Does memantine help?

Photo of an older man (PantherMedia / Anna Lurye)

Medications containing the drug memantine are supposed to help people who have Alzheimer’s disease remember things and better manage their daily tasks. Studies show that memantine can somewhat delay the worsening of cognitive (mental) performance. Other abilities important in daily life may also last longer.

There is no cure for Alzheimer’s. A number of different medications and other treatment options aim to relieve the symptoms and slow down the progression of the disease. Non-drug strategies include memory training and the encouragement of social activities. The medications available for treating Alzheimer’s include cholinesterase inhibitors and memantine, as well as the herbal medicine Ginkgo biloba.

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 who have moderate to severe Alzheimer’s. It is believed to help prevent excess levels of the substance glutamate from damaging the brain. Glutamate is a substance responsible for carrying nerve signals. Experiments on animals have suggested that people who have developed Alzheimer’s might also have too much glutamate in their brain. Memantine is meant to prevent excess glutamate from killing the nerve cells, without disturbing the normal transmission of nerve signals.

Assessment of memantine

Several systematic reviews looked into whether people who have Alzheimer's can benefit from memantine.  The researchers were interested in several things, including whether the drugs improved mental (cognitive) performance, relieved mental health problems or made it easier for them to manage everyday tasks. They also looked into whether the medication influenced the need for care. A further aim of their analysis was to determine whether memantine is more or less effective than other medicines like Ginkgo-based products or cholinesterase inhibitors.

The studies compared memantine with a placebo (fake drug), with other medications, or with non-drug treatments. Quite a lot of good-quality studies are available, so it's possible to properly assess the short-term advantages and disadvantages. The benefit after several years of use has not yet been studied.

Memantine can somewhat delay the worsening of some abilities

All of the studies looked at the effects of memantine on abilities that are important in daily life, on cognitive performance, and on mental health problems. Emotional strain 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 manage practical activities of daily life – such as brushing your teeth, getting dressed or taking a bus or tram – worsened over the course of the study in all participants. But the studies suggest that memantine can delay this process.

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

The studies also suggest that it can relieve severe restlessness. There is no information in these studies about whether memantine influences how long people with Alzheimer's can still be cared for at home, though.

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

Side effects

People who took memantine didn't drop out of studies 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. Yet too few people participated in the studies to gather data on possible rare side effects. Also, the participants were in relatively good health, aside from having Alzheimer’s disease. For this reason, it isn't clear how well memantine would be tolerated by people who are also taking medication for other conditions.

Unanswered questions remain

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