Antacids (Tums, Maalox, Mylanta) and Fexofenadine interaction
Antacids (Tums, Maalox, Mylanta) and Fexofenadine: the Fexofenadine prescribing label flag 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 Fexofenadine (Childrens Allegra Allergy) label · effective 2026-01-13
When using this product do not take more than directed do not take at the same time as aluminum or magnesium antacids do not take with fruit juices (see Directions) Stop use and ask a doctor if an allergic reaction to this product occurs.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
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.