Calcium Channel Blocker Drug Information
(CCBs)

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Pharmacy Author:

Annette (Gbemudu) Ogbru, PharmD, MBA

Annette (Gbemudu) Ogbru, PharmD, MBA

Dr. Gbemudu received her B.S. in Biochemistry from Nova Southeastern University, her PharmD degree from University of Maryland, and MBA degree from University of Baltimore. She completed a one year post-doctoral fellowship with Rutgers University and Bristol Myers Squibb.

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Medical Editor:

Jay W. Marks, MD

Jay W. Marks, MD

Jay W. Marks, MD, is a board-certified internist and gastroenterologist. He graduated from Yale University School of Medicine and trained in internal medicine and gastroenterology at UCLA/Cedars-Sinai Medical Center in Los Angeles.

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• What are calcium channel blockers (CCBs) and how do they work?
• For what conditions are calcium channel blockers used?
• Are there any differences among calcium channel blockers?
• What are the side effects of calcium channel blockers?
• With which drugs do calcium channel blockers interact?
• What are examples of calcium channel blockers available?

What are calcium channel blockers (CCBs) and how do they work?

Calcium channel blockers are drugs that block the entry of calcium into the muscle cells of the heart and arteries.

• The entry of calcium is critical for the conduction of the electrical signal that passes from muscle cell to muscle cell of the heart, and signals the cells to contract.
  
  
• It also is necessary in order for the muscle cells to contract and thereby pump blood.
  
  
• In the arteries, the entry of calcium into muscle cells causes contraction of the cells and thereby dilates (widens) the arteries.
  
  
• Thus, by blocking the entry of calcium, calcium channel blockers reduce electrical conduction within the heart, decrease the force of contraction (work) of the muscle cells, and dilate arteries.
  
  
• Dilation of the arteries reduces blood pressure and thereby the effort the heart must exert to pump blood.
  
  
• Combined with decreases in the force of contraction, this leads to a reduced requirement for oxygen by the heart.
  
  
• Dilation of the arteries provides more oxygen-carrying blood to the heart.
  
  
• The combination of reduced demand for oxygen and increased delivery of oxygen prevents angina or heart pain. (Angina occurs when the heart is not getting enough oxygen relative to the amount of work it is doing.)
  
  
• In addition, calcium channel blockers slow electrical conduction through the heart and thereby correct abnormal rapid heartbeats.