Calcium Channel Blockers for Hypertension

Calcium channel blockers (CCB) are a common class of medication used to treat high blood pressure and heart arrhythmias (irregular heartbeats). Calcium is a mineral that is vital for heart muscle contraction and for regulating the tone of the muscles in the walls of the arteries. CCBs work by reducing the amount of calcium that flows into the heart muscle cells and the cell walls of the arteries. This relaxes the blood vessels to reduce hypertension (high blood pressure).

CCBs can be used in combination with other medications to lower blood pressure.

This vasodilatory (widening the arteries) effect is also used to prevent angina, which is chest pain that occurs when arteries in the heart are blocked. Narrow arteries are one of the biggest causes of angina, making the vasodilatory effect so important.

CCBs can also lower the heart rate and decrease the heart's pumping action.

The research of all available evidence by JNC 8 (Joint National Commission 8) has demonstrated that CCBs are particularly advantageous for the initial treatment of high blood pressure in African-American people.

However, doctors agree that the amount of blood pressure reduction achieved, and not the specific drug or drugs used, reduces cardiovascular risk in people with hypertension. The optimal treatment for hypertension must be individualized for everyone.

There Are Different Types of Calcium Channel Blockers

There are three different classes of CCBs, which include L-type, dihydropyridines, and non-dihydropyridines. Each class has different characteristics that make them suitable for the treatment of specific conditions.

• Dihydropyridines are used to treat high blood pressure more frequently than the other classes of CCBs. This is because they work well to reduce arterial blood pressure and vascular resistance. The names of drugs in this class usually end with the suffix "-pine."
• Other CCBs, including diltiazem and verapamil, are used to treat rapid heart rates and angina.
• CCBs are sometimes prescribed in combination forms with a statin or another blood pressure medication.

Examples of Calcium Channel Blockers

There are are several CCBs that include generic brands, according to Kaiser Permenante and include:

• Calan, Verelan (verapamil)
• Norvasc (amlodipine)
• Tiazac, Cardizem, Dilacor (diltiazem)
• Procardia (nifedipine)
• Cardene (nicardipine)
• Lotrel (amlodipine/benazepril)
• Caduet (amlodipine/atorvastatin)
• Exforge (amlodipine/valsartan)

Cautions of Calcium Channel Blockers

When taking CCBs, you should be certain your healthcare provider knows about all of your current medications and supplements, because CCBs can interact with other compounds.

Special precautions:

• Grapefruit: Grapefruit products, including juice, can interfere with the metabolism and excretion of these medications, which can result in dangerously high levels of the drugs. If you are taking a CCB, you should wait at least four hours after taking the medication before consuming grapefruit or grapefruit juice.
• Magnesium: This nutrient is found in certain nuts, bananas, spinach, okra, brown rice, and shredded wheat cereal, has natural CCB effects. So if your diet includes foods rich in magnesium, check with your healthcare provider to determine if any adjustment is needed. 
• Smoking: You should not smoke when taking a CCB, as this could result in a potentially dangerous rapid heartbeat. 

Side Effects Associated With Calcium Channel Blockers

Several side effects can occur with calcium CCBs, but they do not appear in all patients, and the benefits of therapy are more significant than the risk of side effects. The most common side effects include fatigue, flushing, swelling of the abdomen, ankles, or feet, and heartburn, according to the Texas Heart Institute, while less common side effects include:

• Very fast or very slow heartbeat
• Wheezing, coughing, or shortness of breath
• Trouble swallowing
• Dizziness
• Numbness or tingling in the hands or feet
• Upset stomach
• Constipation

Rare side effects:

• Headache
• Fainting
• Chest pain
• Yellowing of the skin or eyes (jaundice)
• Fever
• Rash
• Bleeding, swollen, or tender gums
• Vivid dreams

If you notice any side effects, consult your healthcare provider before stopping the medication. Stopping medication suddenly is never a good idea. Your healthcare provider will be able to advise you about alternatives, including a different dose or different medications.