What to Know About Cardene (Nicardipine)

A Calcium Channel Blocker Commonly Used for Hypertension

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Cardene (nicardipine) is a calcium channel blocker that is used most often to treat hypertensionstable angina, and Prinzmetal's angina caused by spasm of the coronary arteries. Nicardipine is a member of the dihydropyradine family of calcium channel blockers, which means its major effects are concentrated on the blood vessels rather than on the heart itself. It is available in capsule form and intravenous form.

Checking blood pressure
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Because of its effectiveness in dilating blood vessels, nicardipine is most useful in treating hypertension and angina.


Nicardipine is a member of a large class of drugs known as the calcium channel blockers. Calcium channel blockers work by slowing the movement of calcium ions into certain types of cells, in particular, the smooth muscle cells that line the blood vessels, and cardiac muscle cells.

How Nicardipine Works

As a class, calcium channel blockers tend to have three different effects on the cardiovascular system. However, the strength of each of these three effects differs among the various drugs in this class. These three types of effects are:

  • Reducing calcium influx in smooth muscle cells in the walls of blood vessels, which causes the blood vessels to relax. This vascular relaxation results in the dilation of the arterial blood vessels, which has the effect of lowering blood pressure. 
  • By slowing calcium influx into cardiac muscle cells, calcium channel blockers tend to reduce the force of cardiac contraction, thus reducing cardiac work and the vigor of the heart beat.
  • Blocking the calcium channels tends to slow the function of heart's sinus node, and the rate at which the heart's electrical impulse transits the AV node. These actions on the heart's electrical system can slow the heart rate, and allow some calcium channel blockers (in particular, verapamil) to be effective in treating several kinds of cardiac arrhythmias.

Calcium channel blockers are divided into two subgroups — the dihydropyridine group, and the non-dihydropyradine group. Nicardipine belongs to the former. 

The dihydropyradine calcium blockers like nicardipine were specifically designed to emphasize their blood vessel dilating properties (so they would be useful in treating hypertension), and to minimize their direct effect on the heart muscle and the heart's electrical system.

As a result, nicardipine (and the other dihydropyradines including nifedipine, felodipine, and amlodipine), can be used effectively and safely in many people whose heart failure or bradycardias (slow heart rates) might preclude the use of the non-dihydropyradine calcium blockers (verapamil and diltiazem).

Clinical Uses

Common clinical uses for nicardipine are:

Treatment of stable angina. Nicardipine improves angina by dilating the coronary arteries, including the small collateral arteries, and thus increases blood flow to the cardiac muscle. Further, unlike beta-blockers or the non-dihydropyridine calcium channel blockers, nicardipine has only a minimal effect in reducing the strength of contraction of the heart muscle. This means it generally can be used more safely than these other drugs in people with cardiomyopathy and weakened heart muscles.

Treatment of angina due to coronary artery spasm (Prinzmetal's angina). Prinzmetal's angina, typically seen in relatively young, healthy women, is caused by spasm in the coronary arteries. Calcium channel blockers, which dilate blood vessels, are generally regarded as the drug of choice in treating this type of vasospastic angina.

Treatment of chronic hypertension. All calcium channel blockers can be used to treat hypertension, since they all tend to increase the dilation of blood vessels and lower the blood pressure. In general, the dihydropyridine calcium blockers like nicardipine are preferred over the non-dihdropyradine drugs like verapamil, because they do not reduce the contraction of the heart muscle to any great extent. 

Furthermore, nicardipine is one of the preferred drugs for treating hypertension in people with asthma. This is because it may help to reduce smooth muscle contraction in the airways, and can improve pulmonary function in people with asthma.

Treatment of hypertensive emergencies. A continuous intravenous infusion of nicardipine is useful for rapidly reducing blood pressure in people with hypertensive urgency or hypertensive emergencies. This drug can also be used intravenously after surgery, as a temporary measure in people on chronic oral hypertensive therapy who are unable to take their oral medication.

Before Taking

Before you are prescribed nicardipine, your healthcare provider will perform a full evaluation to make sure this is the right drug to treat your condition. Angina and hypertension can each be treated with several different types of medicine, in several different categories, so there will usually be several therapeutic options to consider. 

For instance, stable angina is most often treated with beta-blockers and nitroglycerin. A calcium channel blocker like nicardipine may be considered only after such initial anti-anginal drug treatment has not worked as desired, or if there is a particular reason to avoid using a beta-blocker. Nicardipine may not always be the first choice.

