Namenda 10mg/5ml Solution
It is used to treat dementia in people with Alzheimer's disease.
Drug Class
N-methyl-D-aspartate (NMDA) receptor antagonist
Pharmacologic Class
Anti-Alzheimer's agent
Pregnancy Category
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 affecting certain chemicals in the brain that are involved in memory and learning, helping to improve or stabilize thinking abilities.
How to Use This Medicine
Taking Your Medication Correctly
To get the most benefit from your medication, follow your doctor's instructions carefully. Read all the information provided with your prescription and follow the instructions closely. You can take this medication with or without food. Continue taking your medication as directed by your doctor or healthcare provider, even if you start to feel better.
When taking the liquid form of this medication, measure your dose carefully using the measuring device that comes with it. Do not mix the medication with any other liquid.
Storing and Disposing of Your Medication
Store your medication at room temperature in a dry place, away from the bathroom. Keep all medications in a safe location, out of the reach of children and pets. Dispose of any unused or expired medication properly. Do not flush medication down the toilet or pour it down the drain unless instructed to do so by your pharmacist. If you have questions about disposing of your medication, ask your pharmacist. You may also want to check if there are any drug take-back programs in your area.
What to Do If You Miss a Dose
If you miss a dose, skip it and take your next dose at the usual time. 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 get the most benefit from your medication, follow your doctor's instructions carefully. Read all the information provided with your prescription and follow the instructions closely. You can take this medication with or without food. Continue taking your medication as directed by your doctor or healthcare provider, even if you start to feel better.
When taking the liquid form of this medication, measure your dose carefully using the measuring device that comes with it. Do not mix the medication with any other liquid.
Storing and Disposing of Your Medication
Store your medication at room temperature in a dry place, away from the bathroom. Keep all medications in a safe location, out of the reach of children and pets. Dispose of any unused or expired medication properly. Do not flush medication down the toilet or pour it down the drain unless instructed to do so by your pharmacist. If you have questions about disposing of your medication, ask your pharmacist. You may also want to check if there are any drug take-back programs in your area.
What to Do If You Miss a Dose
If you miss a dose, skip it and take your next dose at the usual time. 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 exactly as prescribed by your doctor. Do not stop taking it suddenly without consulting your doctor.
- Can be taken with or without food.
- Measure the oral solution carefully using the provided dosing device (syringe or pump) to ensure accurate dosing.
- If you miss a dose, take it as soon as you remember, unless it's almost time for your next dose. Do not double dose.
- Report any new or worsening symptoms to your doctor.
- Maintain regular follow-up appointments with your healthcare provider.
Available Forms & Alternatives
Dosing & Administration
Adult Dosing
Standard Dose:
10 mg twice daily (20 mg/day total) after titration
Dose Range:
5 - 20 mg
Condition-Specific Dosing:
moderateToSevereAlzheimersDisease:
Initial 5 mg (2.5 mL) once daily, increasing weekly by 5 mg (2.5 mL) increments to a target dose of 20 mg (10 mL) per day. Doses above 5 mg should be given in two divided doses (e.g., 10 mg twice 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 10 mg (5 mL) per day (CrCl 30-49 mL/min)
Severe:
Maximum recommended dose is 5 mg (2.5 mL) per day (CrCl 5-29 mL/min)
Dialysis:
Not well studied; consider 5 mg/day with close monitoring.
Hepatic Impairment:
Mild:
No dosage adjustment needed
Moderate:
No dosage adjustment needed
Severe:
Not studied; use with caution.
Pharmacology
Mechanism of Action
Memantine is a non-competitive antagonist of N-methyl-D-aspartate (NMDA) receptors. It is thought to exert its therapeutic effect by blocking the effects of abnormally elevated levels of glutamate, which may contribute to the neuronal dysfunction seen in Alzheimer's disease.
Pharmacokinetics
Absorption:
Bioavailability:
Approximately 100%
Tmax:
3-7 hours
FoodEffect:
Minimal; 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
ExcretionRoute:
Renal
Unchanged:
Approximately 48% (in urine)
Pharmacodynamics
OnsetOfAction:
Gradual, over several weeks due to titration and disease progression.
PeakEffect:
Not acutely defined for cognitive improvement; clinical benefit observed over weeks to months.
DurationOfAction:
Long, due to extended half-life, supporting once or twice 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 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 and help you manage any concerns.
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 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 and help you manage any concerns.
