Drug Classes

What Are Calcium Channel Blockers?

Calcium channel blockers are prescribed for high blood pressure and heart problems, but be careful when using one with diuretics, ACE inhibitors, or other drugs.

Diana Rodriguez
By
Stephanie Young Moss, PharmD
by
Updated on September 9, 2023

Calcium channel blockers are a class of drugs prescribed for high blood pressure and other heart diseases.

The medications reduce blood pressure by helping blood vessels to relax.

Calcium channel blockers reduce the speed at which calcium moves into heart muscle, blood vessels, and cells in the heart that control your heart rate, according to the American Heart Association.

The drugs increase the diameter of blood vessels, reduce the force of contraction of the heart, and slow heart rate, all of which helps keep your heart from having to work as hard.

In addition to high blood pressure (hypertension), calcium channel blockers are prescribed to treat:

These medications typically aren’t prescribed for people who have congestive heart failure or structural heart problems.

Examples of Calcium Channel Blockers

There are many different generic and brand-name forms of calcium channel blockers available, including:

  • diltiazem (Cardizem, Cartia, Dilacor XR, Diltia XT, Tiamate)
  • verapamil (Calan, Covera-HS, Isoptin, Verelan)
  • nifedipine (Adalat, Procardia, Procardia XL)
  • nicardipine (Cardene)
  • nimopidine (Nimotop)
  • amlodipine (Norvasc, Lotrel)
  • nisoldipine (Sular)
  • isradipine (Dynacirc)
  • bepridil (Vascor)
  • felodipine (Plendil)

Typical Calcium Channel Blocker Interactions

Calcium channel blockers may interact with other medications, so always tell your doctor about every medication, recreational drug, vitamin, and supplement — whether over-the-counter (OTC) or prescription — that you are taking.

Most calcium channel blockers should be taken with a meal or a glass of milk to protect the stomach. Talk to your doctor about what is best for you.

You should not, however, take calcium channel blockers with grapefruit juice or grapefruit.

Grapefruit (and its juice) can alter the effects of many drugs, including calcium channel blockers, according to the Cleveland Clinic.

Some of the drugs that are likely to interact with calcium channel blockers include:

Remember to take calcium channel blockers exactly as your doctor or pharmacist recommends.

This means not crushing, chopping, or dissolving these medications unless you’re told it’s okay — especially if you’re taking a medication that ends in XL or XR, which means extended release.

Cutting pills will negate that effect, and possibly cause adverse effects.

Calcium Channel Blocker Side Effects

It’s also important to avoid drinking alcohol when taking calcium channel blockers.

Alcohol, combined with a calcium channel blocker, can cause severe side effects and may also affect the way the medication works.

Side effects from taking calcium channel blockers are usually fairly mild but, according to the Mayo Clinic, may include:

  • Weight gain
  • Swelling in the lower legs, feet, or ankles
  • Feeling dizzy
  • An increase in appetite
  • Constipation
  • Feeling tired or drowsy
  • A heartbeat that feels rapid, slow, or irregular
  • Coughing, wheezing, or problems with breathing or swallowing
  • Nausea or stomach discomfort
  • Numbness or a tingling sensation in the feet or hands

Calcium channel blockers are generally safe, but like any medication, need to be taken properly and with care.

To lessen the chance of interactions, always tell your doctor about other medications you’re taking.

And remember that you don’t have to deal with side effects: Talk to your doctor about them.

Chances are that a slight adjustment in the dosage or the way you take your medication will help you feel better while allowing you to get the treatment you need.

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Stephanie Young Moss, PharmD

Medical Reviewer

Stephanie Young Moss, PharmD, has worked in pharmacy, community outreach, regulatory compliance, managed care, and health economics and outcomes research. Dr. Young Moss is the owner of Integrative Pharmacy Outcomes and Consulting, which focuses on educating underserved communities on ways to reduce and prevent health disparities. She uses her platform to educate families on ways to decrease and eliminate health disparities by incorporating wellness and mental health techniques.

Young Moss is the creator of the websites DrStephanieYoMo.com and MenopauseInColor.com, providing practical health and wellness tips and resources for women experiencing perimenopause and menopause. She has over 100,000 people in her social media communities. She has also contributed to Pharmacy Times and shared her views on international and national podcasts and local television news.

She has served on various boards for organizations that focus on health equity, decreasing implicit bias, addressing social determinants of health, and empowering communities to advocate for their health. She has also been on the boards for the Minority Health Coalition of Marion County and Eskenazi Health Center, for which she was the clinical quality committee chair and board secretary and is currently the board treasurer. She is a board member for Community Action of Greater Indianapolis.

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Diana Rodriguez

Author

Diana Rodriguez is a full-time freelance writer with experience writing health-related news and feature stories. She is skilled in taking confusing doctor-speak and complex medical topics and crafting language that's easy for readers to understand. She is a managing editor at the Mayo Clinic and has written extensively for HealthDay. She lives in Louisville, Kentucky and holds a bachelor's degree in journalism and French from Miami University.

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