Precautions and Contraindications

Clinical studies using nicardipine in pregnant women are lacking. For this reason this drug should be used only during pregnancy only if the potential benefit is deemed to be compelling enough to outweigh the potential risk.

While nicardipine has less effect in reducing the strength of heart muscle contraction than other calcium channel blockers, it should still be used with caution in people with congestive heart failure.

Nicardipine should not be used in people known to be allergic to this drug. It should also be avoided in people with severe aortic stenosis.

Other Calcium Channel Blockers

The other dihydropyridines used to treat hypertension include Procardia (nifedipine), Plendil (felodipine), and Norvasc (amlodipine).

The calcium channel blocker Calan (verapamil) is used for angina and cardiac arrhythmias. Cardizem (diltiazem) affects both the heart muscle and blood vessels and tends to be better tolerated than the other calcium channel blockers.


Nicardipine is available in an immediate-release capsule (Cardene, and in generic forms), in doses of 20 and 30 milligrams (mg). It is also available in sustained-release generic capsules in doses of 20 mg, 45 mg, and 60 mg.

The manufacturer of Cardene SR capsules removed this product from the market in 2017. Subsequently, the FDA released a determination stating that Cardene SR was not removed due to any safety or effectiveness concerns, so its removal seems to have been for market-based reasons.

Nicardipine is also available in intravenous form, in doses of 0.1 mg, 0.2 mg, and 2.5 mg.

All listed dosages that follow are according to suggestions of the drug manufacturer. Check your prescription and talk to your healthcare provider to make sure you are taking the right dose for you.

Treatment of angina. Nicardipine is started at a dose of 20 mg three times per day of the immediate-release formulation and increased to as much as 40 mg three times per day if needed.

Treatment of chronic hypertension. Nicardipine is started at a dose of 20 mg three times per day of the immediate-release formulation and increased to as much as 40 mg three times per day if needed. Adults may also be treated using the sustained-release formulation in doses of 30 to 60 mg twice per day. 

Nicardipine can be used in children with hypertension, beginning with 0.5 mg/kg three times per day of the immediate-release formulation.

Treatment of hypertensive emergencies. Nicardipine intravenous infusions are typically begun at a dose of 5 mg/hour and increased no more than once every 15 minutes to a maximum of 15 mg/hour as needed to bring the blood pressure under control.

How to Take and Store

Nicardipine can be taken with or without food, but people taking this drug should avoid taking it with grapefruit juice. Nicardipine should be stored at room temperature.

Extended-release capsules should be swallowed whole. Don't split, chew, or crush them.

Side Effects


Common side effects with nicardipine include:

  • Flushing
  • Leg edema
  • Low blood pressure
  • Palpitations
  • Tachycardia (fast heart rate)
  • Headache
  • Dizziness
  • Nausea
  • Heartburn
  • Constipation


Allergic reactions to nicardipine are rare, and are usually manifested by a rash, although severe anaphylaxis may occur. Symptoms of anaphylaxis often appear suddenly, and may include hives, itching, difficulty breathing, palpitations, nausea, vomiting, headaches, confusion and dizziness. Anaphylaxis is a medical emergency, and must be treated immediately by an injection of epinephrine (as with an EpiPen), and by calling 911.

Warnings and Interactions

You should not take nicardipine if you have ever had an allergic reaction to this drug.

People with serious, active cardiovascular disease (in particular, an acute heart attack, extremely low blood pressure, heart failure, severe aortic stenosis, or severe bradycardia), should not be given nicardipine.

People with significant kidney or liver disease should not take nicardipine.

Nicardipine is not recommended during pregnancy, but intravenous nicardipine has been used to reduce the blood pressure in women with preeclampsia when the potential benefits are judged to outweigh the risks.

Nicardipine should be used cautiously in people with gastrointestinal reflux disease, as it can make this condition worse.

Drug Interactions

Numerous drugs can interact with nicardipine, so it is important for you to tell your healthcare provider about any drugs and supplements you may be taking.

Several drugs increase the speed at which nicardipine is metabolized and reduce its effectiveness. These drugs include: carbamazepine, oxcarbazepine, phenobarbital, phenytoin, and rifampin.

Other drugs can interfere with the metabolism of nicardipine, and cause blood levels to increase. These include clarithromycin, itraconizone, and ketoconazole. 

In addition, using nicardipine together with cyclosporine will result in increased blood levels of cyclosporine.

9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Richard N. Fogoros, MD
Richard N. Fogoros, MD, is a retired professor of medicine and board-certified in internal medicine, clinical cardiology, and clinical electrophysiology.