Is Calcium Safe with Atenolol?
Free · No account · based on published sources including NIH ODS, FDA drug labels, and peer-reviewed literature
Do not take calcium supplements within 2 hours of your Atenolol dose. This is especially important on an empty stomach. Consult your pharmacist for optimal dosing schedule.
Why this interaction occurs
Studies have shown that calcium carbonate can reduce Atenolol bioavailability by approximately 50% when taken simultaneously, potentially diminishing its antihypertensive and anti-anginal efficacy due to chelation and reduced GI absorption.
Evidence
Evidence level: strong.
Reported safety data
The FDA’s adverse event reporting system (FAERS) has received 128,375 reports mentioning Atenolol. This reflects reported cases involving the medication in general — not confirmed causation, and not specific to the Atenolol + supplement combination on this page.
FAERS reports are voluntary and cannot prove that a drug caused an event. Do not use report counts to assess the safety of this specific drug-supplement pair.
Frequently asked questions
Related interactions
All Calcium interactions → · All Atenolol interactions →
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Educational only — not medical advice.
Always confirm with your doctor or pharmacist.