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Calcium Channel Blockers


Updated December 08, 2006


Calcium channel blockers are a safe and effective drug used to treat high blood pressure. These drugs are primarily active on the cardiovascular and circulatory system, and are thus also used to treat things like

  • Angina
  • Some types of abnormal heart rhythms

Unlike other drugs used to treat high blood pressure, calcium channel blockers are generally not given to people who have heart failure or actual physical damage to the heart muscle.

How They Work:

The general action of calcium channel blockers is very analogous to that of beta blockers. Namely, these medicines work by attaching to the target of a specific chemical signal and preventing the signal from reaching and activating that target.

In this case, the end result is that calcium is prevented from entering muscle cells, which, in turn, decreases the amount of force the muscle can generate when contracting.

The specifc targets blocked by calcium channel blockers exist in high numbers both on blood vessels and in the heart, allowing the drug to exhert most of its influence in these areas

Common Names:

Many different calcium channel blockers are currently available. Though these drugs have different names, they are all the same type of drug, and they work in an identical way. Common calcium channel blockers include:

  • Diltiazem
  • Amlodipine
  • Verapamil
  • Nifedipine
Other calcium channel blockers are available, and not all calcium channel blockers are sold in the United States. Please talk with your pharmacist if you have a question about the availability of a specific calcium channel blocker.

Side Effects:

All medicines carry some risk of side effects. If you are taking a calcium channel blocker and experience any side effects, notify your doctor at once. Some reported side effects include:

  • Drowsiness
  • Increased Appetite
  • Weight Gain
  • Diarrhea
  • Flushing
  • Nausea

Many calcium channel blockers have specific dosing and administration requirements with which you need to be familiar. For example, some calcium channel blockers cannot be taken with any acidic food or liquid (e.g., grapefruit juice), some must be taken at the same time each day, etc. Ask for help if you need clarification regarding proper use of your medicine.


Only you and your doctor can decide on a proper medication for treatment of high blood pressure. Be sure to notify your doctor if you are pregant or breast feeding, and to supply the names of any other medicines and/or suppliments you are taking. Remember to include over the counter medicines like aspirin or Advil and herbal/natural suppliments. If you're eating or drinking anything that isn't food, it is always a good idea to tell your doctor.

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  5. Calcium Channel Blockers

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