The short answer
Some magnesium-containing antacids can reduce oral digoxin exposure. Have the pharmacist check the exact product and timing; the evidence does not apply equally to every nutrient preparation.
What this answer covers
Oral magnesium-containing antacids with oral digoxin tablets. Elemental nutrient categories, foods, other salts and injected digoxin are separate.
- Supplement or preparation
- Magnesium
- Medication ingredient
- digoxin
What the original studies found
A small study found reduced urinary recovery of digoxin with aluminum hydroxide, magnesium hydroxide and magnesium trisilicate, supporting reduced absorption. Another study found lower peaks but no significant change in24-hour exposure, with differences between tablets and capsules. The findings are not identical across formulations.
The ingredient and dosage form matter
These studies concern antacid compounds taken with oral digoxin. They do not establish the same effect for ordinary food intake, every magnesium or aluminum product, or intravenous digoxin. Bring the exact antacid or supplement label, dose and usual schedule to the pharmacist.
Ask for a product-specific schedule
The digoxin label lists antacids among products that can lower concentrations and advises concentration monitoring when interacting treatment changes. The inspected studies do not establish a universal two-hour rule for every magnesium preparation. Ask the pharmacist about the specific product rather than choosing a gap or dose change yourself.
Know when to seek assessment
Contact your clinician about new nausea, loss of appetite, visual changes, marked weakness or an unusually slow or irregular pulse. These may have several causes, including digoxin toxicity. Blood results must be interpreted with symptoms, kidney function and electrolytes; do not adjust digoxin yourself.
Evidence and practical considerations
Absorption & effectiveness
Defined aluminum or magnesium antacids can interfere with oral digoxin bioavailability, with formulation-dependent results.
- Exact scope
- Oral magnesium-containing antacids with oral digoxin tablets. Elemental nutrient categories, foods, other salts and injected digoxin are separate. with Exact digoxin RxCUI3407 IN, confirmed by current RxNorm. Oral125/250microgram tablets; oral absorption evidence is not transferred to IV digoxin. Digoxin is distinct from digitoxin.
- Medication form and route
- Oral
What remains uncertain
- Small studies and different exposure measures; conditional evidence for named antacid salts only. Fixed two-hour spacing for all magnesium is not established.
Factors that may matter: Exact preparation and dose; Kidney function; Baseline electrolyte status; Other medicines.
Read the supporting source summaries
Source 1: Current prescribing information
dailymed.nlm.nih.gov · Source check Sep 10, 2026
Population: Patients prescribed oral digoxin tablets.
Antacids and St.John’s wort can lower concentrations. Hypokalemia, hypomagnesemia and hypercalcemia predispose to toxicity; assess electrolytes/renal function. Some substances interfere with assays without proving increased drug exposure.
How this applies: Exact medication label. Exact digoxin RxCUI3407 IN, confirmed by current RxNorm. Oral125/250microgram tablets; oral absorption evidence is not transferred to IV digoxin. Digoxin is distinct from digitoxin.
No universal nutrient spacing or vitaminD replacement need. Clinical state, assay method and formulation must be considered.
Source 2: Original clinical research
pubmed.ncbi.nlm.nih.gov · Source check Sep 10, 2026
Population: Ten healthy volunteers in a Latin-square single-dose study.
Six-day urinary recovery fell significantly with the antacids, supporting reduced oral bioavailability.
How this applies: Applicability is limited to the stated exact medication, preparation and endpoint; other-drug evidence is indirect.
Abstract-only old formulations; urinary recovery is an exposure proxy, not loss of clinical disease control. Exact antacid compounds, not elemental nutrients or all salts.
Source 3: Original clinical research
pubmed.ncbi.nlm.nih.gov · Source check Sep 10, 2026
Population: Twelve healthy fasting volunteers in a six-way crossover.
Peaks were reduced but24-hour AUC was not significantly altered; urinary recovery tended lower for tablets, not capsules.
How this applies: Applicability is limited to the stated exact medication, preparation and endpoint; other-drug evidence is indirect.
Abstract-only; short sampling and formulation differences matter. Null AUC does not refute every antacid interaction.
Source 4: Medication terminology
rxnav.nlm.nih.gov · Source check Sep 10, 2026
Population: Terminology.
digoxin is IN.
How this applies: Exact ingredient.
Not clinical evidence.
Research assessment: · Open full citations ↗
Review and change history
- Publication status
- Published research summary
- Clinical review
- Not yet recorded
| Date | Update |
|---|---|
| Article prepared | |
| Sources checked and article drafted. | |
| Research summary published |
Article revision: bce31cd389ed854c
This guide brings together the evidence records used by our interaction checker. Each finding retains its own preparation limits, research date, and source summaries.
Full citations require verification. Reading this answer and the source summaries does not.
Taking other supplements or medications?
Use the checker to explore your other combinations. Ask a pharmacist to review the exact products, amounts and medical conditions in your complete list.
Open the interaction checkerInformation, not medical advice. Do not change prescribed treatment based on this guide.