calcium channel blocker

A calcium channel blocker is any of a class of pharmaceuticals used in the treatment of angina pectoris (chest pain due to an inadequate blood supply to heart muscle), high blood pressure (hypertension), and certain types of cardiac arrhythmias (irregular heartbeat). Calcium channel blockers are a type of vasodilator.


How calcium channel blockers work

In the treatment of angina and high blood pressure, calcium channel blockers (CCBs) work by interfering with muscle contraction. They prevent the movement of calcium ions across the membrane that lines muscle cells, which is an essential part of the mechanism of muscle contraction. This action decreases the work of the heart in pumping blood, reduces the pressure of blood flow through the body, and improves the circulation of blood through heart muscle.


Calcium channel blockers also slow the passage of nerve impulses through heart muscle, which helps correct certain types of arrhythmias.


Possible adverse effects

Adverse effects of calcium channel blockers are mainly related to their action of increasing blood flow through tissues. These effects include headaches, facial flushing, and dizziness (usually on standing). Such effects, however, disappear with continued treatment.


Commonly prescribed calcium channel blockers

The specific ingredients in each type of calcium channel blocker vary. However, the main ingredient is called a calcium channel antagonist. This helps decrease the heart's pumping strength, which relaxes the blood vessels. Commonly prescribed types and brands are:


  • Amlodipine (Norvasc)
  • Bepridil (Vascor)
  • Diltiazem (Cardizem, Dilacor)
  • Felodipine (Plendil)
  • Isradipine (DynaCirc)
  • Nicardipine (Cardene)
  • Nifedipine (Adalat, Procardia)
  • Nimodipine (Nimotop)
  • Verapamil (Calan, Isoptin, Verelan)