Medical Editor: John P. Cunha, DO, FACOEP
Namenda XR (memantine hydrochloride) Extended Release is an NMDA receptor antagonist used to treat moderate to severe dementia of the Alzheimer's type. Common side effects of Namenda XR include:
- loss of appetite,
- tired feeling,
- weight loss or gain,
- swelling in your hands or feet,
- fast heart rate,
- easy bruising or bleeding,
- unusual weakness,
- joint pain,
- skin rash,
- redness or swelling of or around your eyes,
- urinating more than usual,
- abdominal pain,
- back pain,
- depression, and
- high or low blood pressure.
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. 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 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.
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.
Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
Stop using memantine and call your doctor at once if you have any of these serious side effects:
- cough, chest tightness, fever, trouble breathing;
- chest pain, fast heart rate;
- confusion, hallucinations;
- sudden numbness or weakness, especially on one side of the body;
- lack of coordination;
- fainting or seizure (convulsions);
- urinating less than usual or not at all;
- pale skin, easy bruising or bleeding, unusual weakness; or
- increased blood pressure (severe headache, blurred vision, trouble concentrating, chest pain, numbness, seizure).
Less serious side effects may include:
- nausea, vomiting, diarrhea, constipation, loss of appetite;
- dizziness, tired feeling;
- weight loss;
- 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; or
- urinating more than usual.
This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effect. You may report side effects to FDA at 1-800-FDA-1088.
Read the entire detailed patient monograph for Namenda XR (Memantine Hydrochloride Extended Release Capsules)
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
(n = 335) %
|NAMENDA XR 28mg
(n = 341) %
|Infections and infestations|
|Musculoskeletal and connective tissue disorders|
|Nervous system disorders|
|Renal and urinary disorders|
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.
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:
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.
Read the entire FDA prescribing information for Namenda XR (Memantine Hydrochloride Extended Release Capsules)