Calcium Channel Blockers for Hypertension

Medically reviewed by Alan Carter, PharmD on February 10, 2016Written by Erica Roth

Calcium channel blockers (CCBs) are a class of medications used to treat high blood pressure. They’re also called calcium antagonists and are as effective as angiotensin converting enzyme (ACE) inhibitors in reducing blood pressure. CCBs can differ in the following ways:

  • how long they last
  • how they’re eliminated from the body
  • how they affect heart rate

Find the Best Calcium Channel Blockers for High Blood Pressure »

Who Should Take Calcium Channel Blockers?

People who have high blood pressure, irregular heartbeats called arrhythmias, or chest pain related to angina may be prescribed a CCB as treatment. High blood pressure can also be treated with other forms of medication. You could be asked to take both a CCB and another hypertensive drug at the same time.

How They Work

CCBs reduce blood pressure by limiting the amount of calcium or the rate at which calcium flows into the heart muscle and arterial cell walls. Calcium stimulates the heart to contract more forcefully. When calcium flow is limited, your heart’s contractions aren’t as strong and your blood vessels are able to relax, leading to lower blood pressure.

CCBs are available in a number of oral formats, ranging from short-acting dissolving tablets to extended-release capsules. The dosage will depend on your overall health and medical history. Your doctor will also take your age into consideration before prescribing a blood pressure-lowering medication. CCBs are most effective and less likely to cause side effects in people over the age of 65. The classes of CCB drugs are:

  • L-type
  • dihydropyridines
  • non-dihydropyridines

Dihydropyridines are more commonly used to treat hypertension than L-type or non-dihydropyridine drugs. This is due to their ability to reduce arterial pressure and vascular resistance. Dihydropyridine calcium antagonists usually end in the suffix “-pine” and include:

Other commonly prescribed CCBs used to treat angina and a rapid heartbeat are verapamil, bepridil, and diltiazem.

ACE inhibitors, diuretics, and beta-blockers also lower blood pressure. These drugs are generally more effective at treating hypertension than CCBs. However, African-Americans may benefit more from CCBs as a first line treatment for high blood pressure.

Side Effects and Risks

CCBs may interact with other drugs or supplements you take. Make sure that your doctor has an updated list of all of your medications, vitamins, and herbal supplements. CCBs and grapefruit products, including whole fruit and juice, shouldn’t be taken together. Grapefruit products interfere with the normal excretion of the medication. It could be potentially dangerous if large amounts of the drug accumulate in your body.

Wait at least four hours after you’ve taken your medication before drinking grapefruit juice or eating grapefruit. Refrain from smoking when taking CCBs because a rapid heartbeat can result. Other side effects of CCBs include:

  • dizziness
  • a headache
  • constipation
  • heartburn
  • nausea
  • a skin rash or flushing, which is redness of the face
  • edema, or swelling, in the lower extremities
  • fatigue

CCBs also lower blood glucose levels in some people, particularly those whose dosage is higher than 60 milligrams per day. Tell your doctor about any side effects you’re experiencing. They may adjust your dosage or recommend that you switch to another medication if the side effects are prolonged, uncomfortable, or pose a threat to your health.

Natural Calcium Channel Blockers

Magnesium is an example of a nutrient that acts as a natural CCB, as detailed in a study published in a 1984 issue of the American Heart Journal. Magnesium is an electrolyte, which is a mineral that holds an electrical charge in the body and helps regulate fluid levels. Magnesium is essential for protein and antioxidant synthesis and can be beneficial to cardiac health and the regulation of blood pressure levels. Magnesium-rich foods include:

  • brown rice
  • almonds
  • peanuts
  • hazelnuts
  • oat bran
  • shredded wheat cereal
  • bananas
  • spinach
  • okra
  • blackstrap molasses

Ask your doctor if eating foods high in magnesium will affect the potency of the CCBs you’re taking. 

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