Therapy of Alzheimer’s disease

Synonyms in a broader sense

Alzheimer disease therapy, dementia therapy, Alzheimer dementia

There is currently no causal therapy for Alzheimer’s disease. Nevertheless, a number of measures can slow down the course of the disease, reduce the Alzheimer symptoms and improve the quality of life of those affected. The symptomatic therapy of dementia is based on the medicinal influence on the brain‘s metabolism of the messenger substances acetylcholine and glutamate, the likewise medicinal treatment of the accompanying symptoms such as psychoses or depression and the non-drug training of the patients’ intellectual abilities.

Various drugs are available to improve the thinking and memory functions in Alzheimer’s disease. For mild to moderate dementia, preparations that intervene in the metabolism of the messenger substance acetylcholine and increase its availability at the circuitry sites in the brain by inhibiting the breakdown of acetylcholine by the enzyme acetycholinesterase (AchE) have proven to be effective. This increase in the concentration of acetylcholine in the brain leads to a temporary improvement in intellectual abilities and everyday competence.

The deterioration can be halted for about a year. These acetycholinesterase inhibitors include donepezil, rivastigmine and galantamine. Compared to older acetycholinesterase inhibitors such as the tacrines, which were previously used in Alzheimer’s therapy, these drugs have fewer side effects, such as nausea, and there is no need for weekly liver enzyme monitoring.

In advanced dementia, therapeutic success can be achieved by influencing the glutamate metabolism in the brain. Drugs such as memantine shield the switching points between the brain cells from the damaging effect of the messenger substance, which is present in excess in Alzheimer’s disease, and thus occupy the binding sites at the receptors as antagonists of glutamate. Thus the learning process, which is influenced by these receptors, is not damaged by the excessive glutamate release.

Memantine can also be combined with acetylcholinesterase inhibitors. So-called nootropics are also used in therapy. Nootropics are drugs without any direct points of attack in the body to which Piracetam and Gingko-Biloba preparations belong.

Piracetam increases the patients’ attention (vigilance) and shows a reduction in the course of the disease in a controlled study. Gingko-Biloba preparations seem to have a small positive effect on the thinking and memory performance. Some ingredients can act as radical scavengers.

However, despite the widespread use of ginkgo biloba preparations, studies have not been able to prove a proven effect. Likewise, vitamin E (tocopherol) and oestrogens show little or no proven positive effect on Alzheimer’s disease. In any case, the treatment of the accompanying psychological symptoms is of primary importance.

However, care must be taken to ensure that no drugs are administered that interfere with the metabolic pathways of the above-mentioned messenger substances in order to avoid a worsening of the dementia symptoms. Selective serotonin reuptake inhibitors (SSRI) such as sertraline or citalopram are preferred to treat depression. Tricyclic antidepressants, on the other hand, are avoided as they reduce the effect of acetylcholine.

In cases of auditory and visual hallucinations and in cases of severe agitation, neuroleptic drugs such as haloperidol or risperidone can be used. Treatment should be started in low doses and should be well controlled, as side effects are common in elderly and organically brain-damaged persons. The same applies to clomethiazole (distraneurin), which can also be taken for agitation. Neuroleptics or trazodone can also be taken for sleep disorders and nocturnal restlessness. Benzodiazepines such as Valium should not be used because they reduce intellectual capacity and often cause contradictory (paradoxical) reactions such as agitation.