Last reviewed 2026-04-23 · How we verify

dextromethorphan+memantine

This combination blocks NMDA receptors (memantine) and inhibits reuptake of norepinephrine and serotonin (dextromethorphan) to modulate neuropathic pain and neurological symptoms.

This combination blocks NMDA receptors (memantine) and inhibits reuptake of norepinephrine and serotonin (dextromethorphan) to modulate neuropathic pain and neurological symptoms. Used for Neuropathic pain or neurological disorders (specific indication not publicly detailed).

At a glance

Mechanism of action

Memantine is a non-competitive NMDA receptor antagonist that reduces excitotoxicity and neuroinflammation. Dextromethorphan, a sigma-1 receptor agonist and NMDA antagonist, enhances neuroprotection and has analgesic properties. Together, they provide complementary NMDA antagonism and neuroprotective effects, potentially beneficial in neurodegenerative or neuropathic conditions.

Approved indications

• Neuropathic pain or neurological disorders (specific indication not publicly detailed)

Common side effects

• Dizziness
• Nausea
• Headache
• Cognitive effects

Key clinical trials

• Dextromethorphan, Memantine Monotherapy, or Combined Use of Dextromethorphan and Memantine in Amphetamine Addiction (PHASE2, PHASE3)
• Add-on Low Dose Dextromethorphan and Memantine in Patients With Amphetamine-type Stimulants Use Disorder (PHASE1, PHASE2)
• Study of NMDA Antagonists and Neuropathic Pain (PHASE2)
• Combination of Dextromethorphan and Memantine in Treating Bipolar Disorder (PHASE3)
• COMPARATIVE EFFECTIVENESS OF MCI and DEMENTIA TREATMENTS IN A COMMUNITY-BASED DEMENTIA PRACTICE
• Dextromethorphan Versus Placebo for Neuropathic Pain (PHASE2)

Primary sources

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