Clozapin Sandoz 25 mg and 100 mg tablets – clozapine for treatment-resistant schizophrenia

Clozapin Sandoz contains clozapine, an antipsychotic used in treatment-resistant schizophrenia – when at least two other medicines for schizophrenia have not worked or have caused severe side effects that could not be treated. It is also used for severe psychotic disorders in people with Parkinson’s disease in whom other treatment has failed.

In Serbia it is authorised as 25 mg and 100 mg tablets (50 tablets each). Because of the risk of agranulocytosis (a serious drop in white blood cells) and inflammation of the heart muscle, the medicine may only be taken with regular blood count checks and under close medical supervision.

What is Clozapin Sandoz used for and how is treatment carried out safely?

Basic information about the medicine

What is Clozapin Sandoz used for?

• treatment-resistant schizophrenia – when at least two other antipsychotics have not worked or have caused severe side effects
• severe disorders of thinking, emotions and behaviour (psychotic disorders) in people with Parkinson’s disease, when other treatment has failed

How is it taken and dosed?

The dose is increased gradually to reduce the risk of low blood pressure, seizures and sleepiness. Do not change the dose or stop treatment without medical advice.

Swallow the tablet with water. Always take the lowest dose that is effective for you. This is the general dosing from the leaflet – your doctor decides the schedule and dose.

Special patient groups

• Children and adolescents under 16 years: not intended for this group (insufficient data).
• Over 60 years: fainting or light-headedness on changing position, fast heartbeat, difficulty urinating and constipation occur more often – treatment starts at a lower dose and is increased very gradually.
• Liver impairment: used with caution, with regular liver function tests; acute, progressive or severe liver disease is a contraindication.
• Severe kidney disease: must not be used.

Contraindications – when the medicine must not be used

• allergy to clozapine or any of the excipients
• inability to have regular blood count checks
• history of low white blood cell count (leukopenia, agranulocytosis), especially if drug-induced (except after chemotherapy); previous discontinuation of clozapine because of severe side effects
• treatment with depot antipsychotic injections (current or previous); medicines that impair bone marrow function or reduce white blood cells
• bone marrow disease, uncontrolled epilepsy
• acute psychosis caused by alcohol or drugs, impaired consciousness, severe drowsiness, coma, circulatory collapse
• severe kidney disease; myocarditis or other severe heart disease
• jaundice or other severe liver disease
• paralytic ileus (bowels not working, severe constipation)

Warnings and precautions

• Before starting, tell your doctor if you (or family members) have had blood clots, or if you have glaucoma, diabetes, prostate or urination problems, heart, kidney or liver disease, chronic constipation, bowel disease or abdominal surgery, controlled epilepsy, prolonged QT interval (also in the family) or a risk of stroke.
• Tell your doctor immediately, before the next tablet, about: signs of a cold, fever, sore throat or any infection (urgent blood test); a sudden rise in temperature with muscle stiffness (neuroleptic malignant syndrome); a fast or irregular heartbeat at rest, palpitations, breathlessness, chest pain or unusual tiredness; nausea, vomiting or loss of appetite (liver check); marked constipation, abdominal pain or bloating, fever or bloody stools.
• The doctor monitors weight, blood fats and blood sugar; in liver disease liver function tests are done regularly, and an ECG if needed.
• Light-headedness or fainting on standing increase the risk of falls – get up slowly.
• Before surgery or prolonged immobility, talk to your doctor because of the risk of thrombosis.
• The medicine contains lactose; less than 1 mmol sodium per dose (“sodium-free”).

Interactions with other medicines, food and drink

• must not be taken together: medicines that impair bone marrow or reduce white blood cells – carbamazepine, chloramphenicol, sulfonamides (co-trimoxazole), pyrazolone analgesics (phenylbutazone), penicillamine, cytotoxic medicines, depot antipsychotic injections
• antidepressants (lithium, fluvoxamine, tricyclic antidepressants, MAO inhibitors, citalopram, paroxetine, fluoxetine, sertraline), other antipsychotics, benzodiazepines and sleeping medicines, narcotics
• phenytoin, valproic acid; adrenaline and noradrenaline; warfarin; digoxin and antiarrhythmics
• antihistamines, anticholinergics, atropine (eye drops, cough and cold preparations), medicines for Parkinson’s disease
• omeprazole, cimetidine, erythromycin, rifampicin, ketoconazole, HIV protease inhibitors, hormonal contraceptives
• alcohol must not be consumed; tell your doctor if you smoke and how much coffee, tea or cola you drink – sudden changes in smoking or caffeine intake alter the effect of the medicine
• The list is not complete – before any new medicine, including herbal ones, ask your doctor or pharmacist.

