Drug interactions
Memantine + Trimethoprim
Severity: Minor
Memantine and Trimethoprim: minor interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Trimethoprim is a cationic drug that inhibits OCT2 and MATE transporters, and may reduce memantine renal clearance, raising memantine levels. Memantine may in turn slightly compete with trimethoprim secretion. Effects are usually small except in renal impairment.
What this interaction means in plain words
Memantine and Trimethoprim have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Memantine belongs to Central Nervous System; Trimethoprim belongs to Anti Bacterial.
Why it happens
Competition for renal tubular cationic transport (OCT2/MATE).
What to do
Monitor for CNS effects such as confusion and dizziness during short antibiotic courses, especially in older patients or those with renal impairment.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Memantine and Trimethoprim, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 14 days on the web. No card needed.
Other interactions of Memantine
- Ketamine + Memantine Major
- Acetazolamide + Memantine Moderate
- Aluminum hydroxide + Memantine Moderate
- Amantadine + Memantine Moderate
- Dextromethorphan + Memantine Moderate
- Dofetilide + Memantine Moderate
Other interactions of Trimethoprim
Frequently asked questions
Can I take Memantine with Trimethoprim?
MediHelp rates the interaction as minor. Memantine and Trimethoprim have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Trimethoprim is a cationic drug that inhibits OCT2 and MATE transporters, and may reduce memantine renal clearance, raising memantine levels. Memantine may in turn slightly compete with trimethoprim secretion. Effects are usually small except in renal impairment.
How serious is the interaction between Memantine and Trimethoprim?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor for CNS effects such as confusion and dizziness during short antibiotic courses, especially in older patients or those with renal impairment.
What other medicines interact with Memantine?
MediHelp also lists interactions of Memantine with, for example, Ketamine, Acetazolamide, Aluminum hydroxide. The full list is on the Memantine page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
