Dextromethorphan and Memantine Interaction
Drug interaction information between Dextromethorphan and Memantine.
Dextromethorphan and Memantine have a documented moderate interaction in FDA labeling.
FDA drug labeling documents a moderate-severity interaction between Dextromethorphan and Memantine. This page displays the available source-record category and label text. The category is not an individual risk estimate or medication-combination direction.
How They Interact
Both of these drugs affect the same receptors in the brain, and using them together has not been well studied. This could cause unknown side effects or change how the medications work.
FDA Label Information
7.2 Use with Other N-methyl-D-aspartate (NMDA) Antagonists The combined use of memantine hydrochloride with other NMDA antagonists (amantadine, ketamine, and dextromethorphan) has not been systematically evaluated and such use should be approached with caution.
Dextromethorphan Also Interacts With
- Safinamide major
- Rasagiline moderate
- Tranylcypromine moderate
- Abiraterone minor
- Aripiprazole minor
Frequently Asked Questions
What SPL severity band is on file for Dextromethorphan + Memantine?
Compiled FDA labeling labels this pair moderate. That is a source-record field, not an individual medication-combination decision.
Which drug in this pair has the larger labeled-interaction portfolio?
Dextromethorphan has 15 labeled pairs on file vs Memantine's 2. In the moderate band specifically: Dextromethorphan has 3 (also Rasagiline, Tranylcypromine); Memantine has 1.
What mechanism field is on file for Dextromethorphan and Memantine?
Both of these drugs affect the same receptors in the brain, and using them together has not been well studied. This could cause unknown side effects or change how the medications work.
Dextromethorphan carries more major-labeled pairs than Memantine
SPL source-record counts only. This page's band is moderate · classes on file: Dextromethorphan (Antitussive); Memantine (NMDA Receptor Antagonist).
Dextromethorphan has 1 major-labeled pair vs Memantine's 0. This page itself is in the moderate band, not the major band.
1 major · 3 moderate · 11 minor · 15 total
- Other moderate peers for Dextromethorphan
- Rasagiline
- Tranylcypromine
0 major · 1 moderate · 1 minor · 2 total
Memantine has no other moderate-band peer in this dataset besides Dextromethorphan.
Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. This registry does not provide individual medication-combination directions.
Read our methodology - how this data is sourced, computed, and verified.