Schizophrenia is one of the types of psychic disturbance best known to most of the population, in part due to some of its most visible and striking typical symptoms: hallucinations and delusions. However, this disorder can present many more symptoms, and generates great suffering for those who suffer from it since it makes their relationship with reality and the world difficult.
Now, fortunately there are treatments that, although they do not cure the condition, they do allow you to control and prevent its symptoms and therefore lead a normative life. One of the most relevant aspects of the treatment of this disorder is the use of drugs that are very useful in controlling symptoms. And although within the available drugs we can find a great variety of substances, An example of them is found in loxapine, which we will talk about below
Loxapine is a psychotropic drug that is part of the group of antipsychotics or neuroleptics which through the alteration of brain chemistry make it possible to reduce or prevent the appearance of psychotic outbreaks and a large part of the symptoms of schizophrenia and other psychotic disorders.
It is one of the antipsychotics known as typical or first generation, which have been observed to be highly effective for combat symptoms such as hallucinations, delusions, agitation and restlessness, flight of ideas, derailments tension or erratic behavior (the so-called positive symptoms, not because they are good but because they add some characteristic or element to the subject’s usual functioning).
However, it must be taken into account that symptoms such as poverty of thought or speech, alogia or apathy, known as negative symptoms (since they reduce the subject’s capabilities), are not reduced by this type of drug and could even appear. a worsening in this sense. It is for this reason and for the fact that typical neuroleptics can generate serious side effects that other substances (atypical or second generation) have developed over time, although loxapine and other typical antipsychotics continue to be applied in some cases.
loxapine It is chemically a dibenzoxazepine It is considered a high-potency drug, which has relevant effects with relatively small quantities but which, for this same reason, can cause it to generate side effects more easily.
It is possible to find this drug in capsule form, although in recent years a powder form for inhalation has also been developed (with a much faster effect than in oral presentation). Despite being typical or first generation, its functioning means that some authors have sometimes considered it part of the atypical neuroleptics (something we will discuss in the next section).
Mechanism of action
The functioning of loxapine on the human body occurs through a mechanism of action based on the blockade of dopamine D2 receptors. In schizophrenia and other psychotic disorders, the existence of an excess of dopamine in a specific brain pathway, the mesolimbic pathway The fact that this excess exists is linked to the appearance of positive symptoms, and specifically the most florid and striking: hallucinations, delusions and agitation among others.
In this sense, loxapine and the rest of the typical antipsychotics are very useful, since they cause the dopamine in this brain pathway to decrease and its receptors do not use it. Now, as we have said previously, this would not have a beneficial effect on negative symptoms. This is because this type of symptoms is linked not to an excess, but to a deficiency of dopamine in pathways such as the mesocortical. And typical neuroleptics are nonspecific: They reduce dopamine throughout the brain.
This is why it is sometimes even possible for some antipsychotics to worsen some negative symptoms, or to generate side effects in areas where dopamine levels were normotypical.
Fortunately, Despite belonging to the typical antipsychotics, loxapine also has an antagonistic effect on serotonin 5-HT2A receptors Given that serotonin acts as a natural inhibitor of dopamine and in the cortex there are a large number of serotonergic receptors, the fact of inhibiting it means that in these areas dopamine is not so diminished due to the effects on the D2 receptors, so that dopamine levels in areas with a lack of dopamine are maintained or even increased. This is why loxapine is sometimes said to act as an atypical. It also has a certain anticholinergic effect.
Indications of this drug
Loxapine, as an antipsychotic, is mainly indicated for use in cases of schizophrenia and other psychotic disorders. Although its effectiveness is not greater than that of other better-known drugs, There is data that appears to be somewhat more effective on negative symptoms than other typical or first generation antipsychotics. Other substances are usually preferred as the first choice (it is used more when other options do not generate the expected response). In addition to this, it is also occasionally used to control agitation in some cases of manic episode of bipolar disorder.
Where it is most used is in the treatment of agitation in these conditions, since it has a sedative effect similar to that of haloperidol. Now, after controlling these acute episodes, it is necessary to establish the corresponding treatment.
Side effects and risks
Loxapine is a very powerful drug, and although it can be useful, the truth is that its high power means that annoying or undesirable side effects can appear with some ease, in addition to serious problems arising from its consumption (although less frequently).
To begin with, among the most common secondary symptoms we find dysgeusia or distortion of the sense of taste, sedation (which, although desirable in some contexts, can be harmful in others, and even a risk in areas such as driving), dizziness, instability or blurred vision. Hypotension, polyuria, milk secretion or galactorrhea, decreased libido or tardive dyskinesia may also occur. If given by inhalation, irritation may appear in the respiratory tract. Bronchospasm or hypoventilation may also occur.
More serious, although less frequent, may be the appearance of the aforementioned bronchospasms, as well as seizures or the more dangerous leukopenia, agranulocytosis or the always possible neuroleptic malignant syndrome
Contraindications
Another aspect to take into account is that not everyone can consume loxapine, since some ailments or personal situations may make it contraindicated or at least, if used, great care must be taken to control and monitor the situation and the conditions. doses used.
This drug should not be used by people who are allergic to loxapine or any of its components. People who have suffered seizures, heart problems, glaucoma or respiratory diseases in the case of the inhaled version (due to the risk of bronchospasm).
People with urinary problems, or pregnant or lactating women, should not use it either. People with kidney and liver failure should consult with their doctor about the suitability of its use. Finally, in the case of elderly people with dementia it should be avoided, since it has been seen that the use of antipsychotics can increase the risk of mortality.
