Haloperidol (antipsychotic): Uses, Effects And Risks
Diazepam, lorazepam, olanzapine, methylphenidate … Some of these names may be very familiar to read and hear in today’s society.
All of them are psychotropic drugs, substances that through certain mechanisms of action combat a series of specific symptoms such as anxiety, depression or hallucinations. They are used in many cases as the treatment of choice or as a first step to control the symptoms of a disorder to be treated through therapy, as a way to keep symptoms under control or as a reinforcer of the effects of psychological therapy.
In this article we are going to talk about one of the psychotropic drugs mainly used in the treatment of psychotic symptoms, haloperidol.
Haloperidol is a typical neuroleptic or antipsychotic included in the group of butyrophenones , depressant agents of the central nervous system with a sedative effect and that act as very powerful antagonists of brain dopaminergic receptors. That means they prevent certain neurons from absorbing the neurotransmitter known as dopamine.
Haloperidol causes powerful motor sedation, which is useful in reducing symptoms of motor agitation and even in cases of pain.
This medication is mainly used for the treatment of schizophrenia and its positive symptoms, these being understood as those that could be considered something that alters and excites the patient, added to the content of his thought, speech or behavior: hallucinations, delusions, agitation, acceleration or distracted, verbose and shallow speech. Haloperidol, however, like most conventional antipsychotics, does not have major effects on negative symptoms (those that “take away” something from the patient, causing slowness, poverty of speech, anhedonia or lack of logic).
Mechanism of action
Haloperidol acts by blocking dopamine receptors in the mesolimbic pathway, specifically type D2 receptors, a fact that involves the suppression of positive symptoms (especially hallucinations and delusions) by reducing excess dopamine in this brain system.
However, haloperidol has a non-specific action, that is, it does not only block the receptors of the mesolimbic pathway but has an effect on other pathways, which can cause unwanted side effects.
Side effects and risks
Like most psychotropic drugs, haloperidol has a series of side symptoms or possible adverse effects. Likewise, like most typical antipsychotics, the effect of action on dopamine blockade has possible repercussions on different systems.
Specifically, its action on the nigrostriatal circuit causes effects related to movement such as slowness, incoordination, muscle hypertonia or rigidity, or even tremors and restlessness Thus, it is possible that a bad reaction to this medication could cause extrapyramidal syndrome, causing the previous symptoms along with gestural inexpression, a static attitude, speaking and writing difficulties, and lack of reflexes. It is possible to control these symptoms with antiparkinsonian drugs. In addition, it can cause akathisia or constant motor restlessness, akinesia or lack of movement and tardive dyskinesias, involuntary movements of the facial muscles that imitate grimaces and chewing gestures, among others.
At the tuberoinfubular level, where haloperidol also acts despite the fact that there is no alteration in psychotic episodes in this pathway, it increases the production of prolactin, which affects the reproductive system and can cause gynecomastia (breast growth in men), galactorrhea or emission of milk from the breasts (even in men) and the absence of menstruation or amenorrhea.
Apart from this, its powerful sedative effect can cause rejection by patients since it decreases the level of consciousness and therefore sometimes flattens affect and personal abilities.
Neuroleptic Malignant Syndrome
Although it is very rare, The possible side effect that can entail the greatest danger is Neuroleptic Malignant Syndrome This very serious condition usually occurs shortly after starting treatment with the drug. It causes muscle rigidity, high fever, tachycardia, arrhythmia and can cause death in 20% of cases. For reasons like this, it is essential to correctly grade the administration of antipsychotics.
Pros and cons of its use
Although these antipsychotics usually have greater side effects than the atypical ones, given that the latter only act at the mesolimbic-mesocortical level while the typical ones such as haloperidol also affect the nigrostriatal system, they continue to be applied in cases with resistance to atypical neuroleptics. As already mentioned, its function is based on the treatment of positive symptoms, causing little improvement in negative symptoms
It should be remembered that these are possible side effects, which do not have to occur but which must be evaluated and which may cause a change in medication. However, haloperidol has a very powerful action that can make it very useful for controlling certain symptoms, and can be used both in psychotic disorders such as schizophrenia and in other problems and conditions.
Other indications
Apart from its application in schizophrenia, haloperidol can be used in a large number of problems due to its diverse properties. This medicine It is very useful in the treatment of acute psychoses and other psychiatric disorders
Due to its sedative properties, it has been used on occasions when the usual therapies have no effect on cases of severe anxiety. It has also been occasionally used as an anesthetic and even to treat chronic pain. Likewise, it is used as a sedative in states of great motor agitation, such as in cases of manic episodes or delirium tremens.
It also serves as an antiemetic, that is, as a mechanism to prevent vomiting in those cases or syndromes in which the cessation of the vomiting process is necessary.
It is also used to treat tics, Tourette syndrome, stuttering or Huntington’s chorea in order to control involuntary spasmodic movements.
Contraindications of haloperidol
Haloperidol is contraindicated during pregnancy It will only be applied in these cases if there are no other alternatives. It is also contraindicated during breastfeeding since it is excreted through breast milk. If the use of haloperidol is necessary, it is necessary to consider the risks and the possibility of not breastfeeding.
Due to its powerful action, haloperidol is not recommended for patients who have to take a car or motorcycle, since sedation and decreased mental alertness can have serious repercussions on driving ability.
Its potency also makes it not recommended in cases with liver or kidney failure. Likewise, it can have serious repercussions if mixed with barbiturates, analgesics, morphine, antihistamines or benzodiazepines, among others.
Likewise, in patients with hypersensitivity to antipsychotics, cases of coma or depression of the nervous system due to the consumption of alcohol and other drugs or patients with previous lesions in the basal ganglia, it is also contraindicated, and its effects may be harmful.
Medication taking schedule
Taking haloperidol, as well as any antipsychotic, must be regulated with great precision in order to avoid or minimize the existence of dangerous secondary symptoms. Although the dose in question will depend on the problem to be treated, the general guideline will be the following:
In acute phases of the disorder, a certain dose is recommended, powerful enough to control the symptoms repeating the same dose until the outbreak or symptoms subside.
It is advisable to wait about six weeks in order to determine if the medication has the expected effects, being able to change to another antipsychotic if not.
Once the acute phase of the disorder has ended, the dose applied will be reduced as the symptoms disappear until a maintenance dose is reached, which is recommended to be maintained in order to avoid relapses.
In the case of patients who are resistant to taking medication due to poor awareness of the disease, a depot presentation of haloperidol can be applied, introducing a preparation that is injected intramuscularly, producing a slow release of the medication.
