Active Ingredients

Levomepromazine – Effect, Application & Risks


Levomepromazine is a drug that has a much wider range of uses than most people suspect or know. Although it is primarily one of the neuroleptics , it has active properties that also allow it to be used in other medical areas. This mainly affects the side effects of this active ingredient, but their benefit is not yet

What is levomepromazine?

Structurally, levomepromazine belongs to the phenothiazines. From a chemical point of view, this is a so-called “tricyclic compound”. The middle ring of this compound is a heterocycle that has a nitrogen atom and also a sulfur atom.

Phenothiazine, which is the drug group of levomepromazine, is the basis for various drugs that are primarily used as neuroleptics. Phenothiazines can have different structures, so they are divided into three groups:

1. the aliphatic phenothiazines,

2. Piperidines and

3. the piperazines.

Levomepromazine is a low-potency neuroleptic. Like all other relevant phenothiazine derivatives, levomepromazine also has a special property that is used in medicine alongside its original application.

Normally, levomepromazine makes you very tired if the patient does not have a paradoxical reaction to taking it. Therefore, levomepromazine is also often prescribed as a medication to induce sleep in the case of problems falling asleep and sleeping through the night , but also for calming down.

Pharmacological action

Levomepromazine is a phenothiazine of the tricyclic type and, medically speaking, belongs to the group of low-potency neuroleptics. They block the user’s dopamine receptors. These are located in the presynaptic and postsynaptic areas as well as directly on the cell bodies.

However, there is not just a single dopamine receptor, but a whole group of different receptors that take care of processing the dopamine-dependent impulses. These dopamine receptors are roughly divided into D1 and D2 receptors. Levomepromazine acts primarily on the D2 receptors and is therefore referred to as a dopamine antagonist. Above all, it addresses the postsynaptic receptors in the mesolymbic cerebral cortex by blocking them and thus dampening the effect of the body’s own messenger substance dopamine.

Levomepromazine is a low-potency neuroleptic with only a mild antipsychotic effect. However, the strongly sedating component is used as a therapeutic effect when used. The weak effect against psychoses cannot be achieved with higher dosages either. This only accumulates the undesirable side effects in this case, since the higher dosage also stimulates those receptors that were not originally intended to be addressed.

Medical Application & Use

Levomepromazine belongs to the phenothiazines and is a low-potency neuroleptic. It is mainly used as a medication to treat anxiety disorders , restlessness and agitation.

It is also prescribed as a sleep-inducing drug for sleep disorders , as it has a strong sedating component. It is also used as a concomitant medication for chronic pain . Neuroleptics are mainly used in schizophrenia therapy because they have the property of having an antipsychotic and sedative effect.

However, the antipsychotic effect of levomepromazine is too weak, which makes it unsuitable as a sole medication in the treatment of psychoses . For such clinical pictures there are neuroleptics with a stronger antipsychotic effect. Neuroleptics are divided into two generations based on their different mechanisms of action. Levomepromazine belongs to the 1st generation together with promethazine.

Levomepromazine may be known as a drug with the trade name “Neurocil”. Promethazine is usually marketed under the name Atosil®. Even if both drugs are among the low-potency neuroleptics of the 1st generation, they are not exclusively used in medicine in an equivalent way, since the two drugs differ in certain mechanisms of action.

In addition to the treatment of mental illnesses and their effects, levomepromazine is not only used as a sleeping pill , but also in the treatment of chronic and acute allergies , since, like promethazine , it is not one of the low-potency neuroleptics, but also an antihistamine. Therefore, it can be used in certain doses as a remedy for nausea .

Risks & side effects

Even in therapeutic doses, like most drugs, levomepromazine unfortunately does not only have positive and expressly desired effects.

It must also be considered that the receptors that are to be specifically addressed and influenced with this drug have an individual sensitivity in each person. This applies in particular to the use of medications that affect processes and chemical processes in the brain . Undesirable effects can have fatal effects on the vital functions and behavior of the user, especially here. A major risk is the danger that the patient will have a paradoxical reaction to levomepromazine.

This means that an existing restlessness, fear or excitement is massively increased or only caused at all if it is used, for example, due to its antiimetic effect against nausea or as an antihistamine for allergies . Of course, the risk of side effects also increases depending on the dosage. An overdose, whether intentional or unintentional, can have far-reaching consequences.

Restlessness and excitement are likely to be the more harmless consequences. Even a slight overdose can make the user, depending on the sensitivity of his receptors, subject to intensive care because, for example, massive cardiac arrhythmias and respiratory depression can be triggered. As with any other drug, there is of course also the risk of absolute intolerance, which can cause allergic reactions up to and including allergic shock.

Lisa Newlon
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Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.