Memantine: Uses, Precautions, Administration, Side Effects, Overdose and Drug Studies

It is used to help eliminate symptoms that affect thinking, such as memory loss and confusion.

Memantine is prescribed for people who have dementia associated with Alzheimer’s disease .

Medicines containing the drug memantine are supposed to help people with Alzheimer’s disease remember things and better manage their daily tasks.

Studies show that memantine can delay the worsening of cognitive (mental) performance. Other important skills in daily life can also last longer.

There is no cure for Alzheimer’s. Memantine is not a cure, but it can slow the progression of symptoms in some people. It works by reducing the amount of a brain chemical called glutamate.

This is believed to help decrease damage to brain cells affected by Alzheimer’s disease.

A number of different medications and other treatment options aim to relieve symptoms and slow the progression of the disease. Non-drug strategies include memory training and encouragement of social activities.

Medications available to treat Alzheimer’s include cholinesterase inhibitors and memantine, as well as the herbal medicine Ginkgo biloba.

Memantine will be prescribed by a specialist doctor. It is prescribed for people with moderate or severe Alzheimer’s disease, who for some reason cannot take the other medicines more generally prescribed for Alzheimer’s disease.

It will only start for people who have a caregiver capable of supervising treatment. If you are the caregiver, read this document on behalf of the person receiving memantine.

The effect of memantine

Axura and Ebixa are two of the drugs approved for the treatment of Alzheimer’s in Germany. Both contain the active ingredient memantine. This drug is approved for people with moderate to severe Alzheimer’s.

It is believed to help prevent excessive levels of the substance glutamate from damaging the brain. Glutamate is a substance responsible for carrying nerve signals.

Animal experiments have suggested that people who developed Alzheimer’s may also have too much glutamate in their brains. Memantine is intended to prevent excess glutamate from killing nerve cells, without disturbing the normal transmission of nerve signals.

Precautions

Some drugs are not suitable for people with certain conditions, and sometimes a drug can only be used if special precautions are taken. For these reasons, before you start taking memantine, it is important that your doctor knows:

If you have a problem with the way your kidneys work or any problem with the way your liver works.

Tell your doctor about all the prescription and over-the-counter medicines you use. This includes vitamins, minerals, herbal products, and medications prescribed by other doctors. Don’t start using a new medicine without telling your doctor.

Before taking memantine, tell your doctor if you are using any of the following medications:

Cimetidine (Tagamet); nicotine (Commit, Habitrol, Nicoderm, Nicotrol, Nicorette); ranitidine (Zantac); quinidine (Cardioquin, Quinadex, Quinaglute); Baking soda (Alka-Seltzer, Baking Soda Antacid Home Remedy); antiviral medication such as amantadine (Symmetrel) or rimantadine (Flumadine).

Also cold or cough medicines that contain dextromethorphan; a diuretic (water pill) such as hydrochlorothiazide (HydroDiuril, Hyzaar, Lopressor, Vasoretic, Zestoretic) or triamterene (Dyrenium, Maxzide, Dyazide).

Also medications to treat glaucoma , such as acetazolamide (Diamox), dichlorphenamide (Daranide) or methazolamide (Neptazane, Glauctabs); or an oral diabetes medicine that contains metformin (such as Fortamet, Glucophage, Actoplus Met, Avanda Met, Metaglip, Glucovance).

Management

Before starting treatment, read the manufacturer’s printed information leaflet from inside the package. Your doctor will help you take your tablets / medications exactly as your doctor tells you. Take one dose every day.

Your doctor will start with a 5 mg dose and then gradually increase your dose over the following weeks. This allows your doctor to make sure you have the dose that helps your condition but prevents any unwanted symptoms.

You can take memantine at any time of day that is easier for you to remember, but try to take your doses at the same time of day every day. It can be taken with or without food.

Doses of oral liquid medicine should be measured using the dose pump that comes with the bottle. When opening a bottle for the first time, place the pump in the bottle and ‘prime’ by pressing the pump head five times.

Throw away any solution that comes out of the bottle while doing this. The next time you use the pump, it will deliver a 5 mg dose each time you fully depress it.

Measure the correct dose in a spoon or in a glass of water. If you are not sure what to do or how to use the pump to measure the correct dose, ask your pharmacist to show you. Do not take two doses together to make up for a forgotten dose.

What are the possible side effects of memantine?

Before using memantine, tell your doctor if you are allergic to any drugs, or if you have a seizure, cataracts, liver or kidney disease, or a bladder or kidney infection .

