As blood moves through the body's network of arteries, veins and capillaries it pushes against the arterial walls, a force measured as blood pressure. High blood pressure results from the tightening of small arteries, causing the heart to work harder as it pumps blood through smaller spaces, increasing the pressure inside the vessels. High blood pressure can cause hardening of the arteries, an enlarged heart as well as kidney or eye damage.
Calcium Can Sometimes be a Culprit
All cells in the body need calcium and all muscles need calcium to contract. But in some cases, excess calcium can lead to adverse effects. The movement of calcium into the cells of the blood vessels causes them to narrow, or contract, making if more difficult for the heart to pump blood through constricted vessels. This results in an increase in the pressure inside the blood vessels, a condition known as hypertension, or high blood pressure.
Calcium Channel Blockers Lower Blood Pressure
Calcium channel blockers are drugs used to lower blood pressure. They adhere to the surface membranes in blood vessel walls and restrict some of the calcium from entering the cells of the vessels. This slowing of the movement of calcium into the blood vessel walls causes the vessels to relax and open wider, making it easier for blood to flow through the vessels, thus lowering blood pressure.
Types of Calcium Channel Blockers
These drugs are classified into two basic types, dihydropyridine and non-dihydropyridine. Non-dihydropyridine calcium channel blockers such as diltiazem and verapamil are used to treat malfunctions of the heart such as relieving angina and stabilizing arrhythmias. Dihydropyridine calcium channel blockers such as amlodipine, felodipine, isradipine, lacidipine, lercanidipine, nicardipine, nifedipine, and nimodipine work primarily by relaxing and dilating blood vessels, thereby reducing blood pressure, states Patient UK.
Side Effects
Like other blood pressure-lowering medications, calcium channel blockers also have some potential side effects. The most common side effects caused from using these medicines include dizziness, stomach pain, constipation, irregular heart rhythm, hot flashes, dry mouth, headache, nausea, fatigue and swelling or water retention in the hands, feet or legs.
Precautions
Patients taking calcium channel blockers are advised not to eat grapefruit or drink grapefruit juice within two hours prior to or four hours after taking these medications, notes MayoClinic.com. Interactions with grapefruit or grapefruit juice hinder the body's capacity to clear these drugs from the system, allowing them to build up in the body, causing potentially serious side effects. Alcohol should not be consumed while taking a calcium channel blocker because it modifies the effects of the drug and increases the side effects, states the Cleveland Clinic. Taking other blood pressure medications in combination with a calcium channel blocker may cause a sudden and dangerous drop in blood pressure.
