Levomepromazine is an active ingredient that offers a much wider range of applications than most people assume or know. Although it belongs primarily to the neuroleptics, it has effect properties that allow its use in other medical areas as well. This is especially true of the side effects of this agent, but its usefulness has not yet been
What is levomepromazine?
Although levomepromazine primarily belongs to neuroleptics, it has effective properties that allow its use in other medical fields as well. Levomepromazine belongs to the phenothiazines in terms of its structure. Chemically, it is a so-called “tricyclic compound”. The middle ring of this compound is a heterocycle, which has a nitrogen atom and also a sulfur atom. Phenothiazine, which is the active group of levomepromazine, is the basis for various drugs, which are primarily used as neuroleptics. Phenothiazines can have different structures, so they are divided into three groups:
1. aliphatic phenothiazines,
2. piperidines, and
3. the piperazines. Levomepromazine is a low-potency neuroleptic. Like all other relevant phenothiazine derivatives, levomepromazine has a special property which is utilized in medicine in addition to its original application. Normally, levomepromazine – should the patient not react paradoxically to the intake – makes very tired. Therefore, levomepromazine is also popularly prescribed as a medication to induce sleep in cases of sleep onset and sleep maintenance disorders, as well as for sedation.
Pharmacological action
Levomepromazine is a tricyclic-type phenothiazine and is medically classified as a low-potency neuroleptic. 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 one dopamine receptor, but a whole group of different receptors that take care of processing the dopamine-dependent impulses. Roughly, these dopamine receptors are divided into D1 – and D2 receptors. Levomepromazine exerts its effect mainly at the D2 receptors and is therefore called a dopamine antagonist. It primarily targets the postsynaptic receptors in the mesolimbic cerebral cortex by blocking them and thus dampening the effect of the endogenous neurotransmitter dopamine. Levomepromazine is a low-potency neuroleptic with only mild antipsychotic effects. However, the strong sedative component is used as a therapeutic effect in its application. The weak effect against psychosis cannot be achieved even by higher dosages. This only cumulates the undesirable side effects in this case, since the higher dosage also stimulates those receptors which were not originally intended to be addressed.
Medical application and use
Levomepromazine belongs to the phenothiazines and is a low-potency neuroleptic. It finds its use mainly as a medication for the treatment of anxiety disorders, restlessness, and in states of agitation. It is also prescribed as a sleep-inducing drug for sleep disorders, as it has a strong sedative component. Furthermore, it is used as an adjunctive medication for chronic pain. Neuroleptics are mainly used in schizophrenia therapy because they have antipsychotic and sedative properties. However, the antipsychotic effect of levomepromazine is too weak, which makes it unsuitable as the sole medication in the treatment of psychoses. For such clinical pictures, there are neuroleptics with stronger antipsychotic effects. Neuroleptics are divided into two generations based on their different mechanisms of action. Levomepromazine, along with promethazine, is categorized as 1st generation. Levomepromazine may be familiar as a drug with the trade name “Neurocil.” Promethazine is usually sold under the name Atosil. Even though both drugs belong to the 1st generation of low-potency neuroleptics, they are not used in medicine in an exclusively equivalent manner, as the two drugs differ in certain mechanisms of action.Levomepromazine is used not only in the treatment of mental illness and its effects as a sleeping pill, but also in the therapy of chronic and acute allergies, because, like promethazine, it does not belong to the group of low-potency neuroleptics, but also to the group of antihistamines. Therefore, in certain dosages, it can be used as an antinausea agent.
Risks and side effects
Levomepromazine, even in therapeutic doses, like most drugs, unfortunately does not have only positive and explicitly desired effects. It must also be remembered that the receptors that are to be targeted and influenced by this drug have an individual sensitivity in each person. This is especially true when using medications that influence processes and chemicals in the brain. Unwanted effects, especially here, can have fatal consequences for the vital functions and behavior of the user. A major risk is that the patient may react paradoxically to levomepromazine. This means that an already existing restlessness, anxiety, or agitation is massively increased or caused in the first place if, for example, it is used as an antihistamine due to its anti-mimetic effect against nausea or in the case of allergies. The risk of side effects also increases, of course, depending on the level of dosage. An overdose, whether intentional or unintentional, can have far-reaching consequences. Restlessness and agitation may still be the more harmless consequences. Even a slight overdose can make the user liable to intensive care, depending on the sensitivity of his receptors, as massive cardiac arrhythmias and respiratory depression can also be triggered, for example. Of course, as with any other drug, there is also the risk of absolute intolerance, which can cause allergic reactions and even allergic shock.
