The intrinsic rhythm of the heart is governed by a number of so called “ion channels”. These channels allow ions, such as sodium, calcium, potassium and chloride to move in and out of the heart cell. Calcium in the cell is essential for contraction of the muscle. A certain group of drugs called calcium channel blockers (CCBs) decrease not only this rapid influx of calcium in the heart cells, but also in the smooth muscle cells, which ring the arteries and arterioles of the body.
Types of CCBs
Broadly speaking, there are two main types of calcium channel blockers.
Dihydropyridine (such as Nifedipine & Amlodipine)
Non Dihydropyridine (such as Diltiazem and Verapamil)
Who might need CCBs
Angina: there may well be patients who are unable to tolerate Beta blockers due to side effects, such as exacerbation of lung disease or asthma, tiredness or coldness with the peripheries. In these individuals, the cardiologist may often choose to use a rate limiting calcium channel blocker, such as Verapamil, to slow down the heart rate and have a similar effect to Beta blockade. Frequently, the cardiologist will use a combination of Beta blockade and Calcium channel blockers in the treatment of Angina.
Hypertension: they are excellent drugs for use in certain individuals.