Stop using memantine and call your doctor at once if you have any of these serious side effects:

Cough, chest tightness, fever, shortness of breath; chest pain, fast heart rate; confusion, hallucinations; sudden numbness or weakness, especially on one side of the body; lack of coordination.

Also fainting or seizures (convulsions); urinating less than normal or not at all; pale skin, easy bruising or bleeding, unusual weakness; or increased blood pressure (severe headache, blurred vision, trouble concentrating, chest pain, numbness, seizures).

Less serious side effects may include:

Nausea, vomiting, diarrhea, constipation , loss of appetite; dizziness, tired feeling; weightloss; swelling in your hands or feet; fast heart rate; easy bruising or bleeding, unusual weakness.

Also joint pain; anxiety, aggression; acne; redness or swelling in or around your eyes; or urinating more than usual.

This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effects. Before using memantine, tell your doctor if you are allergic to any drugs or if you have:

Epilepsy or other seizure disorder; waterfalls; liver disease; kidney disease; or a bladder or kidney infection. If you have any of these conditions, you may need a dose adjustment or special tests to safely take memantine.

If you experience any other symptoms that you think may be due to medicine, talk to your doctor or pharmacist for more information.

Overdose

Seek emergency medical attention if you think you have used too much of this medicine.

The liquid form (oral solution) of this medication comes with patient instructions for safe and effective use. Follow these instructions carefully.

Overdose symptoms may include restlessness, drowsiness, unusual behavior, hallucinations, feeling dizzy, or fainting.

Get the most out of your treatment

It may take several weeks before memantine seems to have an effect. Keep taking your doses every day until your doctor tells you otherwise.

Your doctor will want to check your progress every few weeks to make sure the dose is right for you and that you benefit from treatment. Always try to keep these regular medical appointments.

There are several strengths of the memantine tablet available: 5mg, 10mg, 15mg and 20mg. Every time you pick up a new supply, check the label on the box to make sure it is the tablet strength you are expecting.

If you make any major changes to your diet, tell your doctor. This is because your dosage may need adjustments if, for example, you switch from a diet that includes meat to one that only contains vegetables.

If you are going to have an operation or dental treatment, tell the person performing the treatment that you are taking memantine. This is particularly important if you are going to need general anesthesia.

Memantine studies

Several systematic reviews looked at whether people with Alzheimer’s can benefit from memantine.

The researchers were interested in a number of things, including whether the drugs improved mental (cognitive) performance, alleviated mental health problems, or made daily homework easier for them.

They also investigated whether the drug influenced the need for care. Another objective of their analysis was to determine if memantine is more or less effective than other medicines such as Ginkgo biloba-based products or cholinesterase inhibitors.

The studies compared memantine with a placebo (fake drug), with other drugs, or with non-drug treatments. There are many good quality studies available, so short-term advantages and disadvantages can be adequately assessed.

The benefit after several years of use has not yet been studied. Memantine can delay the worsening of some abilities

All studies looked at the effects of memantine on skills that are important in daily life, cognitive performance, and mental health problems.

Emotional stress on family members and loved ones was also included in most of the studies. Less data was collected on the quality of life of those affected or the need for care. So many questions remain unanswered:

The ability to handle practical activities of daily living, such as brushing teeth, getting dressed, or taking a bus or tram, worsened throughout the study in all participants. But studies suggest that memantine can slow down this process.

They also show that memantine can slow down the decline in cognitive performance (like learning or remembering something, for example). Memantine was able to delay the worsening of cognitive performance for a period of six months in about 1 in 10 people.

Studies also suggest that it can alleviate severe restlessness. There is no information in these studies on whether memantine influences the length of care for people with Alzheimer’s at home.

There is also no evidence that this treatment helps lessen the burden on family members or loved ones, for example, by decreasing the need for care or decreasing emotional stress. The effect of memantine does not depend on the age, sex or severity of the disease of the study participants.

Side effects in studies

People who took memantine did not drop out early due to side effects more often than people who took a placebo. This is a sign that memantine was well tolerated.

Overall, the drug didn’t cause more side effects than a placebo, either. However, very few people participated in the studies to collect data on rare possible side effects.

In addition, the participants were in relatively good health, in addition to having Alzheimer’s disease. For this reason, it is not clear how well memantine would be tolerated by people who are also taking medications for other conditions.

Since none of the studies lasted more than 12 months, the consequences of long-term treatment with memantine remain unclear. It is also difficult to judge how memantine compares to other medications or non-drug treatments for Alzheimer’s.