling blood pressure helps to reduce your risk of medical conditions including heart attack, heart disease, and stroke.
That said, amlodipine can be dangerous when taken in excessive amounts. It’s a common cause of drug overdose in cardiovascular medicine and its toxicity can be fatal, but it’s important to note that several reported cases of amlodipine overdose involved extremely high amounts of the drug (i.e., 50 or more tablets). If you think you took too much amlodipine, call Poison Control at 1-800-222-1222 or get emergency medical help. Symptoms of an amlodipine overdose may include fast heartbeat, fainting, and/or redness and warmth in the arms and legs.
In typical dosages, amlodipine can cause arterial dilation, says Dr. Wong, which can lead to swelling in the legs, excess amounts of blood pooling or collecting in the veins, dizziness, headaches, and flushing.
Though many people believe amlodipine can cause weight gain, that hasn’t been widely seen in studies or trials; it may happen in less than 1% of people taking it. The edema and swelling that amlodipine can cause may also make it seem as though the drug leads to weight gain.
Talk to your healthcare provider if you’re considering using amlodipine during pregnancy or while breastfeeding.
9. Has amlodipine been recalled?
No, amlodipine itself hasn’t been recalled. In recent years, some combination drugs for blood pressure containing amlodipine (like valsartan) were recalled, but the issue was never with the amlodipine—it was one or more of the other drugs contained in the formulation that was flagged as a possible carcinogen by the FDA.
Amlodipine contraindications
Generally, amlodipine isn’t known to cause long-term complications. It doesn’t have many serious drug contraindications, says Dr. Herring, and can often be taken with other drugs—especially other blood pressure medications, if needed.
In general, the biggest precautions you’ll need to take are regarding amlodipine’s side effects. You should be careful when standing or changing positions, for example, if you’re prone to dizziness while taking this drug. In some cases, oral problems like bleeding gums can occur; you may also notice a temporary increase in headaches until you adjust to the medication.
Although amlodipine is a generally safe drug, there are a few common interactions to keep in mind.
Drug interactions
Amlodipine can increase the amount of certain drugs in the body to potentially toxic amounts, says Dr. Herring, noting that conservative dosing and close monitoring is required if you need to take it with simvastatin, a cholesterol-lowering statin, or cyclosporine, a transplant drug.
Some other drugs can also affect the absorption of amlodipine, she says: “Medications that inhibit the CYP3A4 enzyme, like ketoconazole, itraconazole, and ritonavir, may slow the breakdown of amlodipine in the body and lead to low blood pressure and other complications.”
Diltiazem is another calcium channel blocker that affects amlodipine absorption. Amlodipine should not be taken in combination with diltiazem or any other calcium channel blockers.
Always tell your prescribing providers about any and all drugs—including prescription and over-the-counter meds and vitamins or supplements—you’re taking so they can advise you on interactions.
Food interactions
One good thing about amlodipine is that you can take it with or without food, which makes it easy to take at bedtime if that’s what you choose.
Like many other medications, you should avoid taking amlodipine with grapefruit or grapefruit juice because it can affect the drug’s absorption. Some people also believe bananas and other high-potassium foods need to be avoided or limited with amlodipine, but that’s typically more true for beta blockers, not calcium channel blockers (and, in any case, just avoid eating an excessive amount of potassium-rich foods and you should be fine!).
Finally, be mindful of how much alcohol you drink while taking amlodipine. “While there is no serious interaction between amlodipine and alcohol, alcohol can make the side effects of amlodipine, like dizziness and lightheadedness, worse,” says Dr. Herring. The combination of alcohol and amlodipine can cause severely low blood pressure. Ask your healthcare provider how much alcohol you can drink while taking amlodipine.
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Stopping amlodipine side effects
According to Dr. Wong, the most common side effects of amlodipine are leg swelling, headaches, flushing, palpitations, and dizziness. There are ways to mitigate some of these adverse effects. If you suffer from swollen legs, for example, Dr. Wong says you can wear compression socks, take diuretics, or add compatible drugs (such as nitrate vasodilators or ACE inhibitors) to counteract some of these symptoms. You can talk to your healthcare provider about these options.
In some cases to avoid serious side effects, you may also need to lower your dose of amlodipine or switch to another drug for high blood pressure, like Inderal XL (a beta blocker), losartan (an angiotensin-receptor blocker), or lisinopril or Lotensin (both ACE inhibitors). However, you shouldn’t stop amlodipine suddenly or without medical advice; while most people don’t experience classic withdrawal symptoms after a missed dose like with other drugs, it’s very likely your original condition or symptoms will return and you’ll have high blood pressure or chest pain again.
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