Memantine ER 14mg Capsules
It is used to treat dementia in people with Alzheimer's disease.
Drug Class
Agents for Alzheimer's Disease
Pharmacologic Class
N-methyl-D-aspartate (NMDA) Receptor Antagonist
Pregnancy Category
Category B
FDA Approved
Jun 2013
DEA Schedule
Not Controlled
Overview
What is this medicine?
Memantine 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 may help improve memory, awareness, and the ability to perform daily activities, or slow down the worsening of these symptoms.
How to Use This Medicine
Taking Your Medication Correctly
To ensure you get the most benefit from your medication, follow these steps:
Take your medication exactly as directed by your doctor. Read all the information provided with your prescription and follow the instructions carefully.
You can take this medication with or without food.
Continue taking your medication as prescribed by your doctor or healthcare provider, even if you start to feel better.
Swallow the capsules whole; do not chew or crush them.
Do not take any capsules that appear damaged or abnormal.
If you have difficulty swallowing the capsules whole, you can sprinkle the contents onto applesauce. If you do this, swallow the mixture immediately without chewing.
Storing and Disposing of Your Medication
To keep your medication safe and effective:
Store your medication at room temperature in a dry place, avoiding the bathroom.
Keep all medications in a secure location, 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 by your pharmacist.
Check with your pharmacist for guidance on the best way to dispose of your medication. You may also want to explore drug take-back programs in your area.
What to Do If You Miss a Dose
If you miss a dose of your medication:
Skip the missed dose and resume your regular dosing schedule.
Do not take two doses at the same time or take extra doses.
* If you miss taking your medication for several days in a row, contact your doctor before restarting your medication.
To ensure you get the most benefit from your medication, follow these steps:
Take your medication exactly as directed by your doctor. Read all the information provided with your prescription and follow the instructions carefully.
You can take this medication with or without food.
Continue taking your medication as prescribed by your doctor or healthcare provider, even if you start to feel better.
Swallow the capsules whole; do not chew or crush them.
Do not take any capsules that appear damaged or abnormal.
If you have difficulty swallowing the capsules whole, you can sprinkle the contents onto applesauce. If you do this, swallow the mixture immediately without chewing.
Storing and Disposing of Your Medication
To keep your medication safe and effective:
Store your medication at room temperature in a dry place, avoiding the bathroom.
Keep all medications in a secure location, 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 by your pharmacist.
Check with your pharmacist for guidance on the best way to dispose of your medication. You may also want to explore drug take-back programs in your area.
What to Do If You Miss a Dose
If you miss a dose of your medication:
Skip the missed dose and resume your regular dosing schedule.
Do not take two doses at the same time or take extra doses.
* If you miss taking your medication for several days in a row, contact your doctor before restarting your medication.
Lifestyle & Tips
- Take the capsule whole; do not crush, chew, or divide. If unable to swallow, the capsule may be opened and the contents sprinkled on a small amount of applesauce and swallowed immediately.
- Take with or without food.
- Take at approximately the same time each day.
- Do not stop taking memantine without consulting your doctor.
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:
moderate-to-severe Alzheimer's disease:
Initial: 7 mg once daily. Titrate weekly by 7 mg increments to a target maintenance dose of 28 mg once daily. The 14 mg dose is part of this titration schedule.
Pediatric Dosing
Neonatal:
Not established
Infant:
Not established
Child:
Not established
Adolescent:
Not established
Dose Adjustments
Renal Impairment:
Mild:
No dosage adjustment necessary (CrCl 50-80 mL/min).
Moderate:
Initial: 7 mg once daily. Target maintenance dose: 14 mg once daily (CrCl 30-49 mL/min).
Severe:
Initial: 7 mg once daily. Target maintenance dose: 7 mg once daily (CrCl 5-29 mL/min).
Dialysis:
Not specifically studied, but likely similar to severe impairment. Use with caution and monitor closely.
Hepatic Impairment:
Mild:
No dosage adjustment necessary.
Moderate:
No dosage adjustment necessary.
Severe:
Use with caution; specific dosage recommendations are not available. Memantine is minimally metabolized by the liver.
Pharmacology
Mechanism of Action
Memantine is a low-to-moderate affinity uncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist. It binds to the NMDA receptor-operated cation channels with a voltage-dependent block, preventing the prolonged influx of Ca2+ ions that can lead to neuronal dysfunction and cell death (excitotoxicity) in neurodegenerative disorders like Alzheimer's disease, while allowing for normal physiological activation of the receptor.
Pharmacokinetics
Absorption:
Bioavailability:
Approximately 100%
Tmax:
9-12 hours (extended-release)
FoodEffect:
Food does not affect the extent of absorption of memantine extended-release capsules.
Distribution:
Vd:
9-11 L/kg
ProteinBinding:
Approximately 45%
CnssPenetration:
Yes
Elimination:
HalfLife:
Approximately 80 hours (extended-release)
Clearance:
Not readily available as a single rate, primarily renal clearance.
ExcretionRoute:
Renal (urine)
Unchanged:
Approximately 48% (unchanged in urine)
Pharmacodynamics
OnsetOfAction:
Gradual, due to titration schedule and mechanism of action. Clinical effects may be observed over weeks.
PeakEffect:
Steady-state concentrations are reached within approximately 7 days with once-daily dosing.
DurationOfAction:
Due to long half-life, effects persist with once-daily dosing.
Safety & Warnings
Side Effects
Urgent Side Effects: Seek Medical Help Right Away
While rare, some people may experience severe and potentially life-threatening side effects when taking this medication. If you notice any of the following symptoms, contact your doctor or seek immediate medical attention:
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
+ Swelling of the mouth, face, lips, tongue, or throat
Feeling confused
Other Possible Side Effects
Like all medications, this drug can cause side effects. Although many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you experience any of the following side effects or any other unusual symptoms that bother you or persist, contact your doctor for advice:
Dizziness or headache
Diarrhea or constipation
Note: This list is not exhaustive, and you may experience other side effects not mentioned here. If you have questions or concerns about side effects, don't hesitate to reach out to your doctor.
