Memantine
2 medicines
Memantine is an NMDA-receptor antagonist for moderate-to-severe Alzheimer's disease. It eases symptoms but does not stop or reverse the underlying disease, and the dose must be lowered in severe kidney impairment.
Key facts
- Memantine (sold as Namenda) is an NMDA-receptor antagonist used for moderate-to-severe Alzheimer's disease.
- The dose is usually started low and increased gradually over several weeks to limit side effects.
- It eases symptoms such as memory and daily-function decline but does not stop, cure or reverse the underlying disease.
- Because memantine is cleared mainly by the kidneys, your prescriber will use a lower dose if you have severe kidney impairment.
What memantine treats
Memantine treats moderate-to-severe Alzheimer's disease. It is sometimes added to a cholinesterase inhibitor, such as donepezil, for combined effect. It is not approved for mild Alzheimer's disease or for other forms of dementia, such as vascular dementia. Memantine comes as immediate-release tablets, usually taken twice daily, or extended-release capsules taken once daily; the two forms are dosed differently, so switch between them only on your prescriber's advice.
How memantine works
Memantine partially blocks NMDA glutamate receptors in the brain, receptors that become overactive in Alzheimer's disease and contribute to nerve-cell damage. By moderating, rather than eliminating, this signaling, it may help preserve some nerve-cell function and slow the worsening of symptoms.
Before you take it
- Tell your prescriber about severe kidney disease, seizures, or urinary tract infections and other conditions that raise urine pH, since these can raise memantine levels.
- Combining memantine with other NMDA-receptor blocking drugs, such as amantadine or ketamine, is not recommended.
- Confusion, dizziness or drowsiness can increase fall risk, especially in older adults living alone.
Side effects
Common effects include dizziness, headache, confusion, constipation and drowsiness.
Stop and seek urgent medical care for:
- Signs of a serious allergic reaction: rash, swelling, or difficulty breathing.
- New hallucinations or severe confusion.
- A seizure.
Safety essentials
- Memantine dosing must be reduced in severe kidney impairment, since the kidneys clear the drug; report any change in kidney function to your prescriber.
- It treats symptoms only and does not slow the underlying brain disease, so expectations about what it can achieve should stay realistic.
- Report new or worsening confusion, hallucinations or seizures to your prescriber promptly.
This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.