Clozapine: how it works, precautions and adverse effects

One of the main drawbacks of traditional antipsychotic medication is the amount of time it takes to work, as well as its possible adverse effects. However, in the 1950s it was first synthesized clozapine, a well-known atypical antipsychotic today.

Throughout this article we will talk about its effectiveness, its way of acting in the body, as well as its advantages and disadvantages, and the precautions that should be taken by those who consume this drug.

• Related article: "Atypical antipsychotics: characteristics and main uses"

What is clozapine?

Clozapine is a benzodiazepine which is included within the group of atypical antipsychotics. The atypical name is attributed to it due to its differences with the rest of ordinary antipsychotics.

These differences lie in the fact that the former cause much less extrapyramidal symptoms Furthermore, they show great effectiveness in treating both the positive and negative symptoms of schizophrenia.

This drug quickly gained fame due to its advantages over other antipsychotics, including its greater effectiveness. However, despite these advantages,

clozapine has a host of unwanted side effects that affect other functions of the body.

Within its particular history, clozapine was withdrawn from the market in the 70s when it was related to a series of cases of death due to agranulocytosis in people taking this drug. However, approximately ten years after its withdrawal and due to its high efficacy, clozapine returned to the market. with the obligation that the manufacturer carried out hematological controls in order to detect any dangerous side effects.

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In what disorders is it used?

Due to its toxicity, the administration of clozapine is restricted only to schizophrenia resistant to the rest of the antipsychotics, as well as more severe schizophrenia with significant extrapyramidal symptoms or suicide attempts and self harm.

What's more, accompanied by psychological intervention and training in psychosocial skills, clozapine has been established as the reference drug in the treatment of childhood schizophrenia.

Although its use is not recommended in any other case than the treatment of schizophrenia, in very exceptional occasions it is administered in patients who present psychotic symptoms and certain neurological conditions in which psychotic symptoms may also arise.

The form of administration

Clozapine is a medicine that is administered orally in both tablet and oral suspension formats. Normally the recommended dose is one or two doses a day, always at the same time. Nevertheless, It is essential that the patient follow the instructions of his doctor to the letter and ask for advice if you have any doubts that may arise.

Treatment is usually started progressively; starting with low doses until the patient's body accepts the medication. Likewise, the patient must carry out a weekly check-up during the first four months after the start of treatment, after this period the analytics will be carried out once a month.

When the medicine reaches its maximum therapeutic effect a medication adjustment is necessary so that its effects are not exceeded and thus avoid possible unwanted consequences.

Finally, once the therapy has stopped, it is recommended to withdraw clozapine progressively for one or two weeks. When the withdrawal of the drug must be done immediately, due to some pathology such as leukopenia or decrease in the number of leukocytes in the blood, an exhaustive follow-up of the symptoms of the patient.

What precautions should the patient take?

First of all, it is necessary to make sure that the patient is not allergic to clozapine or any of the compounds it contains. Likewise, the patient should inform their doctor if they take any medication, vitamin supplement or herbal compounds, especially in the case of St. John's wort.

On the other hand, there are a number of special conditions that must be taken into account before the administration of clozapine. These conditions are related to a number of conditions and syndromes that may be incompatible with this drug.

1. Heart failure

Patients with serious cardiovascular conditions should take special care when taking clozapine, since they can cause hypotension caused by hemodynamic changes.

2. Diabetes

Clozapine may alter blood glucose levels, so that diabetic people should have a particular control.

3. Chronic respiratory conditions

All those patients who consume clozapine who suffer from asthma or obstructive pulmonary disease should know that this medication can promote the appearance of depressant effects on respiratory function.

4. Epilepsy

Neuropathic-type medications can lower the seizure threshold, causing a risk of seizures.

• Related article: "Epilepsy: definition, causes, diagnosis and treatment"

5. Depression

Clozapine is characterized by exerting a depressant effect on the central nervous system, therefore people with depression should pay special attention to their symptoms.

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6. Liver failure

Most of clozapine is metabolized by the liver. Therefore, it is advisable adjust doses to the level of liver function.

8. Parkinsonism

Although the incidence of clozapine effects on extrapyramidal effects is a much less than with other types of antipsychotics, it can potentiate them, thus aggravating the disease.

6. Constipation

The anticholinergic action of clozapine can cause complications in constipation, causing intestinal obstruction and paralytic ileus.

Other risks

In addition to promoting health disorders that are already present before taking the drug. For example, clozapine can increase photosensitivity, so it is advisable to avoid continuous exposure to the sun.

What's more, you are at risk of neuroleptic malignant syndrome, a life-threatening condition related to antipsychotic use. If the person notices symptoms such as fever, tachycardia or altered consciousness, without a justifiable cause, drug therapy should be discontinued.

Finally, it is totally inadvisable when driving or driving heavy or dangerous machinery due to the possible appearance of drowsiness or dizziness. In the same way, those people who are usually exposed to high temperatures on a regular basis, should also pay special attention, since clozapine can cause heat stroke or hypothermia, due to the elimination of the regulation hypothalamic.

• Related article: "Neuroleptic malignant syndrome: symptoms, causes and treatment"

What side effects can appear?

Among the unwanted side effects associated with clozapine we can find those that appear frequently, the infrequent and those that appear rarely.

Frequent side effects

• Dizziness.
• Feeling sleepy
• Tachycardia.
• Hypotension
• Constipation.
• Weight gain.
• Gastrointestinal disorders.
• Urinary incontinence

Infrequent effects

• Disorientation.
• Insomnia.
• Feeling tired.
• Tremors
• Headache.
• Seizures.
• Nightmares.
• Hypertension and hypotension.
• Leukopenia
• Hyperhidrosis.
• Myoclonic tics.

Rare side effects

• Myocardial infarction.
• Impotence.
• Arrhythmias.
• Granulocytopenia
• Thrombocytopenia
• Increase in blood glucose levels.
• Pulmonary embolisms.
• Glaucoma.