Drug Interaction Report

Memantine and Sodium Bicarbonate: Interaction Details

A pharmacist-reviewed analysis of the Memantine and Sodium Bicarbonate interaction: the documented clinical effects, severity rating, onset, mechanism, and management considerations, with cited references throughout.

AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature

Memantine

Namenda Namenda XR® Namenda® Namenda® Titration Pak Namzaric®(as a combination product containing Donepezil, Memantine)
+

Sodium Bicarbonate

Alka-Seltzer® Heartburn Desempacho Neut brand of sodium bicarbonate
Dr. Brian Staiger, PharmD, BCPS
Medically reviewed by
Dr. Brian Staiger, PharmD, BCPS
Updated Aug 8, 2026
Editorial policy · Data sources
LinkedIn
Interaction severity
Major
Potentially serious — often needs a change or close monitoring.
How we grade severity & evidence

Severity levels

  • Contraindicated: These should generally not be used together.
  • Major: Potentially serious — often needs a change or close monitoring.
  • Moderate: Can be significant — usually manageable with monitoring.
  • Minor: Usually limited clinical impact.

Evidence grades

  • Established: Well documented — supported by controlled studies or strong clinical data.
  • Probable: Good supporting evidence, though not definitively proven.
  • Suspected: Some evidence suggests this interaction, but it is not well established.
  • Possible: Limited or conflicting evidence; the interaction may occur.
  • Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.

Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.

Of 24 documented Memantine interactions, 16 are rated major — including this one.
Worried about symptoms right now? Contact your pharmacist or prescriber, or call Poison Control at 1-800-222-1222 (US). Call 911 for an emergency.
Onset
unspecified
Evidence
theoretical
Severity
Major

What happens

Reduced renal clearance of memantine

Interaction Deep Dive

Reduction of renal elimination of memantine occurs with drugs that alkalinize the urine, such as sodium bicarbonate. Under alkaline urine conditions at pH 8, memantine clearance was reduced by about 80%. The accumulation of memantine may result in increased adverse effects312.

Why it happens (mechanism)

Urine alkalinization by sodium bicarbonate

Common questions

Can I take Memantine and Sodium Bicarbonate together?

Reduced renal clearance of memantine Always confirm with your pharmacist or prescriber before making any change.

How serious is the Memantine and Sodium Bicarbonate interaction?

It is rated major. Potentially serious — often needs a change or close monitoring.

How quickly could this interaction happen?

The documented onset is "unspecified". The timing of this interaction is not well characterized.

How strong is the evidence for this interaction?

The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.

Questions for your pharmacist

  • Does my dose of Memantine or Sodium Bicarbonate need adjusting while I take them together?
  • What symptoms should prompt me to call you or my prescriber right away?
  • Does the timing of my doses matter for this combination?
  • Is there a safer alternative to one of these medications for me?

References (3)

  1. Product Information: Namenda(R) oral tablets, solution, memantine hydrochloride oral tablets, solution. Forest Pharmaceuticals Inc, St Louis, MO, 2007. DailyMed
  2. Product Information: NAMENDA XR(R) extended release oral capsules, memantine hydrochloride extended release oral capsules. Forest Pharmaceuticals, Inc, New York, NY, 2010.
  3. Product Information: NAMZARIC oral capsules, memantine HCl extended-release donepezil HCl oral capsules. Forest Laboratories LLC (per manufacturer), St. Louis, MO, 2014. DailyMed
Was this write-up helpful?
Memantine

Keep reading about Memantine

All Memantine interactions (24) Memantine drug information
Also serious with: Brinzolamide Bupropion Dextromethorphan Methotrexate Injection
Sodium Bicarbonate

Keep reading about Sodium Bicarbonate

All Sodium Bicarbonate interactions (26) Sodium Bicarbonate drug information
Also serious with: Gefitinib Neratinib Mefenamic Acid Octreotide
Beyond drug–drug

These medications also interact with supplements

Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:

Memantine + Activated Charcoal Threonine Coffee Charcoal European Mandrake Glucomannan Guar Gum Gum Arabic Slippery Elm + 10 more

major · moderate · minor — check everything you take with our drug–supplement interaction checker.

Check another combination

Our instant two-drug interaction checker is almost here.

Coming soon

The instant two-drug checker is on its way.

In the meantime, browse the directory below to look up any drug and see its documented interactions.

Still have questions about this combination?

Every question gets a real answer from a licensed pharmacist — free, and usually within a day.

Ask the pharmacist
This information is for education, not a substitute for professional medical advice. Do not start, stop, or change any medication without talking to your pharmacist or prescriber.