Pregnancy and breastfeeding

If you are pregnant, think you may be pregnant or are planning a pregnancy, your doctor will discuss the benefits and risks with you; tell them immediately if you become pregnant during treatment. Newborns of mothers who took the medicine in the last trimester may show trembling, muscle stiffness or weakness, sleepiness, agitation, breathing problems and feeding difficulties. Menstrual cycles may return to normal when switching to clozapine, so adequate contraception is needed. Do not breastfeed during treatment – clozapine passes into breast milk.

Driving and using machines

Clozapin Sandoz has a strong effect on psychophysical abilities – driving and operating machines are not allowed during treatment.

Possible side effects

• Very common: sleepiness, dizziness, increased saliva production, fast heartbeat, constipation (may be extremely severe).
• Common: signs of infection and fever (possible drop in white blood cells), seizures, brief loss of consciousness, weight gain, blurred vision, headache, trembling, stiffness, restlessness, abnormal movements, ECG changes, high blood pressure or drop in blood pressure on standing, nausea, vomiting, loss of appetite, dry mouth, loss of bladder control or urination problems, tiredness, increased sweating, slurred speech.
• Uncommon: agranulocytosis, neuroleptic malignant syndrome, light-headedness or fainting on standing, stuttering.
• Rare: pneumonia, pancreatitis, circulatory collapse, difficulty swallowing, liver disease, rapid weight gain, pauses in breathing during sleep, myocarditis or pericarditis, anaemia, delirium, raised blood sugar and diabetes, blood clot in the lungs.
• Very rare and not known: priapism, bleeding due to low platelets, bowel obstruction and other severe bowel complications, severe liver damage, kidney inflammation, cardiomyopathy, cardiac arrest, heart attack, atrial fibrillation, sepsis, rhabdomyolysis, systemic lupus, restless legs syndrome.

Report any suspected side effects to your doctor, pharmacist or ALIMS (Medicines and Medical Devices Agency of Serbia).

Overdose, missed dose and stopping treatment

• Overdose: tell a doctor immediately or call emergency services. Sleepiness, loss of consciousness, coma, confusion, hallucinations, agitation, seizures, drooling, dilated pupils, low blood pressure, collapse, fast or irregular heartbeat and breathing difficulties may occur.
• Missed dose: take it as soon as you remember; if it is almost time for the next dose, skip the missed one. Do not take a double dose. If you have not taken the medicine for more than 48 hours, seek medical advice immediately – treatment is restarted at 12.5 mg.
• Stopping treatment: do not stop without your doctor – sweating, headache, nausea, vomiting and diarrhoea, as well as return of symptoms, may occur. The dose is reduced gradually, by 12.5 mg steps over 1–2 weeks; abrupt stopping only under medical supervision.

Composition, pack and manufacturer

• Active substance: clozapine 25 mg or 100 mg per tablet.
• Excipients: lactose monohydrate; maize starch; colloidal anhydrous silica; sodium lauryl sulfate; povidone (K25); microcrystalline cellulose; sodium starch glycolate (type A); magnesium stearate.
• Pack: 25 mg – carton with 2 PVC/Al or PP/Al blisters of 25 tablets; 100 mg – carton with 5 blisters of 10 tablets (50 tablets in total).
• Marketing authorisation holder: Sandoz Pharmaceuticals d.d. Representative Office Belgrade, Kneginje Zorke 2, Belgrade.

Storage

• This medicine does not require any special storage conditions.
• Keep out of the sight and reach of children.
• Do not use after the expiry date stated on the pack (shelf life: 3 years).

Frequently asked questions

Why are blood counts checked so often during clozapine treatment?

Clozapine can cause agranulocytosis – a serious drop in the white blood cells that defend the body against infection. Only regular tests (weekly for the first 18 weeks, then at least monthly and for 4 weeks after stopping) can detect this risk in time.

What should I do if I get a fever or sore throat?

Contact your doctor immediately, before taking the next tablet – an urgent blood test will be needed to check whether the symptoms are related to clozapine.

Why is constipation so important with clozapine?

Constipation is a very common side effect and can progress to dangerous bowel obstruction. Marked constipation, abdominal pain or bloating should be reported to your doctor immediately.

What if I have missed my medicine for more than two days?

If you have not taken the medicine for more than 48 hours, do not simply continue at your previous dose – seek medical advice immediately. Treatment is then restarted at 12.5 mg and increased gradually.

Sources

• ALIMS – Summary of Product Characteristics Clozapin Sandoz® 25 mg and 100 mg, tablets (Serbian)
• ALIMS – Patient leaflet Clozapin Sandoz® 25 mg and 100 mg, tablets (February 2022, Serbian)

Date sources were checked: 24 October 2026.