Memantine Use in Dementia: Evidence‑Based Recommendations

Indications and Efficacy

The U.S. Food and Drug Administration approves memantine for patients with moderate to severe Alzheimer’s disease, with randomized controlled trials demonstrating statistically significant improvements in cognition (ADAS‑Cog, Severe Impairment Battery), global function (CIBIC‑plus) and quality‑of‑life measures【1】【2】.
The Canadian Consensus Conference (2020) recommends memantine for moderate to severe Alzheimer’s disease as well as for Parkinson’s disease dementia, dementia with Lewy bodies, and vascular dementia, reflecting a consensus‑based guideline (moderate‑strength evidence)【3】【4】.

Withdrawal due to adverse events occurs in 9–12 % of patients receiving memantine compared with 7–13 % on placebo, indicating a low discontinuation rate (level I evidence)【1】【2】.
Dizziness is among the most frequently reported side‑effects of memantine (observed in clinical trials)【3】.
Agitation has also been reported as a memantine‑related adverse effect (comparable to placebo rates)【1】【2】.

Uncontrolled asthma is listed as an absolute contraindication to memantine therapy【2】.
Presence of left bundle‑branch block is another contraindication, based on safety data from clinical studies【5】.

Therapeutic benefit—either improvement or stabilization of symptoms—generally becomes apparent within three months of initiating memantine, as shown in trial follow‑up periods【5】.
The 2020 Canadian guidelines advise that memantine should be discontinued if no clinically meaningful benefit is observed at any point during treatment or if there is clinically meaningful worsening over six months【3】【4】.