Calcium channel blocker describes a classification of medications doctors prescribe to treat several different cardiovascular conditions that affect the heart and blood vessels. Although generic medications often provide the advantage of cost savings, as indicated by the Consumer Reports Health website, depending on the condition and the symptoms, many doctors prefer for patients to take brand-name drugs.
Role of Calcium
Cells require a delicate balance of minerals in order to function properly. Muscle cells, which include those muscle cells contained in the heart, need calcium in order to contract and magnesium in order to relax. Heart muscle cells store calcium in a structure known as the sarcoplasmic reticulum, or SR. Electrical impulses in the heart signal a specialized protein in the SR, known as the calcium pump, to release calcium into the main body of the cell, which then stimulates the cell to contract. Because each cell is interconnected, all cells contract in unison, as described by the Cells Alive website.
Mechanism of Action
Conditions that damage the cells and affect the ability of the SR to hold calcium or the ability of the calcium pump to operate allow too much calcium to remain in the body of the cell. This interferes with the cell's ability to respond appropriately to the electrical impulses, leading to weak contractions. As calcium accumulates in the cell, it can lead to cell death, which contributes to the onset of a variety of conditions. Calcium channel blockers slow the rate at which calcium enters the cells of the heart and the blood vessels, according to the Texas Heart Institute.
Conditions
Doctors commonly prescribe calcium channel blockers to treat high blood pressure, angina and arrhythmia. High blood pressure, a condition known as hypertension, causes the pressure the blood exerts on the walls of the blood vessels to increase. Over time, high blood pressure damages the walls of blood vessels and can affect their ability to pump calcium appropriately. Angina, also known as chest pain, occurs when the heart muscle fails to receive enough blood and oxygen. Arrhythmia, or irregular heartbeats, occurs when the heart muscle cells fail to contract in unison. Calcium channel blockers relax the walls of blood vessels, allow the vessels to dilate and slow the heart rate.
Brand Names
Several different types of calcium channel blockers are available; some contain different concentrations of medicine and others offer extended release. Norvasc, the brand name for the medication amlodipine, can be purchased in different concentrations. Several brand-name medications contain the generic medication diltiazem, including Cardizem LA, Dilacor XR and Tiazac. The brand-name medications Procardia, Procardia XL and Adalat CC all contain the generic drug nifedipine, whereas Calan Verelan and Covera-HS contain the drug verapamil. Other brand-name calcium channel blockers include Plendil, Cardene, Cardene SR and Sular.
Side Effects
The effects of calcium channel blockers on cells throughout the body can result in a variety of side effects. Common side effects include fatigue; flushing; heartburn; headache; and swelling of the abdomen, hands or feet. Other side effects that occur less commonly include constipation, dizziness, numbness, rapid heartbeat, shortness of breath and upset stomach with nausea.
