Types of medicine
What Is a Calcium Channel Blocker?
Calcium Channel Blocker · say it: KAL-see-um CHAN-ul BLOK-erAlso written: CCB, calcium antagonist, calcium blocker
Short answer
A calcium channel blocker is a type of medicine, such as amlodipine, that relaxes blood vessels and is used for high blood pressure and angina.
What it means
Calcium channel blockers (CCBs) reduce the flow of calcium into the muscle cells of the heart and blood vessels. This relaxes and widens blood vessels, and some types also slow the heart rate. Examples include amlodipine and nifedipine, which act mainly on blood vessels, and verapamil and diltiazem, which also act on the heart. They are used for high blood pressure, angina and some heart rhythm problems.
Labels mention common effects such as ankle swelling, flushing, headache and dizziness. Some CCB labels warn about grapefruit juice and CYP3A interactions, and verapamil and diltiazem labels warn about combining with beta-blockers or other medicines that slow the heart.
Calcium channel blockers do not affect the calcium in your bones or diet in the way the name might suggest. You do not need to avoid calcium foods or supplements because of them, unless your doctor says so for another reason.
Where you may see it
- Blood pressure and angina medicine labels
- Leaflets under 'Other medicines and this medicine'
- Cardiology clinic letters
📄 How it looks on a report
Peripheral edema is the most commonly reported adverse reaction and is dose-related.
🙅 What it does not mean
- They do not lower the calcium in your bones or blood.
- Ankle swelling with a CCB is not always a sign of heart failure, but it should be mentioned to your doctor.
- Different CCBs are not all interchangeable; some act more on the heart than others.
🗒️ Questions to ask your doctor
💊 Medicines whose labels mention “Calcium Channel Blocker”
Plain-English explanations of each medicine, from its official FDA label.
- Amlodipine
a calcium channel blocker, a type of medicine that relaxes blood vessels
- Nifedipine
a calcium channel blocker of the dihydropyridine type
🔗 Read more from trusted sources
- “Calcium Channel Blocker” on MedlinePlus ↗
US National Library of Medicine
- NCI Dictionary definition ↗
US National Cancer Institute: “calcium channel blocker”
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