Calcium × Tetracyclines
MODERATE
Well-Established Evidence
Mechanism
Calcium chelates tetracycline antibiotics, forming insoluble complexes that reduce absorption.
Effect
Reduced tetracycline absorption and efficacy
Management
Separate doses by at least 2 hours before or 4 hours after tetracycline.
Plain Language Summary
AI-generated · Qwen 3.6 · grounded in 2 sources · methodologyThis combination requires caution because calcium can bind to tetracycline antibiotics, which prevents your body from absorbing the medicine properly. This interaction may make the antibiotic less effective at treating an infection.
Source
FDA tetracycline labeling; Neuvonen PJ. Drugs 1976
Research
Supporting Research
First-line drugs for hypertension
Beta-blockers for hypertension
Calcium channel blockers versus other classes of drugs for hypertension
Effect of early treatment with anti-hypertensive drugs on short and long-term mortality in patients with an acute cardiovascular event
Phlebotonics for venous insufficiency
Calcium channel blockers versus other classes of drugs for hypertension
Calcium supplementation for prevention of primary hypertension
Calcium supplementation for prevention of primary hypertension
Medical Disclaimer: This interaction record is for informational and educational purposes only and does not constitute medical advice. Always consult your healthcare provider or pharmacist before combining any supplement with prescription medications.