Namenda XR 7mg Capsules
It is used to treat dementia in people with Alzheimer's disease.
Drug Class
Anti-Alzheimer's agent
Pharmacologic Class
N-methyl-D-aspartate (NMDA) receptor antagonist
Pregnancy Category
Category B
FDA Approved
Jun 2010
DEA Schedule
Not Controlled
Overview
What is this medicine?
Memantine XR is a medication used to treat moderate to severe Alzheimer's disease. It works by affecting certain chemicals in the brain that are involved in memory and learning. It helps to improve or stabilize mental function and daily activities in some people with Alzheimer's.
How to Use This Medicine
Taking Your Medication
To take this medication correctly, follow your doctor's instructions and read all the information provided. Take the medication with or without food, as directed. It's essential to continue taking the medication as prescribed by your doctor or healthcare provider, even if you're feeling well.
When taking the medication, swallow the capsule whole without chewing or crushing it. Do not take any capsules that appear abnormal or are damaged. If you have difficulty swallowing the capsule whole, you can sprinkle the contents onto applesauce. If you choose to do this, swallow the mixture immediately without chewing.
Storing and Disposing of Your Medication
Store the medication at room temperature in a dry location, avoiding the bathroom. Keep all medications in a secure place, out of the reach of children and pets. Dispose of unused or expired medications properly. Do not flush them down the toilet or pour them down the drain unless instructed to do so. If you're unsure about the best way to dispose of your medication, consult your pharmacist. You may also want to check if there are drug take-back programs available in your area.
What to Do If You Miss a Dose
If you miss a dose, skip it and resume your regular dosing schedule. Do not take two doses at the same time or take extra doses. If you miss taking the medication for several days in a row, contact your doctor before restarting the medication.
To take this medication correctly, follow your doctor's instructions and read all the information provided. Take the medication with or without food, as directed. It's essential to continue taking the medication as prescribed by your doctor or healthcare provider, even if you're feeling well.
When taking the medication, swallow the capsule whole without chewing or crushing it. Do not take any capsules that appear abnormal or are damaged. If you have difficulty swallowing the capsule whole, you can sprinkle the contents onto applesauce. If you choose to do this, swallow the mixture immediately without chewing.
Storing and Disposing of Your Medication
Store the medication at room temperature in a dry location, avoiding the bathroom. Keep all medications in a secure place, out of the reach of children and pets. Dispose of unused or expired medications properly. Do not flush them down the toilet or pour them down the drain unless instructed to do so. If you're unsure about the best way to dispose of your medication, consult your pharmacist. You may also want to check if there are drug take-back programs available in your area.
What to Do If You Miss a Dose
If you miss a dose, skip it and resume your regular dosing schedule. Do not take two doses at the same time or take extra doses. If you miss taking the medication for several days in a row, contact your doctor before restarting the medication.
Lifestyle & Tips
- Take the capsule once daily at bedtime, with or without food.
- Swallow the capsule whole; do not chew, crush, or divide it.
- If you cannot swallow the capsule whole, you may open it and sprinkle the contents on a small amount of applesauce. Swallow the mixture immediately without chewing.
- Do not take a double dose if you miss a dose. Skip the missed dose and take your next dose at the regular time.
- Inform your doctor about all other medications you are taking, including over-the-counter drugs and herbal supplements.
Available Forms & Alternatives
Dosing & Administration
Adult Dosing
Standard Dose:
Initial: 7 mg once daily. Titrate weekly by 7 mg increments to a target maintenance dose of 28 mg once daily.
Dose Range:
7 - 28 mg
Condition-Specific Dosing:
maintenance:
28 mg once daily
Pediatric Dosing
Neonatal:
Not established
Infant:
Not established
Child:
Not established
Adolescent:
Not established
Dose Adjustments
Renal Impairment:
Mild:
No dosage adjustment needed (CrCl 50-80 mL/min)
Moderate:
Maximum recommended dose is 14 mg once daily (CrCl 30-49 mL/min)
Severe:
Maximum recommended dose is 14 mg once daily (CrCl 5-29 mL/min)
Dialysis:
Not specifically studied, but likely similar to severe impairment. Caution and close monitoring advised.
Hepatic Impairment:
Mild:
No dosage adjustment needed
Moderate:
No dosage adjustment needed
Severe:
Use with caution; dosage adjustment may be necessary but specific recommendations are not available. Close monitoring advised.
