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Namenda is a brand-name version of the generic drug memantine. It belongs to a class of drugs called N-methyl-D-aspartate (NMDA) receptor agonists.
Namenda works by slowing neurotoxicity in the brain, which is thought to cause Alzheimer’s disease and other neurodegenerative conditions.
This medication is available by prescription only.
The body clears Namenda at a slower rate when urine pH is high, which can cause drug levels to rise and increase the risk of adverse effects. This may affect people who have health conditions or take medications that raise the pH of their urine.
Namenda is contraindicated for people with a known hypersensitivity to memantine hydrochloride.
Caution is recommended for people with kidney or liver impairments when taking this drug. People with severely reduced kidney or liver function may be prescribed a lower dose of Namenda.¹
Namenda has been approved by the US Food and Drug Administration (FDA) for the treatment of moderate to severe dementia, such as that associated with Alzheimer’s disease.¹
The medication does not slow the progression of the disease, but it has been shown to help with some of the cognitive symptoms when used in combination with other drugs. Patients have experienced a small improvement in mood, behavior, and their ability to think and remember things. It may also slow the rate at which these abilities are lost.² ³
Note that Namenda has not been shown to be effective in mild Alzheimer’s disease.
Immediate-release Namenda is available in the following forms and strengths:⁴
Tablet for oral use: 5mg and 10mg
Solution for oral use: 2mg/mL
Namenda is also available as an extended-release capsule in the following strengths:
7mg, 14mg, 21mg, and 28mg⁵
Your doctor will prescribe Namenda according to:
Your age
The condition being treated and its severity
The form of Namenda prescribed
Any additional medical conditions you may have
Your doctor will typically start you on a low dose and gradually increase it to the level that’s suitable for you. They will eventually prescribe the lowest dose that has the intended effect.
Namenda can be taken with or without food. The tablets should be swallowed whole and not crushed or chewed.
To take the oral solution, use the supplied syringe and withdraw the correct volume of liquid. Squirt it into the corner of your mouth and swallow. Do not mix the solution with other liquids.
Swallow your dose of Namenda XR capsules whole, once daily. If you find the capsule difficult to swallow, open it and sprinkle the contents onto a spoonful of applesauce. Without chewing, quickly swallow this combination.
Namenda should be taken exactly as prescribed. Do not take more or less of it, or take it more frequently than your doctor has suggested.
It may take months to see the desired effects when taking Namenda. Remember, this drug does not cure Alzheimer’s disease.⁶
Do not take Namenda if:
You have a known hypersensitivity to memantine hydrochloride
You take a drug that is contraindicated with Namenda, including drugs that make the urine alkaline
Namenda can cause side effects that range from mild to severe. Make sure you speak to your doctor about possible adverse effects before starting treatment.
The following are some of the more typical side effects that may occur with Namenda:¹
Dizziness
Headache
Confusion
Constipation
Coughing
Vomiting
Body pain
Back pain
Hallucinations
Drowsiness
Fatigue
Trouble breathing
Other common side effects noted specifically with Namenda XR include:⁵
Diarrhea
Influenza
Weight gain
Aggression
Abdominal pain
Urinary incontinence
Low blood pressure
This list of adverse effects is not exhaustive. Speak to your doctor if you develop any of these symptoms while taking the medication.
Take Namenda as prescribed by your doctor to reduce your risk of overdose. If you take too much of this medication, you may experience signs and symptoms of toxicity. These include the following:¹
Agitation
Weakness and lack of energy
Unsteady gait
Slow heart rate
Confusion
Dizziness, vertigo
ECG changes
Increased blood pressure
Lethargy
Hallucinations
Vomiting
Loss of consciousness
Coma
If you experience any of these overdose symptoms, seek emergency medical attention.
Allergic reactions to Namenda are rare, but symptoms to watch out for include the following:
Severe dizziness
Severe rash
Itchy skin
Swelling of the face, tongue, or throat
Loss of consciousness
Stop taking this medication and consult your doctor immediately if you develop signs of an allergic reaction. Call 911 if your reaction is severe.
Studies of the long-term use of Namenda are limited. A 72-week study published in 2018 examining the drug’s long-term effects when taken alongside donepezil found no adverse effects linked to the duration of treatment. The researchers concluded that long-term administration of Namenda was beneficial to patients with moderate to severe Alzheimer’s disease by improving overall clinical symptoms and cognitive function.⁷
Namenda has been designated by the FDA as a pregnancy category B medication. This means⁸
Animal studies have not demonstrated a risk to the fetus.
Studies in humans are limited and inadequate, so the risk of harm to a human fetus is unknown.⁹
Namenda is rarely used by younger people. There hasn’t been enough research on humans to determine if Namenda is harmful to a human fetus. However, researchers observed Namenda use in pregnant rats caused fetal harm at doses much higher than what a human would receive.
Inform your doctor if you are or intend to become pregnant while taking Namenda. This medication should only be taken during pregnancy if your doctor has confirmed the possible benefit outweighs the potential risk.
