Heart Disease: Calcium Channel Blocker Drugs

Calcium channel blockers are drugs that relax blood vessels and increase the supply of blood and oxygen to the heart -- while also reducing the heart's workload. Examples of calcium channel blockers include:

• Norvasc (amlodipine)
• Plendil (felodipine)
• Cardizem, Cardizem CD, Cardizem SR, Dilacor XR, Diltia XT, Tiazac (diltiazem)
• Calan, Calan SR, Covera-HS, Isoptin, Isoptin SR, Verelan, Verelan PM (verapamil)
• Adalat, Adalat CC, Procardia, Procardia XL (nifedipine)
• Cardene, Cardene SR (nicardipine)
• Sular (nisoldipine)
• Vascor (bepridil)

Caduet is a combination of a statin cholesterol drug and amlodipine (above).

For What Conditions Are Calcium Channel Blockers Prescribed?

• High blood pressure (when other medications to lower blood pressure are ineffective)
• Coronary artery disease
• Coronary spasm
• Angina (chest pain)
• Abnormal heart rhythms
• Hypertrophic cardiomyopathy
• Diastolic heart failure (preserved left ventricular function)-generally, a calcium channel blocker should NOT be used if you have heart failure due to systolic dysfunction

Calcium channel blockers are also used to treat migraine headaches.

How Should I Take Calcium Channel Blockers?

Take this medication with food or milk. Follow the label directions on how often to take it. The number of doses you take each day, the time allowed between doses and how long you need to take it will depend on the type of medication prescribed and on your condition.

While taking this medication, have your blood pressure checked regularly, as advised by your doctor.

While taking this medication, your doctor may tell you to take and record your pulse daily. Your doctor will tell you how rapid your pulse should be. If your pulse is slower than advised, contact your doctor or nurse about taking your calcium channel blocker that day.

What Are the Side Effects?

Side effects can include:

• Drowsiness.
• Increased appetite.
• Weight gain: call your doctor right away.
• Breathing difficulties (shortness of breath, coughing, or wheezing): call your doctor right away.
• Irregular or slow heartbeat: call your doctor right away.
• Allergic reaction (skin rash or hair loss): call your doctor right away.
• Constipation.
• Tenderness or bleeding of the gums.
• Swelling of feet, ankles and legs.
• Fainting.

Talk to your doctor if any of these side effects (drowsiness, increased appetite, constipation, tenderness or bleeding of the gums, swelling of feet, ankles, and legs, or fainting) are persistent or severe.

Should I Be Concerned About Food and Drug Interactions?

Do not eat grapefruit or drink grapefruit juice while taking a calcium channel blocker.

Avoid alcohol, as it interferes with the effects of calcium channel blockers and increases the side effects.

It is important that your doctor is aware of all the medications you are taking, as some may have the potential to interact with calcium channel blockers. Talk to your doctor before taking any new medication, including over-the-counter drugs, herbs and supplements.

Can Pregnant Women Take Calcium Channel Blockers?

Consult with your doctor before taking calcium channel blockers during pregnancy. Animal studies suggest that they may cause birth defects and even stillbirth (baby is not alive at birth).

These drugs may also pass into breast milk, but no effect on breastfed infants has been found.

Can Children Take Calcium Channel Blockers?

The safety of these drugs in children has not been established; however, no problems have been found to date. Discuss the risks and benefits of giving your child calcium channel blockers with your child's doctor.

Can Elderly People Take Calcium Channel Blockers?

Older adults have more side effects from calcium channel blockers than younger people. As a result, lower doses are frequently prescribed.

Reviewed by the doctors at The Cleveland Clinic Heart and Vascular Institute (2005).