Reviewed on 8/19/2021

What Is Memantine and How Does It Work?

Memantine is a prescription drug used to treat moderate to severe confusion (dementia) related to Alzheimer's disease. It does not cure Alzheimer's disease, but it may improve memory, awareness, and the ability to perform daily functions. This medication works by blocking the action of a certain natural substance in the brain (glutamate) that is believed to be linked to symptoms of Alzheimer's disease.

  • Memantine is available under the following different brand names: Namenda XR, and Namenda.

What Are Dosages of Memantine?

Dosages of Memantine:


  • 5 mg
  • 10 mg

Capsule, extended-release

  • 7 mg
  • 14 mg
  • 21 mg
  • 28 mg

Oral solution

  • 2 mg/ml

Not indicated for pediatric use

Dosage Considerations – Should be Given as Follows:

Alzheimer-Type Dementia

  • Treatment of moderate-to-severe dementia
  • Tablet: 5 mg orally once daily initially; increased by increments of 5 mg/day each week; maintenance target dosage (more than 5 weeks): 20 mg/day orally divided every 12 hours
  • Extended-release capsule: 7 mg orally each day initially; may be increased by increments of 7 mg/day each week; maintenance target dose is 28 mg orally each day

Dosage Modifications

Renal impairment

  • Mild or moderate: No dosage adjustment is required
  • Severe: (creatinine clearance of 5-29 mL/min): Not to exceed 14 mg/day (extended-release) or 5 mg twice daily (prompt-release)

Hepatic impairment

  • Mild or moderate (Child Pugh A/B): No dosage adjustment required
  • Severe (Child Pugh C): Caution


  • May take with or without food
  • Consume entire capsule contents, do not divide the dose
  • Swallow the capsule whole or open and sprinkle on a spoonful of applesauce; do not chew or crush
  • Do not mix the oral solution with any other liquid
  • Missed dose: Do not double next dose, the next dose should be taken as scheduled; if missed for several days, dosing may need to be resumed at lower doses and re-titrated as described above

Mild-to-Moderate Vascular Dementia (off-label)

  • 5 mg (immediate-release) orally daily; titrate by 5 mg every 7 days to target dose 10 mg twice daily


Dementia, Alzheimer's Disease, and Aging Brains See Slideshow

What Are Side Effects Associated with Using Memantine?

Side effects of memantine include:

Postmarketing side effects of memantine reported include:

This document does not contain all possible side effects and others may occur. Check with your physician for additional information about side effects.

What Other Drugs Interact with Memantine?

If your doctor has directed you to use this medication, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first.

This information does not contain all possible interactions or adverse effects. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share this information with your doctor and pharmacist. Check with your health care professional or doctor for additional medical advice, or if you have health questions, concerns, or for more information about this medicine.


One of the first symptoms of Alzheimer's disease is __________________. See Answer

What Are Warnings and Precautions for Memantine?


  • This medication contains memantine
  • Do not take Namenda XR or Namenda if you are allergic to memantine or any ingredients contained in this drug
  • Keep out of reach of children
  • In case of overdose, get medical help or contact a Poison Control Center immediately


  • Hypersensitivity to product or components

Effects of Drug Abuse

  • No information available

Short-Term Effects

  • See "What Are Side Effects Associated with Using Memantine?"

Long-Term Effects

  • See "What Are Side Effects Associated with Using Memantine?"


  • Not evaluated in patients with a seizure disorder; seizures occurred in 0.2% of patients
  • Conditions that raise urine pH may decrease urinary elimination and increase plasma levels of memantine
  • Use caution in cardiovascular disease, seizure disorder, ophthalmic disease, liver and/or kidney impairment

Pregnancy and Lactation

  • Use of memantine during pregnancy may be acceptable
  • Either animal studies show no risk but human studies are not available or animal studies showed minor risks and human studies were done and showed no risk
  • It is unknown whether memantine is excreted into breast milk; use with caution if breastfeeding
Medscape. Memantine.
RxList. Namenda.

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