Calcium channel blockers are a category of medication used to treat hypertension. They work by preventing calcium from entering the cells of the heart and blood vessels, leading to a decrease in blood pressure. According to the Texas Heart Institute, they are also used to control chest pain and irregular heartbeats. Before taking calcium channel blocker anti-hypertensive medication you should tell your doctor if you are pregnant or thinking about becoming pregnant, if you have low blood pressure, low blood sugar or Parkinson's disease. You doctor may consider other medication if you have heart failure, history of kidney or liver disease or are over 60 years old.
Orthostatic Hypotension
Calcium channel blockers can cause a drop in blood pressure, according to Bupa. You may experience dizziness when you stand suddenly from a seated or lying position. Until you know how the medication will affect you, do not drive or operate other heavy machinery. To prevent falls you can get up slowly and stand next to the bed or chair for a minute or two, until you are sure you will not get dizzy.
Bradycardia
Calcium channel blockers can also cause bradycardia, which is the medical term for a slow heart rate, according to Bupa. A slow heart rate can be the result of a well-trained and fit heart or can be a sign of a problem. When it is caused by medication you can feel dizzy, lightheaded, short of breath, tired, have chest pain or have trouble concentrating as your heart is not able to pump enough oxygen throughout your body and to your brain.
Gastrointestinal Distress
Calcium channel blockers can cause gastrointestinal disturbances that can be uncomfortable, according to the Mayo Clinic. These symptoms include nausea, stomach upset and constipation but do not seem to impact metabolism. You may find that these symptoms subside as you take the medication for more than two weeks. Some people find that these side effects do not disappear with long-term administration. You can increase your fluid and fiber intake to decrease the side effects of constipation.
Grapefruit Interaction
Calcium channel blockers will interact with grapefruit, according to the Mayo Clinic. Any grapefruit products or supplements that contain grapefruit can interfere with the ability of your liver to eliminate the medication from your body. This will increase the amount of medicine and increase your risk of overdose.
