Medications for the treatment of Alzheimer’s disease

Cholinesterase inhibitors can increase communication between nerve cells in the brain. That can reduce the symptoms of the disease. These medications have been approved for use in mild to moderate Alzheimer’s disease. Three different cholinesterase inhibitors are currently available in Germany: donepezil, galantamine and rivastigmine. They are taken as capsules or tablets. Rivastigmine is also available in a patch. Here the drug is absorbed into the body through the skin.

Cholinesterase inhibitors can slightly delay the loss of brain function. Some people who have Alzheimer's are somewhat better able to remember things if they take cholinesterase inhibitors. That can also help people to manage everyday activities like shopping and getting dressed on their own for a little longer.

It isn’t clear whether any of the three medications is more effective than the others. It's also not clear whether these medications can

• improve quality of life,
• reduce related psychological problems such as depression or anxiety, or
• delay the point at which people need full-time care (for example, at a nursing home).

Donepezil already has a beneficial effect at smaller doses, whereas galantamine and rivastigmine only have an effect at a medium or higher dose. All three medications can cause side effects like nausea, vomiting, dizziness or diarrhea. The higher the dose, the more likely they are to occur. Depending on which medication they take, about 1 to 3 out of 10 people feel nauseous or have to vomit. Stomach and bowel problems are less common in people who use rivastigmine patches rather than tablets. But they may cause skin problems such as itching and redness.

Medications containing the drug memantine have been approved for the treatment of moderate to severe Alzheimer’s disease in Germany. They are thought to prevent an excess amount of the substance glutamate from damaging the brain. Glutamate is a chemical messenger that carries nerve signals and helps us to remember things. It is thought that people with Alzheimer’s disease have too much glutamate in their brains, causing their nerve cells to die.

Memantine can somewhat delay the deterioration of cognitive performance in some people. Expressed in numbers: Memantine can delay the deterioration of cognitive performance in about 1 out of 10 people over a time period of six months. There is also some evidence to suggest that people who take memantine carry on doing everyday activities like brushing their teeth, getting dressed or taking public transport somewhat longer. The studies also suggest that it can relieve severe restlessness and improve mood.

It isn’t known whether memantine affects how long people with Alzheimer's can still be cared for at home. There is also no evidence that this treatment helps family members or loved ones, for example by lessening the emotional burden or lowering the need for care.

Memantine seems to be well tolerated overall. But it can’t be ruled out that it might sometimes cause side effects like tiredness or dizziness.

Ginkgo is a herbal product based on extracts from the leaves of the Ginkgo biloba tree. It is believed to have various effects, such as improving blood circulation and protecting nerve cells. Ginkgo is available without a prescription. In Germany and other countries, doctors can also prescribe it for people who have Alzheimer’s disease.

Some studies have shown that people who have mild or moderate Alzheimer’s disease and take the highest tested dose of Ginkgo (240 mg per day) might be better able to perform everyday activities like housework or personal hygiene, at least temporarily. The studies also suggested that, when taken at high doses, Ginkgo could reduce mental health problems and improve people’s ability to remember things. But it isn’t clear how big this effect is.

Gingko is generally quite well tolerated. Sometimes people stop taking Gingko because they experience side effects, such as stomach ache or headache. It can’t be ruled out that Ginkgo may interact with other medications, such as blood-thinning medication.

Alzheimer’s disease often leads to considerable changes in people’s personality and behavior. For example, they might be unusually anxious, distrustful, passive, restless or aggressive. These changes in behavior could be part of the disease, but they might also be a reaction to their environment or to the limitations and losses associated with Alzheimer’s. Aggression, for instance, might be a normal reaction if someone who has Alzheimer's feels patronized. Depression and sleep problems are also common in people who have Alzheimer’s.

For this reason, many people with Alzheimer’s also take medication to reduce mental health problems and abnormal behavior. This may include things like sedatives, antidepressants or antipsychotics. Although these medications might relieve the symptoms, they can also lead to serious side effects such as confusion or a higher risk of falling.

So it’s important to first look for the causes of the problems and try to solve them without using these medications, known as psychotropic medications, if possible. They should only be used if there are no other suitable treatment options. Interactions are also possible when taking several medications at the same time. Before doctors prescribe a new medication, it’s important that they carefully check whether such side effects or interactions are possible, and point out alternative treatment options if necessary.

The treatment of physical symptoms such as pain may be an issue in Alzheimer’s disease too. Pain is sometimes the cause of restlessness and unusual behavior – something which people with advanced Alzheimer’s are often unable to communicate.

The medications currently available can’t greatly influence the course of Alzheimer’s disease. This makes good-quality social and nursing support all the more important. So far, research has shown that cholinesterase inhibitors and memantine (and possibly Ginkgo too) can temporarily reduce some Alzheimer’s symptoms or delay their onset somewhat.

It isn’t possible to say whether one of these types of medications is better than others. Hardly any studies have compared the various medications with each other. There has also been hardly any research on the long-term effects of the medications – most of the studies done so far lasted half a year at the most.

The decision of whether or not to take any of these medications can be discussed with a doctor. But it remains a personal decision that will depend on things like how someone feels about the possible advantages and side effects. Some people may consider the prospect of small improvements to be a good reason to take medication on a daily basis. Others might be put off by the limited benefits and the potential side effects. Further factors that play a role in the decision include whether or not someone has other medical conditions, whether they are already taking medication and, last but not least, how far the disease has already progressed.