Pharmacology
Mechanism of Action
Memantine is a low to moderate affinity, uncompetitive (open-channel) NMDA receptor antagonist. It binds to the NMDA receptor-operated cation channels with a higher affinity for the NMDA receptor than for the PCP site. It is thought to exert its therapeutic effect by blocking the effects of abnormally elevated tonic levels of glutamate, which may contribute to the neuronal dysfunction observed in Alzheimer's disease.
Pharmacokinetics
Absorption:
Bioavailability:
Approximately 100%
Tmax:
Approximately 9-12 hours (extended-release)
FoodEffect:
Food does not affect the extent of absorption of memantine extended-release capsules.
Distribution:
Vd:
Approximately 9-11 L/kg
ProteinBinding:
Approximately 45%
CnssPenetration:
Yes
Elimination:
HalfLife:
Approximately 80 hours (extended-release)
Clearance:
Renal clearance is the primary route of elimination. Clearance is reduced in renal impairment.
ExcretionRoute:
Renal (urine)
Unchanged:
Approximately 48% (unchanged drug in urine)
Pharmacodynamics
OnsetOfAction:
Gradual, due to titration schedule and mechanism of action. Clinical effects typically observed over weeks.
PeakEffect:
Not acutely defined; clinical benefit is observed with chronic dosing.
DurationOfAction:
Sustained due to long half-life and extended-release formulation, allowing once-daily dosing.
Safety & Warnings
Side Effects
Urgent Side Effects: Seek Medical Attention Immediately
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek medical help right away:
- Signs of an allergic reaction, such as rash, hives, itching, red, swollen, blistered, or peeling skin (with or without fever), wheezing, tightness in the chest or throat, trouble breathing, swallowing, or talking, unusual hoarseness, or swelling of the mouth, face, lips, tongue, or throat
- Feeling confused
Other Possible Side Effects
Like all medications, this drug can cause side effects. However, many people do not experience any side effects or only have mild ones. If you are bothered by any of the following side effects or if they do not go away, contact your doctor or seek medical help:
- Dizziness or headache
- Diarrhea or constipation
Important Note: This list does not include all possible side effects. If you have questions or concerns about side effects, consult your doctor. For medical advice about side effects, contact your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek medical help right away:
- Signs of an allergic reaction, such as rash, hives, itching, red, swollen, blistered, or peeling skin (with or without fever), wheezing, tightness in the chest or throat, trouble breathing, swallowing, or talking, unusual hoarseness, or swelling of the mouth, face, lips, tongue, or throat
- Feeling confused
Other Possible Side Effects
Like all medications, this drug can cause side effects. However, many people do not experience any side effects or only have mild ones. If you are bothered by any of the following side effects or if they do not go away, contact your doctor or seek medical help:
- Dizziness or headache
- Diarrhea or constipation
Important Note: This list does not include all possible side effects. If you have questions or concerns about side effects, consult your doctor. For medical advice about side effects, contact your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Seek Immediate Medical Attention If You Experience:
- Severe dizziness or lightheadedness
- Severe headache
- New or worsening confusion
- Hallucinations
- Difficulty urinating or changes in urine output
- Unusual weakness or tiredness
Before Using This Medicine
Before Taking This Medication: Important Information to Share with Your Doctor
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction you experienced, including any symptoms that occurred.
All medications you are currently taking, including prescription and over-the-counter (OTC) drugs, natural products, and vitamins. This is crucial to avoid potential interactions between this medication and other substances.
* Any existing health problems, as this medication may interact with certain conditions.
To ensure your safety, it is vital to verify that this medication can be taken with all your current medications and health conditions. Never start, stop, or adjust the dosage of any medication without first consulting your doctor.
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction you experienced, including any symptoms that occurred.
All medications you are currently taking, including prescription and over-the-counter (OTC) drugs, natural products, and vitamins. This is crucial to avoid potential interactions between this medication and other substances.
* Any existing health problems, as this medication may interact with certain conditions.
To ensure your safety, it is vital to verify that this medication can be taken with all your current medications and health conditions. Never start, stop, or adjust the dosage of any medication without first consulting your doctor.