Reporting Side Effects
To report side effects, you can contact the FDA at 1-800-332-1088 or visit their website at https://www.fda.gov/medwatch. Your doctor is also available to provide guidance on managing side effects.
While rare, some people may experience severe and potentially life-threatening side effects when taking this medication. If you notice any of the following symptoms, contact your doctor or seek immediate medical attention:
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
+ Swelling of the mouth, face, lips, tongue, or throat
Feeling confused
Other Possible Side Effects
Like all medications, this drug can cause side effects. Although many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you experience any of the following side effects or any other unusual symptoms that bother you or persist, contact your doctor for advice:
Dizziness or headache
Diarrhea or constipation
Note: This list is not exhaustive, and you may experience other side effects not mentioned here. If you have questions or concerns about side effects, don't hesitate to reach out to your doctor.
Reporting Side Effects
To report side effects, you can contact the FDA at 1-800-332-1088 or visit their website at https://www.fda.gov/medwatch. Your doctor is also available to provide guidance on managing side effects.
Seek Immediate Medical Attention If You Experience:
- Severe dizziness or lightheadedness
- New or worsening confusion or hallucinations
- Seizures
- Difficulty urinating or changes in urination
- 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 symptoms you experienced.
All medications you are currently taking, including prescription and over-the-counter (OTC) drugs, natural products, and vitamins. This will help your doctor identify potential interactions.
* Any existing health problems, as this medication may interact with certain conditions.
To ensure your safety, it is crucial to verify that this medication can be taken with all your current medications and health conditions. Always consult your doctor before starting, stopping, or changing the dose of any medication.
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 symptoms you experienced.
All medications you are currently taking, including prescription and over-the-counter (OTC) drugs, natural products, and vitamins. This will help your doctor identify potential interactions.
* Any existing health problems, as this medication may interact with certain conditions.
To ensure your safety, it is crucial to verify that this medication can be taken with all your current medications and health conditions. Always consult your doctor before starting, stopping, or changing the dose of any medication.
Precautions & Cautions
It is essential to inform all 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
- Diarrhea
- Weakness
What to Do:
Seek immediate medical attention or call Poison Control at 1-800-222-1222. Treatment is generally supportive.
Drug Interactions
Major Interactions
- Drugs that increase urinary pH (e.g., carbonic anhydrase inhibitors, sodium bicarbonate): May decrease memantine renal clearance, leading to increased plasma levels and potential toxicity.
- Other NMDA antagonists (e.g., amantadine, ketamine, dextromethorphan): Coadministration may potentiate adverse effects, particularly CNS effects.
Moderate Interactions
- Hydrochlorothiazide (HCTZ): May reduce memantine plasma levels.
- Cimetidine, Ranitidine, Quinidine, Nicotine, Procainamide: May alter memantine renal tubular secretion, potentially increasing memantine levels.
Monitoring
Baseline Monitoring
Renal function (CrCl)
Rationale: Memantine is primarily renally eliminated; dosage adjustments are required in moderate to severe renal impairment.
Timing: Prior to initiation of therapy.
Routine Monitoring
Clinical response and tolerability
Frequency: Regularly, especially during titration and dose changes.
Target: Improved cognitive function, reduced behavioral symptoms, or stabilization of decline.
Action Threshold: Significant adverse effects or lack of therapeutic benefit may warrant dose adjustment or discontinuation.
Blood pressure
Frequency: Periodically, especially in patients with cardiovascular comorbidities.
Target: Within normal limits for the patient.
Action Threshold: Significant hypertension or hypotension.
Symptom Monitoring
- Dizziness
- Headache
- Confusion
- Constipation
- Diarrhea
- Hallucinations
- Agitation
- Somnolence
- Urinary incontinence
Special Patient Groups
Pregnancy
Use during pregnancy should only be considered if the potential benefit justifies the potential risk to the fetus. Animal studies have shown no direct harmful effects with respect to pregnancy, embryonic/fetal development, parturition, or postnatal development.
Trimester-Specific Risks:
First Trimester:
Limited human data; animal studies show no teratogenicity.
Second Trimester:
Limited human data.
Third Trimester:
Limited human data.
Lactation
Memantine is excreted in human milk. Due to the potential for serious adverse reactions in the breastfed infant, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.
Infant Risk:
L3 - Moderate risk. Potential for CNS effects (e.g., sedation, agitation) in infant due to long half-life and excretion into milk.
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 renal impairment, which necessitates dose adjustment.
Clinical Information
Clinical Pearls
- Memantine ER is typically initiated at a low dose and titrated up to minimize gastrointestinal and CNS side effects.
- It can be taken with or without food. The capsules should be swallowed whole or opened and sprinkled on applesauce.
- Patients should be advised not to crush, chew, or divide the extended-release capsules.
- Monitor for changes in mental status, dizziness, and confusion, especially during dose titration.
- Consider renal function before initiating and during therapy, as dose adjustments are crucial for patients with impaired kidney function.
- Memantine is often used in combination with cholinesterase inhibitors (e.g., donepezil) for moderate to severe Alzheimer's disease.
Alternative Therapies
- Donepezil (Aricept)
- Rivastigmine (Exelon)
- Galantamine (Razadyne)
Cost & Coverage
Average Cost:
$150 - $300 per 30 capsules (14mg)
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 is essential to contact your doctor promptly. 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 it's a good idea to check with your pharmacist. 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 detailed information about the overdose, including the medication taken, the amount, and the time it occurred.