Memantine Tablets Titration Pak
It is used to treat dementia in people with Alzheimer's disease.
Drug Class
N-methyl-D-aspartate (NMDA) receptor antagonist
Pharmacologic Class
NMDA receptor antagonist
Pregnancy Category
B
FDA Approved
Oct 2003
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 helping to balance certain natural substances in the brain, which can improve memory, awareness, and the ability to perform daily activities. It is not a cure for Alzheimer's, but it can help slow down the worsening of symptoms.
How to Use This Medicine
Taking Your Medication
To use this medication correctly, follow your doctor's instructions and read all the information provided. Take your medication as directed, with or without food. Continue taking it even if you feel well, unless your doctor or healthcare provider advises you to stop.
Storing and Disposing of Your Medication
Store your medication at room temperature in a dry place, avoiding the bathroom. Keep all medications in a safe 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. If you have questions about disposal, consult your pharmacist. You may also want to check if there are drug take-back programs in your area.
Missing a Dose
If you miss a dose, skip it and take your next dose at the usual time. Do not take two doses at once or extra doses. If you miss taking your medication for several days in a row, contact your doctor before restarting your medication regimen.
To use this medication correctly, follow your doctor's instructions and read all the information provided. Take your medication as directed, with or without food. Continue taking it even if you feel well, unless your doctor or healthcare provider advises you to stop.
Storing and Disposing of Your Medication
Store your medication at room temperature in a dry place, avoiding the bathroom. Keep all medications in a safe 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. If you have questions about disposal, consult your pharmacist. You may also want to check if there are drug take-back programs in your area.
Missing a Dose
If you miss a dose, skip it and take your next dose at the usual time. Do not take two doses at once or extra doses. If you miss taking your medication for several days in a row, contact your doctor before restarting your medication regimen.
Lifestyle & Tips
- Take exactly as prescribed, usually once or twice daily. The titration pack helps you gradually increase the dose to reduce side effects.
- Do not crush, chew, or break extended-release tablets; swallow them whole.
- Maintain a consistent daily routine.
- Engage in mentally stimulating activities.
- Maintain a healthy diet and regular physical activity as tolerated.
- Inform your doctor about all other medications, supplements, and herbal products you are taking.
Available Forms & Alternatives
Dosing & Administration
Adult Dosing
Standard Dose:
Initial: 5 mg once daily. Titrate weekly by 5 mg/day increments to a target dose of 20 mg/day. (e.g., Week 1: 5 mg/day, Week 2: 10 mg/day, Week 3: 15 mg/day, Week 4: 20 mg/day).
Dose Range:
5 - 20 mg
Condition-Specific Dosing:
moderateToSevereAlzheimersDisease:
Target dose 20 mg/day, administered as 10 mg twice daily or 20 mg once daily (extended-release).
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:
Maximum recommended dose is 10 mg/day (CrCl 30-49 mL/min).
Severe:
Maximum recommended dose is 5 mg/day (CrCl 5-29 mL/min).
Dialysis:
Not well studied; consider 5 mg/day maximum dose with close monitoring.
Hepatic Impairment:
Mild:
No dosage adjustment necessary.
Moderate:
No dosage adjustment necessary.
Severe:
Not studied; use with caution and close monitoring.
Pharmacology
Mechanism of Action
Memantine is a non-competitive antagonist of N-methyl-D-aspartate (NMDA) receptors. It binds to the NMDA receptor-operated cation channels with moderate affinity and voltage-dependency. It blocks the effects of abnormally elevated tonic levels of glutamate, which are thought to contribute to neuronal dysfunction in Alzheimer's disease, without interfering with the physiological activation of NMDA receptors essential for normal memory and learning.
Pharmacokinetics
Absorption:
Bioavailability:
Approximately 100%
Tmax:
3-7 hours
FoodEffect:
Minimal effect on absorption; can be taken with or without food.
Distribution:
Vd:
9-11 L/kg
ProteinBinding:
Approximately 45%
CnssPenetration:
Yes
Elimination:
HalfLife:
60-80 hours
Clearance:
Primarily renal clearance; clearance is reduced in alkaline urine.
ExcretionRoute:
Renal
Unchanged:
48% (oral solution), 75-80% (tablet)
Pharmacodynamics
OnsetOfAction:
Gradual, due to titration; clinical effects may take weeks to become apparent.
PeakEffect:
Steady state plasma concentrations are reached within 6-11 days.
DurationOfAction:
Long half-life supports once-daily dosing (extended-release) or twice-daily dosing (immediate-release).
Safety & Warnings
Side Effects
Serious Side Effects: Seek Medical Help Right Away
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 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. While 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 do not go away, contact your doctor:
Dizziness or headache
Diarrhea or constipation
Reporting Side Effects
This list is not exhaustive, and you may experience other side effects. If you have questions or concerns about side effects, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch. Your doctor can provide medical advice about side effects.
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 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. While 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 do not go away, contact your doctor:
Dizziness or headache
Diarrhea or constipation
Reporting Side Effects
This list is not exhaustive, and you may experience other side effects. If you have questions or concerns about side effects, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch. Your doctor can provide medical advice about side effects.
Seek Immediate Medical Attention If You Experience:
- Severe dizziness or lightheadedness
- Worsening confusion or agitation
- Hallucinations (seeing or hearing things that are not there)
- Seizures
- Difficulty urinating or changes in urination
- Unusual tiredness or weakness
- Severe headache
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 as a result of the allergy.