Precautions & Cautions
It is essential to inform all of your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication. If you are pregnant, planning to become pregnant, or are breast-feeding, be sure to discuss this with your doctor. You and your doctor will need to carefully weigh the benefits and risks of using this medication to ensure the best possible outcome for both you and your baby.
Overdose Information
Overdose Symptoms:
- Severe dizziness
- Agitation
- Confusion
- Hallucinations
- Seizures
- Slowed heart rate
- Vomiting
- Unconsciousness
What to Do:
Seek immediate medical attention or call Poison Control at 1-800-222-1222. Treatment is generally supportive.
Drug Interactions
Moderate Interactions
- Drugs that are renally eliminated via active tubular secretion (e.g., cimetidine, ranitidine, quinidine, procainamide, trimethoprim, amantadine, nicotine, hydrochlorothiazide): Co-administration may alter plasma levels of either drug.
- Other NMDA antagonists (e.g., amantadine, ketamine, dextromethorphan): Increased risk of adverse reactions due to additive effects.
- Carbonic anhydrase inhibitors (e.g., acetazolamide) or sodium bicarbonate: May decrease memantine renal clearance by alkalinizing urine, leading to increased memantine plasma levels.
Monitoring
Baseline Monitoring
Renal function (CrCl)
Rationale: To determine appropriate starting and maximum dose, especially in patients with impaired renal function.
Timing: Prior to initiation of therapy
Routine Monitoring
Clinical response (cognitive and functional status)
Frequency: Periodically, as clinically indicated (e.g., every 3-6 months)
Target: Stabilization or improvement in symptoms of Alzheimer's disease
Action Threshold: Lack of efficacy or worsening symptoms may warrant re-evaluation of treatment or dose.
Adverse effects (e.g., dizziness, headache, confusion, constipation)
Frequency: Regularly, especially during dose titration and initiation
Target: Minimization of side effects
Action Threshold: Persistent or severe adverse effects may require dose reduction or discontinuation.
Symptom Monitoring
- Dizziness
- Headache
- Confusion
- Constipation
- Diarrhea
- Hallucinations
- Hypertension
- Somnolence
- Vomiting
Special Patient Groups
Pregnancy
Category B. Animal studies have not shown evidence of harm to the fetus, but there are no adequate and well-controlled studies in pregnant women. Use only if clearly needed.
Trimester-Specific Risks:
First Trimester:
Low risk based on animal data, but human data lacking.
Second Trimester:
Low risk based on animal data, but human data lacking.
Third Trimester:
Low risk based on animal data, but human data lacking.
Lactation
It is not known whether memantine is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when memantine is administered to a nursing mother. The decision to breastfeed during treatment should consider the potential for infant exposure, the benefits of breastfeeding to the infant, and the benefits of treatment to the mother.
Infant Risk:
Not available (potential for unknown risk)
Pediatric Use
Safety and effectiveness in pediatric patients have not been established. Not indicated for use in children.
Geriatric Use
No specific dosage adjustment is required based solely on age. However, geriatric patients are more likely to have decreased renal function, which necessitates dose adjustment based on creatinine clearance.
Clinical Information
Clinical Pearls
- Memantine XR is typically initiated at a low dose (7 mg) and titrated weekly to the target dose of 28 mg to minimize side effects.
- It can be taken with or without food, and the capsule can be opened and sprinkled on applesauce for patients with swallowing difficulties.
- Unlike cholinesterase inhibitors, memantine can be used in patients with severe Alzheimer's disease.
- Monitor renal function, especially in elderly patients, as dose adjustments are crucial for renal impairment.
- Patients should be advised to avoid sudden discontinuation, although withdrawal symptoms are not typically severe for memantine.
Alternative Therapies
- Donepezil (Aricept)
- Rivastigmine (Exelon)
- Galantamine (Razadyne)
Cost & Coverage
Average Cost:
Varies widely, typically $300-$500+ per 30 capsules (28mg)
Generic Available:
Yes
Insurance Coverage:
Tier 2 or 3 (Brand), Tier 1 (Generic)
General Drug Facts
If your symptoms or health issues persist or worsen, it's essential to contact your doctor for further guidance. To ensure your safety, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so be sure to check with your pharmacist for more information. If you have any questions or concerns about this medication, don't hesitate to discuss them with your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek emergency medical attention. When seeking help, be prepared to provide details about the overdose, including the medication taken, the amount, and the time it occurred.