Clozapine is used to treat patients with schizophrenia who have failed to respond adequately to the currently used treatment. It helps to relieve symptoms common in schizophrenia, such as distorted thinking and emotional instability. It also helps to reduce the risk of suicidal behaviour in schizophrenia.
Clozapine is also used to treat distorted thinking and emotional instability in Parkinson's disease in cases where the currently used treatment has failed.
Take Clozapine exactly as directed by your doctor or according to the instructions on the label. Do not take more or less than instructed by your doctor.
This medicine may be taken with or without food. Try to take it at the same time each day.
Clozapine is available as conventional tablet, oral disintegrating tablet and suspension.
If you have been given the conventional tablet, swallow it with a glass of water.
If you have been given the oral disintegrating tablet, remove it from the foil only just before you take it. Place the tablet on your tongue and chew or allow it to dissolve. Then, swallow it with your saliva. If you are taking only part of the tablet, throw away the part that is not taken.
If you have been given the suspension, use the oral syringe, dropper, measuring spoon or cup provided to measure out your dose accurately.
Clozapine must be taken regularly for it to be effective. Continue taking this medicine even when you feel better. Do not stop taking it unless instructed otherwise, as stopping it suddenly could worsen your condition.
Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and return to your normal dosing schedule.
DO NOT double a dose under any circumstances.
If you miss more than 2 days of Clozapine, do not restart your medicine. Contact your doctor immediately.
If you often forget to take your medicine, let your doctor and pharmacist know.
Clozapine is not suitable for patients with dementia-related psychosis.
Alert your doctor if you have:
- blood disorders
- epilepsy (fits)
- bowel blockage or bowel paralysis (paralytic ileus) which causes severe constipation
- impaired bone marrow function
- severe heart, liver or kidney disease
- mental illness caused by alcohol or drug addiction
as Clozapine may not be suitable for you.
Inform your doctor if you have:
- previous abdominal surgery
- prostate problems or difficulty passing urine
- glaucoma (increased pressure in the eye)
- risk factors for blood clot
- risk factors for stroke
Let your doctor know if you are pregnant or breastfeeding.
If you are going for an operation, including minor operations and dental work, inform your doctor or dentist that you are being treated with Clozapine.
Clozapine may cause your white blood cell count to drop drastically. This may put you at higher risk for infections. For as long as you are being treated with Clozapine, you will need to have regular blood tests done. These blood tests are very important for you. These tests help your doctor to check that your white blood cell counts are within the normal range. Your doctor will advise you about how often you need to have these blood tests.
Clozapine may also cause your blood sugar levels to rise. Monitor your blood sugar levels more regularly if you have diabetes or a family history of diabetes. Ask your doctor how often you need to have your blood sugar levels monitored.
Be very sure to keep all appointments with your doctor.
Clozapine may make you drowsy or dizzy. It can also make your vision blurred. If affected, do not drive or take part in any activity in which you need to be alert. Dizziness may be worse when you get up from a sitting or lying down position, especially if you are taking Clozapine for the first time or if your dose is still being adjusted. This is normal and should disappear gradually as you get used to the medicine. It will help if you get up slowly from a sitting or lying down position.
Clozapine may cause fits or seizures in some people. Do not take part in any activities where a sudden loss of consciousness may be dangerous. Avoid activities such as driving, operating machinery, swimming or climbing.
Other common side effects with Clozapine include headache, constipation, dry mouth, nausea, vomiting, sweating, drooling, difficulty sleeping, difficulty urinating, restlessness, tremor, muscle rigidity, slurred speech and weight gain. Inform your doctor if these side effects become severe or refuse to go away.
Other side effects may need immediate medical help. Alert your doctor immediately if you experience any of the following:
- rapid or irregular heartbeat
- chest pain
- difficulty breathing or wheezing
- severe tiredness or weakness
- fever with persistent sore throat
- uncontrolled muscle movements of your body, face or tongue, such as lip smacking or worm-like movements of the tongue
- rapid rise in your body temperature or an inability to cool down on a hot day
Inform your doctor if any of these side effects do not go away or are severe, or if you experience other side effects.
Inform your doctor and pharmacist if you are taking any of these medicines:
- medicines for anxiety and sleep disorder e.g. diazepam, alprazolam, buspirone
- medicines for mood disorders e.g. risperidone, lithium, fluvoxamine, clomipramine
- medicines to treat depression e.g. citalopram, fluoxetine, paroxetine, sertraline
- medicines for allergy e.g. antihistamines
- medicines for heart disease e.g. quinidine, procainamide, digoxin
- certain antibiotics e.g. ciprofloxacin, erythromycin, ampicillin
- stomach medicines e.g. cimetidine, omeprazole
- medicines for epilepsy (fits) e.g. valproic acid, phenytoin, carbamazepine
This list does not include all medicines that may interact with Clozapine.
Always inform your doctor and pharmacist if you are taking any other medicines, including herbal tonics such as traditional Chinese medicine, supplements and medicines that you buy without a prescription.
Avoid alcohol. Alcohol will worsen the dizziness and drowsiness caused by Clozapine.
Store in a cool, dry place away from the reach of children.
Medicines must not be used past the expiry date.