Calcium Channel Blockers

What is a calcium channel blocker?

A calcium channel blocker is a medication that can lower your blood pressure. This medicine limits how much calcium can go into and out of cells in your heart and blood vessels. Calcium channel blockers often treat heart and blood vessel issues.

These conditions include:

• High blood pressure
• Arrhythmias (irregular heart rhythms)
• Chest pain (angina)
• Coronary artery spasm

Healthcare providers also prescribe calcium channel blockers for “off-label” uses. This means a drug can treat a condition, even if the drug doesn’t have official approval for it.

Off-label uses of calcium-channel blockers include:

• Raynaud’s phenomenon
• Migraine prevention
• Anal fissures
• High-altitude pulmonary edema
• Enlarged heart
• Pulmonary hypertension

Bleeding between your brain and skull

Healthcare providers often prescribe calcium channel blocker drugs, mainly for high blood pressure. Millions of adults in the United States receive a prescription for a calcium channel blocker each year.

Types of calcium channel blockers

Calcium channel blockers come in two main types, dihydropyridines (DHP) and non-dihydropyridines (non-DHP).

Dihydropyridines (dy-hy-dro-py-rid-eens) target blood vessels and make them relax. This is why they work well for treating high blood pressure.

Dihydropyridines include:

• Amlodipine
• Clevidipine
• Felodipine
• Isradipine
• Nicardipine
• Nifedipine
• Nimodipine
• Nisoldipine

Non-dihydropyridines target heart muscles as well as blood vessels. They can treat heart rhythm problems. Non-dihydropyridines include diltiazem (a benzothiazepine) and verapamil (a phenylalkylamine).

Most newer calcium channel blockers are dihydropyridines. But experts also include phenylalkylamines and benzothiazepines when listing three classes of calcium channel blockers.

How do calcium channel blockers work?

Calcium channel blockers block some of the channels calcium uses to go into and out of your cells. That slows down those cells’ use of calcium because there are fewer ways to bring it inside.

Certain types of calcium channels exist only in certain parts of your body, like your heart and blood vessels. This is why these medicines can target certain channels they affect.

How long will I need to take this medication?

In some cases, you may be able to improve your health to a point where you don’t need to take calcium channel blockers any longer. For example, you could eat certain foods and get more physical activity to lower your blood pressure.

If you do this, you need to talk to your healthcare provider. They can help plan a way to wean you off calcium channel blockers. You should never stop these medications suddenly without talking to your provider.

But if you have a condition like an arrhythmia or enlarged heart, you can expect to stay on calcium channel blockers for the long term.

In general, calcium channel blockers you take by mouth are safe for long-term use. In many cases, you can take them for as long as you need them.

What are the potential benefits and risks of this treatment?

Calcium channel blockers have several benefits, like:

• They work: Calcium channel blockers are effective in people of all ages. And they can treat many related heart and blood vessel problems.
• They can target certain conditions: Healthcare providers can prescribe a specific type of medicine that’s more likely to provide certain results.
• They can be a better option: Some medicines for high blood pressure aren’t a good choice for certain people. That can happen because of other health conditions or medications they take.
• They can work alongside other medications: Certain medicines combine calcium channel blockers with other drugs, like those for high cholesterol. It’s simpler to take one pill.

Calcium channel blocker side effects from dihydropyridines may include:

• Lightheadedness or dizziness
• Flushed feeling
• Headaches
• Arm or leg swelling

Side effects from non-dihydropyridines may include:

• Constipation
• Fatigue
• Slow heartbeat
• Decline in how well your heart can pump

Many calcium channel blockers can make your gums grow too much around your teeth. They may also cause an increase in symptoms of chronic acid reflux (GERD).

When should I call my healthcare provider?

Your healthcare provider can tell you when to call or schedule a visit while taking calcium channel blockers. In general, you should call if you have a sudden change in symptoms, namely ones related to your heart and blood vessels.

You should seek medical care right away if you have any of these symptoms:

• Shortness of breath
• Chest pain
• Irregular heart rhythms (arrhythmias)
• Heart palpitations (racing, pounding or skipping heartbeats)
• Fainting
• Repeated bouts of dizziness

You should also seek care right away if you have any symptoms related to allergic reactions. These include a moderate to severe skin rash or swelling in your face or limbs.

What should I do if I take one of these medications and miss a dose?

If you miss a dose of one of these medications, you should never try to “catch up” by taking an extra dose. This can lead to a calcium channel blocker overdose.

Even doubling your dose may be dangerous. For example, verapamil strongly affects the timing and strength of your heartbeat. Correct dosing of calcium channel blockers matters for them to be effective and safe.

Who should avoid calcium channel blockers?

In general, you may not be able to take a calcium channel blocker if you have certain types of heart problems (like heart failure) or low blood pressure. Other reasons why you may not be able to take some of these medicines include:

• Pregnancy
• Liver problems
• Certain types of irregular heart rhythms

Do calcium channel blockers interact with any other medications?

Calcium channel blockers can interact with many medications. They don’t mix with any medication that lowers your blood pressure or affects your heart rate. You may also want to avoid taking calcium channel blockers with grapefruit (either the fruit or the juice) because it can affect how your body absorbs these medications.

Your healthcare provider or pharmacist is the best source of information on medication interactions. Don’t hesitate to ask them if you have any questions about this.