Potential interactions with other medications or health conditions. This medication may affect or be affected by other drugs or health problems, so it is crucial to disclose all relevant information.
To ensure safe treatment, provide your doctor and pharmacist with a comprehensive list of:
All prescription and over-the-counter (OTC) medications you are taking
Natural products and vitamins you are using
* Any health problems you have
Carefully review your medications and health conditions with your doctor to confirm that it is safe to take this medication. Do not initiate, discontinue, or modify the dose 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 symptoms you experienced as a result of the allergy.
Potential interactions with other medications or health conditions. This medication may affect or be affected by other drugs or health problems, so it is crucial to disclose all relevant information.
To ensure safe treatment, provide your doctor and pharmacist with a comprehensive list of:
All prescription and over-the-counter (OTC) medications you are taking
Natural products and vitamins you are using
* Any health problems you have
Carefully review your medications and health conditions with your doctor to confirm that it is safe to take this medication. Do not initiate, discontinue, or modify the dose of any medication without first consulting your doctor.
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 this medication to both you and your baby.
Overdose Information
Overdose Symptoms:
- Agitation
- Confusion
- Hallucinations
- Seizures
- Stupor
- Coma
- Hypertonia (muscle rigidity)
- Ataxia (loss of coordination)
- Vomiting
- Vertigo (spinning sensation)
- Bradycardia (slow heart rate)
What to Do:
In case of suspected overdose, seek immediate medical attention. Call 911 or Poison Control at 1-800-222-1222. Treatment is supportive and may include gastric lavage, activated charcoal, and symptomatic management.
Drug Interactions
Major Interactions
- Drugs that alkalinize urine (e.g., carbonic anhydrase inhibitors, sodium bicarbonate): May decrease memantine renal clearance, leading to increased plasma levels and potential toxicity.
Moderate Interactions
- Other NMDA antagonists (e.g., amantadine, ketamine, dextromethorphan): Concomitant use may lead to additive pharmacodynamic effects and increased risk of CNS toxicity (e.g., confusion, hallucinations, seizures).
- Cimetidine, Ranitidine, Quinidine, Nicotine: May alter memantine excretion via renal tubular secretion, potentially increasing memantine levels.
Monitoring
Baseline Monitoring
Cognitive function assessment
Rationale: To establish baseline cognitive status and track disease progression/response to treatment.
Timing: Prior to initiation of therapy
Renal function (CrCl)
Rationale: To determine appropriate initial dosing and guide dose adjustments in patients with renal impairment.
Timing: Prior to initiation of therapy
Routine Monitoring
Cognitive function assessment
Frequency: Periodically (e.g., every 6-12 months or as clinically indicated)
Target: Improvement or stabilization of cognitive symptoms
Action Threshold: Significant decline in cognitive function may warrant re-evaluation of treatment plan.
Adverse effects monitoring (e.g., dizziness, headache, confusion, constipation)
Frequency: Regularly, especially during titration and dose changes
Target: Minimization of intolerable side effects
Action Threshold: Persistent or severe adverse effects may require dose reduction or discontinuation.
Symptom Monitoring
- Worsening confusion or disorientation
- Increased agitation or aggression
- Hallucinations or delusions
- Seizures
- Severe dizziness or lightheadedness
- Falls
- Urinary retention or difficulty urinating
Special Patient Groups
Pregnancy
Pregnancy Category B. Animal studies have not shown evidence of teratogenicity or direct harm to the fetus. There are no adequate and well-controlled studies in pregnant women. Memantine should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
Trimester-Specific Risks:
First Trimester:
No specific human data; animal studies showed no increased risk of malformations.
Second Trimester:
No specific human data.
Third Trimester:
No specific human data.
Lactation
Memantine is excreted in breast milk in low concentrations. The effects on a breastfed infant are unknown. Caution should be exercised when memantine is administered to a nursing mother.
Infant Risk:
Unknown; potential for CNS effects (e.g., sedation, irritability) in the infant, though unlikely given low levels. Monitor infant for adverse effects.
Pediatric Use
Safety and effectiveness in pediatric patients have not been established. Memantine is not indicated for use in children.
Geriatric Use
Memantine is primarily used in the geriatric population. Dose adjustments are necessary for elderly patients with renal impairment. Close monitoring for adverse effects, particularly dizziness and confusion, is recommended.
Clinical Information
Clinical Pearls
- Memantine is typically used for moderate to severe Alzheimer's disease, often in combination with a cholinesterase inhibitor (e.g., donepezil).
- The titration schedule is crucial to minimize common side effects like dizziness and confusion. Adherence to the titration pack is important.
- It is not a cure for Alzheimer's but can help manage symptoms and may slow the rate of decline in some patients.
- Monitor for changes in mental status, gait, and balance, especially during dose escalation.
- Patients with severe renal impairment require significant dose reduction.
- Counsel patients and caregivers on the importance of consistent dosing and reporting any new or worsening symptoms.
Alternative Therapies
- Cholinesterase inhibitors (e.g., donepezil, rivastigmine, galantamine) for mild to moderate Alzheimer's disease, or in combination with memantine for moderate to severe disease.
Cost & Coverage
Average Cost:
Variable; typically $10-$50 for generic 30 tablets (5mg, 10mg) per 30 tablets
Generic Available:
Yes
Insurance Coverage:
Generic memantine is typically covered as a Tier 1 or Tier 2 medication by most prescription drug plans. Brand-name versions may be Tier 3 or higher.
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 reach out to 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 medication, including the amount taken and the time it happened, to facilitate prompt and effective treatment.