Loxapine: Uses and Side Effects of This Drug

The schizophrenia It is one of the types of psychic alteration best known by 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 to those who suffer it since it hinders their relationship with reality and with the world.

Now, fortunately there are treatments that, although they do not cure the condition, do allow 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.

• Related article: "Types of antipsychotics (or neuroleptics)"

What is loxapine?

Loxapine is a psychoactive drug that is part of the group of antipsychotics or neuroleptics

, which through the alteration of brain chemistry allow to reduce or prevent the appearance of psychotic outbreaks and of a large part of the symptoms of the schizophrenia and the rest of psychotic disorders.

It is one of the antipsychotics known as typical or first generation, which have been found to be highly effective for combat symptoms such as hallucinations, delusions, agitation and restlessness, brain drain, 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 normal functioning of the subject).

However, it must be borne in mind that symptoms such as poverty of thought or speech, allegiance or apathy, known as symptoms negative (since they subtract the capabilities of the subject), they are not reduced by this type of drug and a worsening could even appear in this sense. This is why and because of the fact that typical neuroleptics can generate serious side effects that have developed over time. other substances (atypical or second generation), 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 high amounts. small but nevertheless for the same reason can cause side effects with greater ease.

You can find this drug in capsule form, although in recent years a presentation has also been developed in the form of a powder for inhalation (with a much faster effect than in oral presentation). Despite being typical or first generation, its operation sometimes makes some authors have considered it part of the atypical neuroleptics (something that we will comment on in the next pulled apart).

Mechanism of action

The functioning of loxapine on the human organism is produced from 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 make the dopamine of this brain pathway decrease and that its receptors do not use it. However, as we have said before, 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 deficit of dopamine in pathways such as the mesocortical. And typical neuroleptics are nonspecific - they lower whole brain dopamine.

That is why sometimes it is even possible that some antipsychotics make some symptoms worse. negative, or have side effects in areas where dopamine levels were normotypic.

Fortunately, Despite being one of the typical antipsychotics, loxapine also has an antagonistic effect on serotonin 5-HT2A receptors.. Since serotonin acts as a natural dopamine inhibitor and there are a large number of serotonergic receptors in the cortex, the fact of inhibiting it makes them Dopamine areas are not so diminished by the effects on D2 receptors, so that dopamine levels in areas with a deficiency of this are maintained or even increased. This is why loxapine is sometimes said to act as an outlier. It also has some anticholinergic effect.

• You may be interested: "Types of neurotransmitters: functions and classification"

Indications of this drug

As an antipsychotic, loxapine 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 it seems 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 used occasionally to control agitation in some cases of manic episode of bipolar disorder.

Where it is most used is in the treatment of agitation under these conditions, since it has a sedative effect similar to that of haloperidol. However, after the control of 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 it can appear with certain easy annoying or undesirable side effects, in addition to being able to appear (although less frequently) serious problems derived from its consumption.

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. Likewise, hypotension, polyuria, milk secretion or galactorrhea, decreased libido or tardive dyskinesia may also occur. If given by inhalation, they may appear to be irritating to the respiratory tract. Bronchospam or hypoventilation may also appear.

More serious but less frequent may be the appearance of the aforementioned bronchospasms, as well as seizures or the most dangerous leukopenia, agranulocytosis or the always possible neuroleptic malignant syndrome.

Contraindications

Another aspect to keep in mind is that not everyone can take loxapine, since some personal ailments or situations can cause It is contraindicated or at least that when used, great care must be taken to control and monitor the situation and the doses used.

This drug should not be used by people with an allergy to loxapine or any of its components. People who have suffered from seizures, heart problems, glaucoma, or respiratory diseases in the case of the inhaled version (due to the risk of bronchospasm).

Neither people with urinary problems, nor pregnant or lactating women, should use it. People with kidney and liver failure should consult a 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.

Bibliographic references:

• Chakrabarti, A., Bagnall, A.M., Chue, P., Fenton, M., Palaniswamy, V., Wong, W, Xia, J. (2007). Loxapine for schizophrenia. Cochrane Database Syst Rev.; 4.