Clozapine: uses, side effects & brands

Written & medically reviewed by Dr. Sanjay Anbu, MBBS · Last reviewed 5 November 2026

Clozapine is used for treatment-resistant schizophrenia, with regular blood monitoring. It belongs to the Antipsychotic (extra) group. More medicines for psychosis, severe agitation and treatment-resistant mental illness.

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Drug type — dosing is set by your doctor

Measure	Range
Drug class	Antipsychotic (extra)
Type	Prescription
Dose	Individual — ask your doctor or pharmacist

What it is used for

Schizophrenia that has not responded to other medicines
Reducing suicide risk in schizophrenia
Psychosis in Parkinson disease (some cases)

Common brand names

India: Sizopin, Lozapin, Clozamed
Worldwide: Clozaril, Versacloz

Common side effects

Drowsiness
Drooling at night
Weight gain and raised sugar
Constipation

Before taking it — precautions

Regular blood counts are compulsory because it can dangerously lower white cells
Tell your doctor if you start or stop smoking; it changes blood levels
Mention heart disease, seizures, diabetes or bowel problems

When to see a doctor urgently

Fever, sore throat or mouth ulcers (low white cells) (urgent)
Severe constipation or swollen belly (urgent)
Chest pain, breathlessness or fast heartbeat (heart inflammation) (urgent)

Not a prescription — no dose shown. The right dose of clozapine depends on age, weight, kidney/liver function and the condition, so MedDroid does not show a dose here. Always get your dose from a doctor or pharmacist and the leaflet inside the pack. General educational information only.

Frequently asked questions

Why do I need so many blood tests?

Clozapine can rarely stop the body making white blood cells, which fight infection. Regular tests catch this early.

Why is constipation taken so seriously?

Clozapine can slow the gut so much that it becomes blocked, which can be life-threatening. Report constipation early.

What if I miss doses for a few days?

Do not restart at your usual dose; contact your doctor, because it may need to be built up again slowly.

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Sources & further reading

Reviewed by Dr. Sanjay Anbu, MBBS. MedDroid is an AI medical assistant and can make mistakes. It provides general health information, not a diagnosis or medical advice — always consult a qualified clinician. In an emergency, contact your local emergency number immediately.