How do you take Clozapine?

Your doctor will start you on a very low dose — usually half of a 25 mg tablet (12.5 mg) once or twice a day — and slowly increase it over several weeks. The usual effective dose is between 200 mg and 450 mg per day, divided into 2 or 3 doses. You can take it with or without food. Never increase or decrease the dose on your own — always follow your doctor's instructions exactly.

What are the side effects of Clozapine?

Feeling very sleepy or drowsy (especially when starting), drooling or excess saliva especially at night, dizziness when standing up quickly, weight gain and increased appetite, constipation

Who should not take Clozapine?

People who are allergic to clozapine, people with a history of low white blood cell count (agranulocytosis), people with uncontrolled epilepsy, people with severe heart disease or active liver problems, people who cannot commit to the required regular blood tests, and anyone with a bowel obstruction or paralytic ileus.

Prescription

Atypical Antipsychotic

Clozapine

Last reviewed June 2026

Who is this for?

What is this drug?

Clozapine is a strong antipsychotic medicine that works by balancing certain chemicals in the brain (like dopamine and serotonin) to help control thoughts, mood, and behavior. It is known in Nigeria under brand names like Leponex and Xycloza-100.

What is it used for?

Treatment-resistant schizophrenia (severe mental illness where the person hears voicessees things that are not thereor has confused thinking that other medicines have failed to control)reducing the risk of suicidal behavior in people with schizophrenia

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Schizophrenia & Psychosis

How it works

Blocks dopamine D2 receptors and serotonin 5-HT2A receptors in the mesolimbic and mesocortical pathways, reducing psychotic symptoms and suicidal ideation in treatment-resistant schizophrenia. Additionally, antagonizes muscarinic and alpha-adrenergic receptors, contributing to its unique efficacy in patients unresponsive to conventional antipsychotics.

Prescription Required

You need a doctor's prescription to buy this drug.

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What to watch out for

This medicine requires mandatory regular blood tests (usually every week at first, then monthly) to check your white blood cell count — never skip these tests as they can save your life. Only buy from a registered pharmacy with a valid prescription — do not buy from roadside vendors or open markets, as fake versions of this drug can be very dangerous. Do not stop taking clozapine suddenly without your doctor's guidance, as this can cause serious withdrawal symptoms and a return of psychotic episodes.

Common Side Effects

Feeling very sleepy or drowsy (especially when starting)
drooling or excess saliva especially at night
dizziness when standing up quickly
weight gain and increased appetite
constipation

Serious Side Effects

A dangerous drop in white blood cells (signs include sudden fever
sore throat
or mouth ulcers — this can be life-threatening and needs immediate hospital attention)
seizures or convulsions
inflammation of the heart muscle (signs include chest pain
fast heartbeat
difficulty breathing
and unusual tiredness — go to the hospital immediately)

Drug Interactions

Avoid alcohol completely — it increases drowsiness and can cause dangerous drops in blood pressure. Be careful with medicines like tramadol or codeine as combining them with clozapine can cause severe breathing problems. Smoking cigarettes affects how your body processes clozapine — if you start or stop smoking, tell your doctor as your dose may need to change.

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Pregnancy & Breastfeeding Warning

Clozapine is not considered safe during pregnancy or breastfeeding — it can affect the baby, so consult your doctor immediately if you are pregnant, planning to become pregnant, or breastfeeding.

Who Should NOT Take This

People who are allergic to clozapine
people with a history of low white blood cell count (agranulocytosis)
people with uncontrolled epilepsy
people with severe heart disease or active liver problems
people who cannot commit to the required regular blood tests
and anyone with a bowel obstruction or paralytic ileus.

How to Store

Store in a cool, dry place away from direct sunlight and heat — Nigerian weather can be very hot, so avoid storing near windows or in cars. Keep the medicine in its original container, away from moisture, and always keep it out of the reach of children.

For information only — not medical advice. Always talk to a doctor or pharmacist before changing your medication.