Seek Immediate Medical Attention If You Experience:
- Severe dizziness or lightheadedness
- Severe headache
- Confusion or agitation that worsens
- Hallucinations (seeing or hearing things that are not there)
- Seizures
- Difficulty urinating or changes in urination
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.
All medications you are currently taking, including prescription and over-the-counter (OTC) drugs, natural products, and vitamins. This information will help your doctor and pharmacist assess potential interactions between this medication and other substances you are taking.
* 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 safely with all your other 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 symptoms you experienced as a result of the allergy.
All medications you are currently taking, including prescription and over-the-counter (OTC) drugs, natural products, and vitamins. This information will help your doctor and pharmacist assess potential interactions between this medication and other substances you are taking.
* 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 safely with all your other 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 currently 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:
- Agitation
- Confusion
- Hallucinations
- Dizziness
- Somnolence
- Stupor
- Seizures
- Coma
- Bradycardia
- QTc prolongation
- Ventricular tachycardia
- Vertigo
- Vomiting
- Gait disturbance
What to Do:
Seek immediate medical attention or call a poison control center (e.g., 1-800-222-1222). Treatment is generally supportive; no specific antidote.
Drug Interactions
Major Interactions
- Other NMDA antagonists (e.g., amantadine, ketamine, dextromethorphan): Increased risk of CNS toxicity (confusion, hallucinations, seizures).
Moderate Interactions
- Drugs that increase urine pH (e.g., carbonic anhydrase inhibitors, sodium bicarbonate): May decrease memantine renal clearance, leading to increased plasma levels.
- Drugs eliminated by renal tubular secretion (e.g., cimetidine, ranitidine, quinidine, nicotine, procainamide): Potential for altered memantine levels due to competition for renal tubular transport.
Monitoring
Baseline Monitoring
Renal function (CrCl)
Rationale: To determine appropriate initial dosing and maximum daily dose, especially in patients with impaired renal function.
Timing: Prior to initiation of therapy.
Routine Monitoring
Cognitive function (e.g., MMSE, ADAS-Cog)
Frequency: Periodically, as clinically indicated (e.g., every 6-12 months)
Target: Improvement or stabilization of cognitive symptoms
Action Threshold: Significant decline or lack of benefit may warrant re-evaluation of therapy.
Adverse effects (e.g., dizziness, headache, confusion, constipation, hallucinations)
Frequency: Regularly, especially during titration and dose adjustments
Target: Minimization of side effects
Action Threshold: Intolerable side effects may require dose reduction or discontinuation.
Symptom Monitoring
- Worsening confusion
- Agitation
- Hallucinations
- Seizures
- Severe dizziness
- Severe headache
- Urinary retention
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 and potential benefits outweigh potential risks.
Trimester-Specific Risks:
First Trimester:
No specific data indicating increased risk.
Second Trimester:
No specific data indicating increased risk.
Third Trimester:
No specific data indicating increased risk.
Lactation
Memantine is excreted in breast milk in animals. It is unknown if it is excreted in human milk. The decision to breastfeed during memantine therapy should consider the potential for infant exposure, the benefits of breastfeeding to the infant, and the benefits of treatment to the mother. L3 (Moderate risk).
Infant Risk:
Potential for infant exposure and adverse effects; monitor breastfed infant for drowsiness, poor feeding, or developmental milestones.
Pediatric Use
Safety and efficacy have not been established in pediatric patients. 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 dosage adjustment based on creatinine clearance.
Clinical Information
Clinical Pearls
- Titration is crucial to minimize common side effects like dizziness and confusion. Start low and go slow.
- Memantine can be used concomitantly with cholinesterase inhibitors (e.g., donepezil) for moderate to severe Alzheimer's disease.
- The oral solution is useful for patients who have difficulty swallowing tablets.
- Ensure patients and caregivers understand how to accurately measure the oral solution using the provided dosing device.
- Monitor for changes in behavior, mood, or cognitive function, as well as for common side effects.
Alternative Therapies
- Donepezil (Aricept)
- Rivastigmine (Exelon)
- Galantamine (Razadyne)
Cost & Coverage
Average Cost:
Varies widely by pharmacy and insurance plan per 10mg/5ml solution (e.g., 300mL bottle)
Generic Available:
Yes
Insurance Coverage:
Often Tier 1 or Tier 2 for generic; Tier 3 or higher for brand.
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 taken, the amount, and the time it happened.