Sometimes. It depends on the antibiotic, and for a few common ones the answer is a firm no.
Calcium carbonate (Tums) grabs onto certain antibiotics in your stomach so your body never absorbs the full dose. For ciprofloxacin, MedlinePlus directs you to take it at least 2 hours before or 6 hours after antacids containing calcium, aluminum, or magnesium, and the same window covers calcium, iron, and zinc supplements. For doxycycline, antacids and calcium supplements go 1 to 2 hours before or after the dose, iron 3 hours apart. Antibiotics like amoxicillin, azithromycin, and cephalexin do not have this problem. Heartburn itself is common on antibiotics, so if you need relief, spacing doses or asking about an alternative antacid is usually all it takes.
Can I take Tums with antibiotics? What to do
Common questions
Can I take Tums with antibiotics?
It depends which antibiotic you are on. Calcium, the active ingredient in Tums, binds some antibiotics in the gut and stops them being absorbed, which can make the treatment fail. The two big groups where this matters: fluoroquinolones like ciprofloxacin, where MedlinePlus says to take ciprofloxacin at least 2 hours before or 6 hours after antacids containing calcium, aluminum, or magnesium; and tetracyclines like doxycycline, where antacids and calcium supplements should be taken 1 to 2 hours before or after the dose, and iron products 3 hours apart. Many other common antibiotics, including amoxicillin and azithromycin, are not affected by Tums. The safe default: if your antibiotic label or pharmacist warned you about antacids or dairy, keep Tums at least 2 hours away. If nothing was said, occasional Tums is generally fine. When in doubt, ask the pharmacist who filled the prescription.