It is not known if this medication enters breast milk. Speak to your doctor if you are breastfeeding and need to take this medication.
If you forget to take your dose of Namenda, skip the missed dose and continue with your regular schedule. Do not take two doses of Namenda at the same time.
If you miss several doses of Namenda, do not take your next dose until you have spoken to your doctor. You may need to restart treatment at a lower dose to prevent toxicity.¹
Before starting Namenda, make sure your doctor knows about all of the other drugs, nutritional supplements, or natural remedies you are taking. Namenda can interact with other drugs, and this could lead to serious side effects.
Tell your doctor if you are taking any of the following:¹⁰
Acetazolamide (Diamox)
Amantadine
Dextromethorphan (Robitussin, Delsym, Vicks DayQuil Cough, and others)
Methazolamide
Potassium citrate and citric acid (Cytra-K and Polycitra-K)
Sodium bicarbonate (Soda Mint and baking soda)
Sodium citrate and citric acid (Bicitra and Oracit)
Drinking alcohol can worsen symptoms of Alzheimer’s disease and increase your risk of adverse effects, like dizziness. Therefore, it is recommended to avoid drinking alcohol while taking Namenda.
Before you start taking this medication, share the following information with your doctor:
Drug allergies: Tell your doctor if you are allergic to memantine hydrochloride, any other drugs, or any of the components in Namenda tablets, capsules, or oral solution. For a list of ingredients, see your pharmacist or the manufacturer’s patient information.
Medications: Let your doctor know if you are taking any prescription and non-prescription drugs, vitamins, nutritional supplements, and herbal remedies. They may need to adjust the dosage of your medications or closely monitor you for adverse effects.
Medical conditions: Your doctor must know if you have or have ever had seizures, problems urinating, or kidney or liver disease. Tell your doctor if you currently have a urinary tract infection (UTI).
Pregnancy/breastfeeding: Inform your doctor if you are pregnant, planning a pregnancy, or breastfeeding. If you become pregnant while taking Namenda, you’ll need to tell them immediately.
Surgeries: Your doctor should know if you are planning to undergo surgery, including dental surgery. You’ll also need to tell your surgical team that you are taking Namenda.
Your doctor has prescribed this drug because they believe it can help manage your Alzheimer’s disease symptoms. Speak to your doctor before stopping your medication.
2003: Namenda was first approved by the FDA as an oral tablet.
2005: The FDA approved Namenda as an oral solution.¹¹
2010: The FDA approved Namenda ER capsules.¹²
Following these tips could help you take Namenda safely and effectively:
Don’t take this medication without first disclosing to your doctor which other drugs, vitamins, or remedies you take and whether you have other medical conditions.
Don’t take two doses at once to catch up with one you missed. If you have missed taking your doses for a couple of days, you should hold the next dose and call your doctor.
Contact your doctor if any side effects continue, worsen, or bother you.
Aricept (donepezil) and Namenda are both prescribed to people with Alzheimer’s disease to help manage their symptoms.
The medications belong to different drug classes: Namenda is an NMDA receptor agonist, while Aricept is a cholinesterase inhibitor.
Aricept is available as a tablet for oral use and as an orally disintegrating tablet.
Namenda was found to be effective in people with moderate and severe Alzheimer’s disease and showed minimal benefit in people with mild Alzheimer’s disease.
Namenda can slow the progression of dementia symptoms, such as the ability to remember things and think, but it cannot stop or cure dementia.
Sources
Namenda® (memantine hydrochloride) tablets, for oral use initial U.S. approval: 2003 | Access Data
Memantine for the treatment of dementia: A review on its current and future applications (2018)
Namenda (memantine HCl) solution, for oral use initial U.S. approval: 2003 | Access Data
Namenda xr- memantine hydrochloride capsule, extended release namnda xr- memantine hydrochloride kit | DailyMed
Memantine (2022)
Namenda- memantine hydrochloride tablet | DailyMed
Pregnancy medications (2022)
Memantine | MedlinePlus
Drug approval package | U.S. Food and Drug Administration (2005)
Drug approval package | U.S. Food and Drug Administration (2010)
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Here at HealthMatch, we’ve done our best to ensure that the information provided in this article is helpful, up to date, and, most importantly, accurate.
However, we can’t replace the one-to-one advice of a qualified medical practitioner or outline all of the possible risks associated with this particular drug and your circumstances.
It is therefore important for you to note that the information contained in this article does not constitute professional medical or healthcare advice, diagnosis or recommendation of treatment and is not intended to, nor should be used to, replace professional medical advice. This article may not always be up to date and is not exhaustive of all of the risks and considerations relevant to this particular drug. In no circumstances should this article be relied upon without independent consideration and confirmation by a qualified medical practitioner.
Your doctor will be able to explain all possible uses, dosages, precautions, interactions with other drugs, and other potential adverse effects, and you should always talk to them about any kind of medication you are taking, thinking about taking or wanting to stop taking.
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