Antacids (Tums, Maalox, Mylanta) and Bismuth subcitrate, metronidazole, and tetracycline interaction
Antacids (Tums, Maalox, Mylanta) and Bismuth subcitrate, metronidazole, and tetracycline: the Bismuth subcitrate, metronidazole, and tetracycline prescribing label flags this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Bismuth subcitrate, metronidazole, and tetracycline (Bismuth Subcitrate Potassium, Metronidazole and Tetracycline Hydrochloride) label · effective 2026-04-13
Antacids, Multivitamins or Dairy Products: Decreased absorption of Bismuth Subcitrate Potassium, Metronidazole and Tetracycline Hydrochloride Capsules; do not take concomitantly.
Antacids, Multivitamins, or Dairy Products The absorption of bismuth subcitrate potassium, metronidazole and tetracycline hydrochloride may be reduced if administered with antacids containing aluminium, calcium, or magnesium; preparations containing iron, zinc, or sodium bicarbonate; or milk or dairy products due to the interaction between these products and…
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Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.