MajorFluoroquinolone antibacterials×Mineral supplements. Macrominerals
Updated · Methodology
Mechanism
Magnesium is among the cations the label names outright. Magnesium-containing antacids and heavily buffered tablets fall under the same warning, so the interaction shows up both with the supplement and with the heartburn remedy the patient does not think of as a drug.
Symptoms
Slow or absent clinical response to the antibiotic, with no intolerance signs to point at the cause.
Management
Interval of 1–2 hours before or 4 hours after. Ask directly about antacids and evening magnesium: they rarely come up when the patient is asked what medication they take.
Check the full regimen, not just this pair
Opens the checker with these two drugs prefilled. Add the rest of the regimen and recompute additive risks.
Summary of a multi-drug list →
Medicine list: everything you take in one place →
Sources
- AEMPS: Ficha técnica Ciprofloxacino Cinfa 250 mg comprimidos recubiertos EFG (2024)– AEMPS, CIMA, nº registro 62768, sección 4.5
- NIH Office of Dietary Supplements: Magnesium – Health Professional Fact Sheet (2025)– NIH ODS, Magnesium, Interactions with Medications