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NAMENDA XR® (memantine hydrochloride) extended-release capsules are approved for the treatment of moderate to severe Alzheimer's disease. NAMENDA XR is available by prescription only.

NAMENDA XR® Side Effects

The most common side effects associated with NAMENDA XR® (memantine hydrochloride) treatment are headache, diarrhea, and dizziness. This is not a complete list of side effects.

Most Common Side Effects of NAMENDA XR

The most common side effects occurring in a clinical trial in at least 2% of patients treated with NAMENDA XR and at a greater rate than in patients given placebo (a sugar pill) are listed in the chart below. Headache, diarrhea, and dizziness occurred at a rate of at least 5% in NAMENDA XR-treated patients and at a greater rate than in the placebo group.

Side Effect NAMENDA XR 28 mg+AChEI
(n=341)
%
Placebo+AChEI
(n=335)
%
Gastrointestinal disorders    
Diarrhea 5 4
Constipation 3 1
Abdominal Pain 2 1
Vomiting 2 1
Infections and infestations    
Influenza 4 3
Investigations    
Weight, increased 3 1
Musculoskeletal and connective tissue disorders    
Back pain 3 1
Nervous system disorders    
Headache 6 5
Dizziness 5 1
Somnolence* 3 1
Psychiatric disorders    
Anxiety 4 3
Depression 3 1
Aggression 2 1
Renal and urinary disorders    
Urinary incontinence 2 1
Vascular disorders    
Hypertension 4 2
Hypotension 2 1

*Drowsiness

Discontinuation due to side effects was 10% for the NAMENDA XR 28 mg+AChEI treatment group and 6.3% for the placebo+AChEI treatment group. The most common side effect that led to treatment discontinuation in this study was dizziness, at a rate of 1.5% in the NAMENDA XR-treated group.

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Important Risk Information

Who should NOT take NAMENDA XR?

NAMENDA XR should not be taken by anyone who is allergic (hypersensitive) to memantine, the active substance in NAMENDA XR, or who has had a bad reaction to NAMENDA XR or any of its ingredients.

What should be discussed with the healthcare provider before taking NAMENDA XR?

Before starting NAMENDA XR, talk to the healthcare provider about all of the patient's past and present medical conditions, including:

  • Seizure disorders
  • Difficulty passing urine
  • Liver or kidney problems

If the patient is taking other medications (including those without a prescription), ask the healthcare provider if NAMENDA XR is right for the patient.

  • Certain medications, changes in diet, or medical conditions may affect the amount of NAMENDA XR in the body and possibly increase side effects.

What are the possible side effects of NAMENDA XR?

The most common side effects associated with NAMENDA XR treatment are headache, diarrhea, and dizziness. This is not a complete list of side effects.

Please see full Prescribing Information, including Patient Information.

WebMD does not endorse any specific product, service, or treatment.

Important Risk Information

Who should NOT take NAMENDA XR?

NAMENDA XR should not be taken by anyone who is allergic (hypersensitive) to memantine, the active substance in NAMENDA XR, or who has had a bad reaction to NAMENDA XR or any of its ingredients.

What should be discussed with the healthcare provider before taking NAMENDA XR?

Before starting NAMENDA XR, talk to the healthcare provider about all of the patient's past and present medical conditions, including:

  • Seizure disorders
  • Difficulty passing urine
  • Liver or kidney problems

If the patient is taking other medications (including those without a prescription), ask the healthcare provider if NAMENDA XR is right for the patient.

  • Certain medications, changes in diet, or medical conditions may affect the amount of NAMENDA XR in the body and possibly increase side effects.

What are the possible side effects of NAMENDA XR?

The most common side effects associated with NAMENDA XR treatment are headache, diarrhea, and dizziness. This is not a complete list of side effects.

Please see full Prescribing Information, including Patient Information.

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