What are the side effects of calcium channel blockers?

Calcium channel blockers block the influx of ions into cells, so calcium (that's the ion that gets blocked) can't rush into cells. This makes these drugs useful in treating high blood pressure and a rapid heart rate. Side effects of calcium channel blockers sometimes are problematic. These include:

  • Constipation - Because calcium channel blockers prevent calcium ions from influxing into cells, one of the places that prevent them from influxing is into the muscles that make your gut contract. So constipation can be a real problem for people who take calcium channel blockers. And sometimes it's actually debilitating.
  • Headache - Headaches are common, as they are with beta blockers and alpha blockers.
  • Lower extremity swelling (specifically feet and ankles) - This is not actually harmful, but it sure makes walking hard.

Side effects of calcium-channel blockers include fatigue, dizziness, constipation, and swelling of the feet. Calcium-channel blockers may not be the best choice for people with heart failure or heart rhythm abnormalities.

Donna Hill Howes, RN
Family Practitioner

Side effects may include headaches, dizziness, general weakness, fatigue, flushing, nose and throat inflammation, changes in heart rate, skin rash, swelling of the legs or feet, nausea, constipation, and diarrhea. 

This answer was adapted from Sharecare's award-winning AskMD app. Start a consultation now to find out what's causing your symptoms, learn how to manage a condition, or find a doctor. 

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.