Meds and you

27 September 2013


Clozapine is an anti-psychotic. Anti-psychotics are drugs that are used to treat psychosis, a state of mind in which thinking becomes irrational and/or disturbed.


Clozapine is the active ingredient of Cloment tablets (Nappi code:700176-001, 700178-001), Clozapine-Hexal tablets (Nappi code:705844-001, 705845-001) & Leponex tablets (Nappi code:736708-006, 736716-009).

General information
Clozapine is an anti-psychotic. Anti-psychotics are drugs that are used to treat psychosis, a state of mind in which thinking becomes irrational and/or disturbed and which may include delusions, hallucinations, and severe thought disturbances.

In South Africa clozapine is registered for the treatment of severe therapy-resistant schizophrenia and associated psychoses.

This medication does not cure the underlying condition, but simply keeps the symptoms under control. For this medication to be effective it has to be taken regularly, even if you do not notice an immediate effect.

Treatment should not be stopped abruptly, especially if you have been taking this drug for a prolonged period of time. To prevent withdrawal symptoms you should decrease your dose gradually only as directed by your doctor.

It should be noted that because this drug may cause dizziness, light-headedness and/or sedation, driving and any hazardous tasks should be avoided until you know how this medication affects you.

How does clozapine work?
Clozapine has an effect on a chemical messenger in the brain called dopamine. Dopamine plays an important role in, amongst others, regulating mood and behavior. Conditions such as schizophrenia and associated psychosis are associated with an over-activity of dopamine in the brain. Clozapine reduces the effect of this chemical in the brain, thereby relieving symptoms.

Fast facts

Drug schedule: schedule 5
Available as: clozapine is available as tablets.
What does it do? Clozapine reduces the occurrence of psychoses, thereby helping patients to re-establish a more normal lifestyle.
Overdose risk: medium
Dependence risk: low
Is clozapine available on prescription only? yes

User information

Onset of effect: it may take several weeks for the full effect of this drug to be seen.
Stopping this medicine: do not stop using this medication abruptly as there is a risk of rebound psychosis. It is advised that you decrease your dose gradually as directed by your doctor - preferably over 7-14 days.
Prolonged use: regular blood and liver-function tests are advised to rule out a decrease in white blood cells. Significant weight gain is also seen in some patients.

Special precautions
Consult your doctor before using this drug if:

  • you have epilepsy

  • you have been diagnosed with a blood or bone-marrow disorder

  • you are under the influence of alcohol

  • you are taking other medication

  • you have liver or kidney disease

  • you have been diagnosed with a cardiovascular disorder

  • you have an enlarged prostate

  • you have glaucoma

  • you have diabetes

  • you are younger than 16 years of age

Pregnancy: avoid. It is unknown how this medication may affect your baby. Consult your doctor before using this drug, or if you are planning to fall pregnant.
Breastfeeding: avoid. This medication is passed through breast milk and may affect your baby adversely. Consult your doctor before use.
Porphyria: avoid. It is unknown how this medication may affect your condition. Consult your doctor before use.
Infants and children: this medication is not intended for use in children under the age of 16 years.
Elderly: caution is advised in the elderly as side effects are more likely to occur
Driving and hazardous work: this medication should be avoided as it may cause extreme sedation.
Alcohol: avoid concomitant use of alcohol with this medication.

Possible side effects

Side Effect
Consult your doctor

Only if severe
In all cases


excessive salvia


involuntary facial and body movements


dry mouth




dizziness with sudden movement




weight gain






visual distrubances


flu-like symptoms




abnormally high temperature



Drug interactions

alcohol enhanced CNS depression
benzodiazepines enhanced CNS depression
antidepressants enhanced CNS depression
antihistamines enhanced CNS depression
lithium enhanced toxicity enhanced
warfarin risk of warfarin toxicity
drugs that suppress bone marrow function risk of increased bone marrow suppression
carbamazepine reduced effect of clozapine
phenytoin reduced effect of clozapine
sodium valproate reduced effect of clozapine
drugs for the treatment of high blood pressure risk of potentiated low blood pressure
ssri antidepressants risk of clozapine toxicity

Disease interactions
Consult your doctor before using this drug if you have epilepsy, a blood or bone-marrow disorder, liver or kidney disease, diabetes, a cardiovascular disorder, an enlarged prostate or if you have glaucoma.

Overdose action
A small overdose is no cause for concern. In case of intentional large overdose seek emergency medical attention.

Recommended dosage
Adults, oral: 200 - 450 mg/day in 2-3 divided doses with a maximum daily dose of 900 mg.

This material is not intended to substitute medical advice, but is for informational purposes only. Please consult a physician for specific treatment and recommendations.

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