Calcium-channel blockers are a class of medications indicated for the treatment of high blood pressure, chest pain or angina and irregular heartbeats. They slow the rate of calcium movement across vessel walls, which in turn slows heart rate and relaxes blood vessel walls to increase blood flow and lower blood pressure. Calcium-channel blockers may cause side effects, and several different types of medications interact negatively with them.
Side Effects
Calcium-channel blockers can cause mild and serious side effects in some individuals. Common side effects include heartburn, drowsiness, flushing and swelling of the abdomen and legs. Less common side effects include changes in hear rate, shortness of breath, dizziness, constipation and numbness in the hands or feet. Rare side effects include headache, fainting, yellowing of the skin and whites of the eye, fever and bleeding of the gums, according to the Texas Heart Institute.
Drug Interactions
Many drugs should not be used in combination with calcium-channel blockers as they may cause unwanted side effects or complications. Medications that can increase or decrease the effects of calcium-channel blockers include irregular heartbeat treatment medications, diuretics or water pills, corticosteroids and high doses of calcium or vitamin D supplements. Other blood pressure lowering medications such as beta-blockers and ACE inhibitors may also interact with calcium-channel blockers, according to the Texas Heart Institute.
Smoking and Drinking
Smoking and drinking alcohol should be avoided while taking calcium-channel blockers. Smoking in combination with calcium-channel blockers may lead to tachycardia or a rapid heartbeat. Tachycardia may increase the risk of blood clots, heart failure, fainting and sudden death, according to the Mayo Clinic. Drinking alcohol while on calcium-channel blockers can increase the effects of side effects and further lowers blood pressure leading to light-headedness and dizziness, fainting and blurred vision, among other symptoms.
