Calcium channel blockers

Calcium channel blockers lower your blood pressure. Some calcium channel blockers have the added benefit of slowing your heart rate, which can further reduce blood pressure, relieve chest pain (angina), control an irregular heartbeat (e.g. atrial fibrillation).

Types of calcium channel blockers

  • Felodipine e.g. Plendil ER
  • Amlodipine e.g. Vasorex, Auro-Amlodipine, Norvasc, Ozlodip
  • Diltiazem e.g. Apo-Diltiazem, Cardizem CD, Dilzem
  • Nifedipine e.g.  Adalat, Nyefax Retard, Adalat Oros Nifehexal, Adefin XL
  • Verapamil e.g. Isoptin

How do they work?

Calcium channel blockers get their name because they prevent calcium from entering cells of the heart and blood vessel walls. Calcium normally travels through channels into the muscle cells to help with muscle activation. By blocking some of these channels the medications relax your blood vessels, making them wider, which lowers blood pressure.

This should not be confused with dietary calcium or even the calcium deposited in the lining of blood vessels which are different processes and unaffected by these medications.

What's the catch?

You may experience some unwanted side effects when taking calcium channel blockers. These can include:

  • Swelling of the ankles or feet
  • Feeling tired or dizzy
  • Heartburn
  • Constipation
  • Skin rashes
  • Swollen or bleeding gums (rarely).

If you are taking certain calcium channel blockers you should not eat grapefruit or drink grapefruit juice. This is because there is a chemical in grapefruit and grapefruit juice that interferes with the amount of medicine that enters your blood stream. Talk to your doctor or pharmacist to see if this applies to you. 

What checks do I need?

You are likely to have regular blood pressure and heart rate checks while taking calcium channel blockers. ​

Taking medication

Related treatments and conditions

AnginaAtrial fibrillationArrhythmiaBlood pressureHeart attack

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