PharmaceuticalNootropicNMDA antagonistAdamantaneAnti-dementia

Memantine

Also known as Namenda · Ebixa · Axura · 1-amino-3,5-dimethyladamantane

Written by enwyReviewed 5 Aug 20262 sources0 comments

Memantine is a low-to-moderate affinity, voltage-dependent, uncompetitive NMDA receptor antagonist approved for moderate-to-severe Alzheimer's disease. Its fast off-rate lets it dampen pathological glutamate excitotoxicity while largely preserving normal synaptic transmission, so it is essentially non-psychoactive at therapeutic doses.

01 Overview

Memantine (brand Namenda, Ebixa) has been used clinically since the 1980s in Europe and was approved by the FDA in 2003. It is well tolerated and lacks the strong dissociative profile of ketamine or PCP because of its rapid channel-blocking kinetics and moderate affinity, which allow it to leave the channel during normal high-frequency signalling.

Beyond dementia it is studied off-label for neuropathic pain, and it is sometimes used to attenuate tolerance to other drugs. Recreational misuse is uncommon and generally unrewarding; very high doses can produce dissociation and confusion but with an unpleasant, delayed, long-lasting course.

02 Mechanism

Uncompetitive, voltage-dependent open-channel blocker of the NMDA receptor with a fast off-rate; preferentially blocks excessive tonic glutamate activity implicated in excitotoxicity.

03 Dosing

Tier	Dose	Route	Notes
Alzheimer's maintenance	10–20 mg/day	Oral	Titrated from 5 mg/day in weekly steps; standard dementia dose.

04 Effects

Effect	Magnitude	Evidence
Cognitive stabilisation in dementiaSlows functional and cognitive decline in moderate-to-severe Alzheimer's disease.	modest	Clinical
NMDA tolerance/pain modulationStudied for reducing opioid tolerance and easing neuropathic pain, with mixed results.	variable	Observational

05 Side effects

Effect	Severity	Frequency	Evidence	Countermeasures
Dizziness and confusionDizziness, headache and confusion, especially during titration.	Mild	Common	Clinical
Agitation or hallucinations at high doseSupratherapeutic or overdose amounts can cause a prolonged, unpleasant dissociative/confusional state.	Moderate	Rare, dose-related	Observational

06 Legal status

United States

Rx only, not scheduled

Approved for Alzheimer's disease. · as of Jan 2026

United Kingdom

POM

Licensed for moderate-to-severe Alzheimer's. · as of Jan 2026

07 References

Memantine in Moderate-to-Severe Alzheimer's DiseaseN Engl J Med, 2003

Memantine: pharmacology and clinical useCNS Drug Reviews, 2003

08 Discussion0 comments

Create account

Discussion is moderated. No sourcing, vendor names or price talk — those comments are removed, and repeat posts are banned.

This page is reference information, not medical advice. Doses and protocols are documented as they appear in the clinical literature and in practice — describing them is not a recommendation to use them. Countermeasures listed here are not a substitute for a physician. Legal status varies by jurisdiction and changes.