Sensipin

Indications

Clozapine is used to treat schizophrenia in people whose illness has not improved with at least two other antipsychotic medicines, or who cannot tolerate them because of severe side effects. It is also used to reduce the risk of suicidal behaviour in schizophrenia, and sometimes for psychosis in Parkinson's disease when other treatments are not suitable.

How It Works

Clozapine is an atypical antipsychotic. It acts on several chemical messenger systems in the brain, blocking dopamine and serotonin receptors in a balanced way. This reduces symptoms such as hallucinations, delusions and disordered thinking, and can also help withdrawal and low motivation. It causes fewer movement side effects than many older antipsychotics.

Dosage and Administration

Clozapine is started only by a specialist, at a very low dose, and increased slowly over several weeks, so it must be taken exactly as prescribed. Regular blood tests are required before and throughout treatment. If you miss doses for more than 2 days, do not restart at your usual dose; contact your doctor, as treatment may need to be restarted at a low dose. Do not stop suddenly.

Interactions

• Medicines that can lower white blood cells, such as Carbamazepine, Co-trimoxazole and some cancer medicines, must not be used with it.
• Fluvoxamine, Ciprofloxacin and Erythromycin can raise Clozapine levels.
• Smoking lowers Clozapine levels; stopping or starting smoking can change levels a lot, so tell your doctor.
• Benzodiazepines, alcohol and other sedatives add to drowsiness and breathing problems.
• Medicines that prolong the QT interval or cause constipation need care.

Contraindications

• A previous low white cell count or agranulocytosis, or bone marrow disorders.
• Uncontrolled epilepsy.
• Severe heart disease such as myocarditis, or severe liver or kidney disease.
• Paralytic ileus (bowel not moving).
• Alcohol or drug induced psychosis, or severely reduced consciousness.
• Allergy to Clozapine.

Side Effects

Common side effects include drowsiness, drooling, constipation, weight gain, dizziness on standing, fast heartbeat, raised blood sugar and cholesterol, bedwetting and fever in the first weeks. A serious risk is agranulocytosis, a sudden drop in white blood cells that leaves the body unable to fight infection; this is why blood tests are essential. Severe constipation can lead to a dangerous bowel blockage. Inflammation of the heart muscle and seizures can also occur.

Get urgent medical help if you have fever, sore throat, mouth ulcers or other signs of infection; chest pain, breathlessness or a racing heartbeat; severe constipation, stomach pain or vomiting; a seizure; or high fever with stiff muscles and confusion.

Pregnancy and Lactation

Clozapine should be used in pregnancy only if a specialist decides the benefit outweighs the risk; do not stop it on your own. Babies exposed late in pregnancy may have temporary breathing, feeding or movement problems. It passes into breast milk, so breastfeeding is not recommended during treatment.

Precautions and Warnings

• Regular blood counts are required, weekly at first and less often later.
• Report any sign of infection immediately.
• Treat constipation early and drink plenty of fluids.
• Your weight, blood sugar, lipids and heart may be monitored.
• Do not drive or operate machines until you know how it affects you.
• Older people with dementia have a higher risk of stroke and death with antipsychotics.

Overdose

Overdose can cause deep sleepiness or coma, fast heartbeat, low blood pressure, seizures, breathing problems and excess saliva. It can be fatal. Seek emergency medical help immediately.

Therapeutic Class

Atypical antipsychotic.

Storage

Store below 30°C in a dry place, away from light and out of the reach of children.