Antacids (Tums, Maalox, Mylanta) and Ethambutol interaction
Antacids (Tums, Maalox, Mylanta) and Ethambutol: the Ethambutol 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 Ethambutol (ETHAMBUTOL HYDROCHLORIDE) label · effective 2025-08-22
It is recommended to avoid concurrent administration of ethambutol with aluminum hydroxide containing antacids for at least 4 hours following ethambutol administration.
Drug Interactions The results of a study of coadministration of ETHAMBUTOL HCl (50mg/kg) with an aluminum hydroxide containing antacid to 13 patients with tuberculosis showed a reduction of mean serum concentrations and urinary excretion of ethambutol of approximately 20% and 13%, respectively, suggesting that the oral absorption of ethambutol may be reduced…
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.