Throughout history, many drugs have been developed to combat the symptoms and alterations caused by many disorders and alterations of the psyche. Antidepressants and anxiolytics are unfortunately not uncommon, given the high prevalence of the problems they treat.

Another problem, highly known and generating a high level of suffering, is schizophrenia. And fortunately for her there are also drugs that contribute to the treatment of her symptoms. Among them is levomepromazine , which we will talk about next.

What is levomepromazine?

Levomepromazine is a high-potency psychoactive drug classified as antipsychotic or neuroleptic drug , which is part of the phenothiazine chemical family.

As such, levomepromazine is effective in the treatment of the symptoms of schizophrenia and other psychotic disorders, especially in the productive clinical setting such as delusions, hallucinations and agitation.

Within the antipsychotics this substance is part of the so-called typical antipsychotics, classic or first generation.

This subtype of antipsychotic was the first to be synthesized, and they are characterized because they are highly effective in treating positive psychotic symptomatology (read that which introduces elements into the subject’s psychic functioning, such as the aforementioned hallucinations or delusions) despite the fact that they unfortunately produce annoying and even in some cases dangerous secondary symptoms.

Moreover, have no effect on and can even worsen negative symptoms , or those characterized by the deterioration or loss of functionalities previously present: impoverishment of language, abulia and emotional flattening and impoverishment of thought or alogia.

Levomepromazine has a sedative and tranquilizing action, as well as an analgesic, and is one of the oldest antipsychotics. It also has antihistamine and antispasmodic properties . It is absorbed in the intestine, metabolized mainly in the liver, and excreted through the urine.

It can be found in different presentations including tablets and drops for oral administration or as injectables for intravenous administration. One of the main commercial brands is Sinogan.

Mechanism of action

Levomepromazine acts in our brain by altering the chemistry of the body, causing an effect on the levels of neurotransmitters that our neurons emit.

Specifically, the action of this drug is produced because we are dealing with a dopamine antagonist , which blocks the D2 receptors of the brain’s neurons in such a way that the neurons stop capturing it to a great extent and their levels are reduced.

This is very useful in the treatment of agitation and positive symptoms, since it has been seen that in schizophrenia there is an excess of dopamine in the mesolimbic pathway of the brain and that this excess is linked to the appearance of agitation, hallucinations and delusions .

However, the performance of this drug and that of the other classical neuroleptics is non-specific, so that they also decrease the levels of dopamine in brain areas that do not have any excess of dopamine or that may even have a deficit (something that occurs precisely in the mesolimbic pathway when there are negative symptoms), so that secondary symptoms such as the motor or sexual ones mentioned above may appear.

In addition, it also alters the levels of histamine, adrenaline and acetylcholine , which can also cause harmful side symptoms.

Main medical uses

As one of the typical antipsychotics it is, levomepromazine has as its main indication the treatment of all those conditions in which psychotic symptoms occur. Its most relevant indications are therefore schizophrenia, acute psychoses and paranoid states . But schizophrenia and psychotic disorders are not the only indications for this drug.

It also has an important effect on algae or pain sensitivity, being a powerful analgesic that allows to treat pain of moderate to severe intensities of different conditions.

In this sense, another of its most relevant indications is in palliative care , specifically in those patients who are in the terminal phase. Levomepromazine helps to treat agitation, delirium and states of confusion and nervousness in these patients, especially when they are associated with pain.

It has even been used in some states of anxiety, depression, bipolar episode or obsessive compulsive disorder, although nowadays there are many drugs much safer and useful for these conditions.

Side effects

Although effective in treating a variety of conditions, levomepromazine can have really annoying or even dangerous side effects (although these are less common).

Among the most common we can find sleepiness or weight gain . Other less frequent side effects may be hyperglycemia and modification of glucose tolerance, provoking tardive dyskinesia or involuntary repetitive movements, generally of a masticatory type. It may lead to sexual dysfunction such as erectile dysfunction or loss of libido, as well as hyperprolactinemia.

In some cases it also favors breast growth in men or lack of menstruation. Hyperglycemia or hyponatremia (low blood sodium levels), as well as alterations in antidiuretic hormone, may be possible. Also seizures and Parkinson’s symptoms.

Some more dangerous reactions may include possible pulmonary embolisms, thrombosis, jaundice, agranulocytosis or leukopenia (these two conditions involving the decrease in the levels of essential elements of the blood, respectively granulocytes and leukocytes).

It can lead to liver damage, heart rhythm disturbances such as arrhythmias, bradycardia or tachycardia, enterocolitis (life-threatening) or the potentially fatal neuroleptic malignant syndrome.

Contraindications

The adverse effects and the alteration that levomepromazine generates in the organism can become dangerous for some sectors of the population, which will have contraindications for this drug.

Firstly, it should be noted that this drug is contraindicated for those who have or have had an allergy to it or any of its components.

Pregnant and lactating women should also avoid it , or at least consult their doctor about the suitability of taking it or changing their medication if necessary.

It is contraindicated in patients with glaucoma, Parkinson’s or porphyria. Its administration should be avoided or consulted with other drugs (especially if levodopa is consumed), and its consumption with alcohol is contraindicated.

It is contraindicated or the condition of patients who have had cardiovascular, renal or hepatic alterations should be monitored (especially if renal or hepatic failure has been reached).

It is also not recommended in diabetic patients (as it affects the blood sugar level) or subjects with problems such as thrombosis or embolism. Epileptic patients should be monitored and controlled given the risk of generating new seizures or reducing the activation threshold that generates the seizures.

It should be avoided in the elderly, especially if they have any kind of dementia, because it may increase the likelihood of premature death.

Bibliographic references:

  • Spanish Agency for Medicines and Healthcare Products (2018). Leaflet: information for the patient. Sinogan 40 mg/ml oral drops in solution. Ministry of Health, Social Policy and Equality,