Namenda XR Side Effects Center

Last updated on RxList: 4/20/2022
Namenda XR Side Effects Center

What Is Namenda XR?

Namenda XR (memantine hydrochloride) Extended Release is an NMDA receptor antagonist used to treat moderate to severe dementia of the Alzheimer's type.

What Are Side Effects of Namenda XR?

Common side effects of Namenda XR include:

  • nausea,
  • vomiting,
  • diarrhea,
  • constipation,
  • loss of appetite,
  • dizziness,
  • tired feeling,
  • weight loss or gain,
  • swelling in your hands or feet,
  • fast heart rate,
  • easy bruising or bleeding,
  • unusual weakness,
  • joint pain,
  • anxiety,
  • aggression,
  • skin rash,
  • redness or swelling of or around your eyes,
  • urinating more than usual,
  • abdominal pain,
  • influenza,
  • back pain,
  • headache,
  • drowsiness,
  • anxiety,
  • depression, and
  • high or low blood pressure.

Dosage for Namenda XR

The recommended starting dose of Namenda XR is 7 mg once daily. The dose should be increased in 7 mg increments to a target maximum dose of 28 mg once daily. The minimum recommended interval between dose increases is one week, and only if the previous dose has been well tolerated.

What Drugs, Substances, or Supplements Interact with Namenda XR?

Namenda XR may interact with cimetidine, nicotine, ranitidine, quinidine, sodium bicarbonate, antiviral medications, cold or cough medicine containing dextromethorphan, diuretics, medicines to treat glaucoma, or oral diabetes medicines containing metformin. Tell your doctor all medications and supplements you use.

Namenda XR During Pregnancy or Breastfeeding

Namenda XR is not expected to be harmful to a fetus. Tell your doctor if you are pregnant or plan to become pregnant during treatment. It is unknown if this drug passes into breast milk. Consult your doctor before breastfeeding.

Additional Information

Our Namenda XR (memantine hydrochloride) Extended Release Capsules Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


One of the first symptoms of Alzheimer's disease is __________________. See Answer
Namenda XR Consumer Information

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Get emergency medical help if you have signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have:

  • severe headache, blurred vision, pounding in your neck or ears;
  • seizure (convulsions); or
  • unusual changes in mood or behavior.

Common side effects may include:

  • diarrhea;
  • dizziness; or
  • headache.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


Dementia, Alzheimer's Disease, and Aging Brains See Slideshow
Namenda XR Professional Information


Clinical Trials Experience

NAMENDA XR was evaluated in a double-blind placebo-controlled trial in which a total of 676 patients with moderate to severe dementia of the Alzheimer's type (341 patients on NAMENDA XR 28 mg/day and 335 patients on placebo) were treated for up to 24 weeks.

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

Adverse Reactions Leading To Discontinuation

In the placebo-controlled clinical trial of NAMENDA XR, the proportion of patients in the NAMENDA XR group and the placebo group who discontinued treatment due to adverse reactions was 10% and 6%, respectively. The most common adverse reaction that led to treatment discontinuation in the NAMENDA XR group was dizziness, at a rate of 1.5%.

Most Common Adverse Reactions

The most commonly observed adverse reactions seen in patients administered NAMENDA XR in the controlled clinical trial, defined as those occurring at a frequency of at least 5% in the NAMENDA XR group and at a frequency higher than placebo, were headache, diarrhea and dizziness.

Table 1 lists adverse reactions that were observed at an incidence of ≥ 2% in the NAMENDA XR group and occurred at a rate greater than placebo.

Table 1: Adverse Reactions Observed with a Frequency of ≥ 2% in the NAMENDA XR Group and at a Rate Greater than Placebo

Adverse Reaction Placebo
(n=335) %
(n=341) %
Gastrointestinal Disorders
Diarrhea 4 5
Constipation 1 3
Abdominal pain 1 2
Vomiting 1 2
Infections and Infestations
Influenza 3 4
Weight, increased 1 3
Musculoskeletal and Connective Tissue Disorders
Back pain 1 3
Nervous System Disorders
Headache 5 6
Dizziness 1 5
Somnolence 1 3
Psychiatric Disorders
Anxiety 3 4
Depression 1 3
Aggression 1 2
Renal and Urinary Disorders
Urinary incontinence 1 2
Vascular Disorders
Hypertension 2 4
Hypotension 1 2


Memantine has not been systematically evaluated in patients with a seizure disorder. In clinical trials of memantine, seizures occurred in 0.3% of patients treated with memantine and 0.6% of patients treated with placebo.

Postmarketing Experience

The following adverse reactions have been identified during post-approval use of memantine. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. These reactions include:

Blood and Lymphatic System Disorders: agranulocytosis, leukopenia (including neutropenia), pancytopenia, thrombocytopenia, thrombotic thrombocytopenic purpura.

Cardiac Disorders: cardiac failure congestive.

Gastrointestinal Disorders: pancreatitis.

Hepatobiliary Disorders: hepatitis.

Psychiatric Disorders: suicidal ideation.

Renal and Urinary Disorders: acute renal failure (including increased creatinine and renal insufficiency).

Skin Disorders: Stevens Johnson syndrome.


Drugs That Make Urine Alkaline

The clearance of memantine was reduced by about 80% under alkaline urine conditions at pH 8. Therefore, alterations of urine pH towards the alkaline condition may lead to an accumulation of the drug with a possible increase in adverse effects. Urine pH is altered by diet, drugs (e.g. carbonic anhydrase inhibitors, sodium bicarbonate) and clinical state of the patient (e.g. renal tubular acidosis or severe infections of the urinary tract). Hence, memantine should be used with caution under these conditions.

Use With Other N-methyl-D-aspartate (NMDA) Antagonists

The combined use of NAMENDA XR with other NMDA antagonists (amantadine, ketamine, and dextromethorphan) has not been systematically evaluated and such use should be approached with caution.

Read the entire FDA prescribing information for Namenda XR (Memantine Hydrochloride Extended Release Capsules)

© Namenda XR Patient Information is supplied by Cerner Multum, Inc. and Namenda XR Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.

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