The active ingredient and the effect of cholinesterase inhibitors
Cholinesterase inhibitors are a group of active ingredients that differ slightly in their chemical structure but are characterized by the same basic action. The site of action is the connections between nerve cells (synapses) and the connection between nerve and muscle cells (motor end plate). There, signals are transmitted by the body’s own messenger acetylcholine.
This in turn is broken down by the so-called cholinesterases to regulate or terminate the effect. The cholinesterase inhibitors reduce the effect of the cholinesterase and thus increase the effect of the released acetylcholine. This results in an increased signal transmission at the synapses or motor end plates.
This results in an increased signal transmission at the synapses or motor end plates. The effect of the cholinesterase inhibitor is ultimately an increased activity of the muscles, for example of the bladder or intestine. In the case of the active substances that can also enter the brain and are used to treat Alzheimer’s dementia, signal transmission between the cells is also amplified. By increasing the activity in certain areas of the brain, this should improve memory and concentration or at least slow down mental deterioration.
Side effects of cholinesterase inhibitors
The cell connections at which the cholinesterase inhibitors exert their effect are located in very different organs throughout the body. When a drug containing a cholinesterase is used, therefore, it is never possible to target only one organ or to achieve only a specific effect. The active substance is distributed throughout the body, so that side effects can occur wherever the body uses the messenger substance acetylcholine.
For example, cholinesterase inhibitors:
- Cause bronchial constriction and increased secretion production in the lungs, making breathing more difficult. – At the heart, it can lead to a slowing of the heartbeat (bradycardia). – In addition, the activity of the sweat glands is increased, so that some people complain of increased sweating when they take it.
- Furthermore, there may be complaints of the gastrointestinal tract such as nausea, vomiting or diarrhoea. – Nausea,
- Vomit or
- Diarrhea coming. – Side effects that can affect the brain do not usually occur.
- Most of the cholinesterase inhibitors used do not cross the so-called blood-brain barrier due to their chemical properties. – Only when an effect in the brain is desired (as in Alzheimer’s dementia), cholinesterase inhibitors that can penetrate the brain are used. In this case, side effects can also occur in the brain, which can manifest themselves for example as dizziness or hallucinations. – Nausea,
- Vomit or
- Diarrhea coming.
Interactions of cholinesterase inhibitors
Due to their effect on a large number of organs throughout the body, cholinesterase inhibitors can interact with other drugs in a variety of ways. The prescribing physician must therefore assess, based on the patient’s further medication, whether interactions are to be feared and whether the cholinesterase inhibitor can be used. Because of this large number of possible interactions, the doctor prescribing the cholinesterase inhibitor should be aware of all other drugs and substances that the patient is taking.
- An important interaction is when a beta-blocker is taken at the same time. Both drugs slow down the heartbeat and in combination can lead to a life-threatening cardiac arrhythmia (AV block). – Patients who use a spray to dilate the bronchial tubes (for example in asthma) also have to fear an interaction, as the mechanism of action of the cholinersterase inhibitor is opposite to that of the spray.
- In addition to this and other direct interactions at individual organs, many other drugs (possibly also herbal preparations!) can have an influence on the metabolism of the cholinesterase inhibitor. – On the one hand, the breakdown of the active substance in the liver can be inhibited, thus increasing the effect. On the other hand, the degradation may also be accelerated so that the interaction does not have a sufficient effect.
