"Today, the U.S. Food and Drug Administration issued a proposal designed to assist companies developing new treatments for patients in the early stages of Alzheimer's disease, before the onset of noticeable (overt) dementia.
Namenda XR Side Effects Center
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 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.
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.
What is Patient Information in Detail?
Easy-to-read and understand detailed drug information and pill images for the patient or caregiver from Cerner Multum.
Namenda XR in Detail - Patient Information: Side Effects
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) »
What is Prescribing information?
The FDA package insert formatted in easy-to-find categories for health professionals and clinicians.
Namenda XR FDA Prescribing Information: Side Effects
Clinical Trial Data Sources
NAMENDA XR was evaluated in a double-blind placebo-controlled trial treating a total of 676 patients with moderate to severe dementia of the Alzheimer's type (341 patients treated with NAMENDA XR 28 mg/day dose and 335 patients treated with placebo) for a treatment period 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 [See Clinical Studies], which treated a total of 676 patients, the proportion of patients in the NAMENDA XR 28 mg/day dose and placebo groups who discontinued treatment due to adverse events were 10.0% and 6.3%, respectively. The most common adverse reaction in the NAMENDA XR treated group that led to treatment discontinuation in this study 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 higher frequency than placebo were headache, diarrhea and dizziness.
Table 1 lists treatment-emergent adverse reactions that were observed at an incidence of ≥ 2% in the NAMENDA XR treated group and occurred at a rate greater than placebo.
Table 1: Adverse reactions observed with a frequency
of ≥ 2% and occurring with 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|
Vital Sign Changes
NAMENDA XR and placebo groups were compared with respect to (1) mean change from baseline in vital signs (pulse, systolic blood pressure, diastolic blood pressure, and weight) and (2) the incidence of patients meeting criteria for potentially clinically significant changes from baseline in these variables. There were no clinically important changes in vital signs in patients treated with NAMENDA XR. A comparison of supine and standing vital sign measures for NAMENDA XR and placebo in Alzheimer's patients indicated that NAMENDA XR treatment is not associated with orthostatic changes.
NAMENDA XR and placebo groups were compared with respect to (1) mean change from baseline in various serum chemistry, hematology, and urinalysis variables and (2) the incidence of patients meeting criteria for potentially clinically significant changes from baseline in these variables. These analyses revealed no clinically important changes in laboratory test parameters associated with NAMENDA XR treatment.
NAMENDA XR and placebo groups were compared with respect to (1) mean change from baseline in various ECG parameters and (2) the incidence of patients meeting criteria for potentially clinically significant changes from baseline in these variables. These analyses revealed no clinically important changes in ECG parameters associated with NAMENDA XR treatment.
Other Adverse Reactions Observed During Clinical Trials Of NAMENDA XR
Following is a list of treatment-emergent adverse reactions reported from 750 patients treated with NAMENDA XR for periods up to 52 weeks in double-blind or open-label clinical trials. The listing does not include those events already listed in Table 1, those events for which a drug cause was remote, those events for which descriptive terms were so lacking in specificity as to be uninformative, and those events reported only once which did not have a substantial probability of being immediately life threatening. Events are categorized by body system.
Blood and Lymphatic System Disorders: anemia.
Gastrointestinal Disorders: fecal incontinence, nausea.
Injury, Poisoning and Procedural Complications: fall.
Investigations: weight decreased.
Musculoskeletal and Connective Tissue Disorders: arthralgia, pain in extremity.
Respiratory, Thoracic and Mediastinal Disorders: cough, dyspnea.
Memantine Immediate Release Clinical Trial And Post Marketing Spontaneous Reports
The following additional adverse reactions have been identified from previous worldwide experience with memantine (immediate release) use. These adverse reactions have been chosen for inclusion because of a combination of seriousness, frequency of reporting, or potential causal connection to memantine and have not been listed elsewhere in labeling. However, because some of these adverse reactions were reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship between their occurrence and the administration of memantine. These events include:
Endocrine Disorders: inappropriate antidiuretic hormone secretion.
General disorders and administration site conditions: malaise, sudden death.
Hepatobiliary Disorders: hepatitis (including abnormal hepatic function test, cytolytic and cholestatic hepatitis), hepatic failure.
Infections and infestations: sepsis.
Metabolism and Nutrition Disorders: hypoglycaemia, hyponatraemia.
Nervous System Disorders: convulsions (including grand mal), cerebrovascular accident, dyskinesia, extrapyramidal disorder, hypertonia, loss of consciousness, neuroleptic malignant syndrome, Parkinsonism, tardive dyskinesia, transient ischemic attack.
Psychiatric Disorders: hallucinations (both visual and auditory), restlessness, suicidal ideation.
Renal and Urinary Disorders: acute renal failure (including abnormal renal function test), urinary retention.
Skin Disorders: rash, Stevens Johnson syndrome.
The following adverse events have been reported to be temporally associated with memantine treatment and are not described elsewhere in the product labeling: aspiration pneumonia, bone fracture, carpal tunnel syndrome, cerebral infarction, chest pain, cholelithiasis, claudication, depressed level of consciousness (including rare reports of coma), dysphagia, encephalopathy, gastritis, gastroesophageal reflux, intracranial hemorrhage, hyperglycemia, hyperlipidemia, ileus, impotence, lethargy, myoclonus, supraventricular tachycardia, and tachycardia. However, there is again no evidence that any of these additional adverse events are caused by memantine.
Read the entire FDA prescribing information for Namenda XR (Memantine Hydrochloride Extended Release Capsules) »
Additional Namenda XR Information
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
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