Calcium is necessary for the function of all muscle cells in the body. Calcium channels in cardiovascular tissue help regulate heart muscle and blood vessel contractions. Calcium channel blockers, or CCBs, reduce the amount of calcium entering the heart muscle and the smooth muscle walls of blood vessels. They are used to treat high blood pressure, heart rhythm problems and chest pain called angina.
Reduced Blood Pressure
When the smooth muscle cells in the walls of arteries contract, they cause the arteries to narrow. CCBs reduce the flow of calcium into the smooth muscle, causing the arteries to relax and widen. When blood vessels widen, the force of the blood against the vessel wall is reduced lowering blood pressure.
Rhythm and Rate Control
Calcium is a critical component of the heart's electrical conduction system. Signals flow between heart muscle cells, producing contractions. These contractions enable the heart to pump blood throughout the body. Calcium channel blockers slow the conduction system of the heart, reducing contractions and controlling abnormally rapid beats, according to Rxlist.com.
Reduced Oxygen Demand
By slowing the rate of heart beats and dilating the blood vessels, CCBs lower the work load of the heart, reports CV Pharmacology. This reduces the heart's demand for oxygen. Arterial wall relaxation promotes blood flow, increasing the supply of oxygen to the heart. Providing more oxygen to the heart while lowering its demand helps treat the chest pain associated with cardiovascular disease.
Negative Effects
Some of the more common negative effects of CCBs include nausea, headache, constipation, flushing, swelling in the ankles, dizziness and drowsiness.
