Drug reference

Memantine

Antiepileptic · Dementia Treatment

Also known as Memantine hydrochloride

AntiepilepticDementia Treatment

CDSCO approvedSchedule H

EXCRETION

—

not curated

INTERACTIONS

—

none in our sources

PREGNANCY

Avoid unless essential; no human data

FDA category + note

Mechanism

Memantine is a moderate-affinity, uncompetitive antagonist of the NMDA glutamate receptor that blocks the receptor ion channel in a voltage-dependent manner, preferentially under conditions of sustained low-level activation (excitotoxicity) while preserving normal phasic synaptic transmission. By reducing glutamate-mediated excitotoxicity that contributes to neuronal damage in Alzheimer disease, it provides modest symptomatic benefit in moderate-to-severe dementia. It does not affect cholinergic transmission and can be combined with cholinesterase inhibitors.

Indications

Moderate Alzheimer D disease (as an alternative if acetylcholinesterase inhibitors are not tolerated or contra-indicated)Severe Alzheimer D diseaseModerate or severe Alzheimer D disease (as an add-on to an acetylcholinesterase inhibitor if the patient is already receiving one)Dementia with Lewy bodies (off-label, as an alternative if acetylcholinesterase inhibitors are contra-indicated or not tolerated)Vascular dementia (off-label, only if suspected co-morbid Alzheimer D disease, Parkinson D disease dementia, or dementia with Lewy bodies)Moderate-to-severe stages of dementia due to ADmoderate to severe ADdecreasing caregiver burden

Dosing

Adult: Alzheimer's disease (moderate-severe): initially 5 mg OD, increase by 5 mg weekly. Maintenance: 20 mg OD.
Renal adjustment: eGFR 5-29: reduce to 10 mg daily. eGFR <5: avoid.
Hepatic adjustment: Caution in severe hepatic impairment
Geriatric: Follow standard titration; monitor for CNS effects
Max dose: 20 mg daily