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

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

What is Clozapine?

Clozapine is a benzodiazepine that is included in the group of atypical antipsychotics. The name atypical is attributed to it because of its differences with other ordinary antipsychotics.

These differences lie in the fact that the former cause far fewer extrapyramidal symptoms and also show great effectiveness in treating both the positive and negative symptoms of schizophrenia.

This drug quickly became famous because of its advantages over other antipsychotics, including its greater effectiveness. Despite these advantages, however, clozapine has a number of unwanted side effects that affect other functions of the body.

In its own unique history, clozapine was withdrawn from the market in the 1970s when it was linked to a series of deaths from agranulocytosis in people taking the drug. However, approximately ten years after its withdrawal and due to its high efficacy, clozapine was reinstated on the market with a requirement for the manufacturer to perform blood tests to detect any dangerous side effects.

In what disorders is it used?

Due to its toxicity, clozapine administration is restricted to schizophrenias resistant to other antipsychotics, as well as to more severe schizophrenias with significant extrapyramidal symptoms or with suicide attempts and self-harm.

Furthermore, 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 , on 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 drug that is given orally in both tablet and oral suspension form. Usually the recommended dose is one or two takes per day, preferably at the same time. However, it is essential that patients follow their doctor’s instructions exactly and seek advice if they have any doubts.

Usually, treatment is started progressively; starting with low doses until the patient’s body admits the medication. Likewise, the patient must keep a weekly control during the first four months after the beginning of the treatment, after this period the analysis will be done once a month.

When the medication reaches its maximum therapeutic effect it is necessary to adjust the medication so that it does not exceed its effects and thus avoid possible unwanted consequences.

Finally, when therapy stops, it is recommended that clozapine be gradually withdrawn over one or two weeks. When the withdrawal of the drug must be done immediately, due to a pathology such as leukopenia or a decrease in the number of leukocytes in the blood, it is essential to closely monitor the patient’s symptoms.

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. Also, the patient should inform their doctor if they are taking any medication, vitamin supplements or herbal compounds, especially in the case of St. John’s wort.

In addition, there are a number of special conditions that must be taken into account before 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 severe cardiovascular conditions should be especially careful if taking clozapine, as may cause hypotension caused by hemodynamic changes.

2. Diabetes

Clozapine may alter blood glucose levels , so people with diabetes should be particularly vigilant.

3. Chronic respiratory conditions

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

4. Epilepsy

Medications of the neuropathic type can lower the threshold of seizures, causing a risk of seizures .

5. Depression

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

6. Liver failure

Most clozapine is metabolized by the liver. It is therefore advisable to adjust the doses to the level of liver function .

8. Parkinsonism

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

6. Constipation

The anticholinergic action of clozapine can cause complications in constipation, leading to 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.

In addition, there is a risk of neuroleptic malignant syndrome , a life-threatening condition related to the use of antipsychotics. If the person experiences symptoms such as fever, tachycardia, or altered consciousness, without a justifiable cause, drug therapy should be discontinued.

Finally, it is totally inadvisable to drive heavy or dangerous machinery due to the possible appearance of drowsiness or dizziness. Similarly, those who are usually exposed to high temperatures should also pay special attention, since clozapine can cause heat stroke or hypothermia, due to the elimination of hypothalamic regulation.

What side effects can occur?

Among the unwanted side effects associated with clozapine we can find those that appear frequently, those that are rare and those that appear on rare occasions.

Common side effects

  • Dizziness .
  • Sleepy feeling.
  • He’s tachycardic.
  • Hypotension.
  • Constipation.
  • Weight gain .
  • Gastrointestinal problems.
  • Urinary incontinence.

Rare 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.
  • Increased blood glucose levels
  • Pulmonary embolisms .
  • Glaucoma.