Brand name Clozaril
Used in the following combined preparations None
GENERAL INFORMATION
Clozapine is a new type of antipsychotic drug that is used to treat schizophrenia. It is prescribed only for patients who have not responded to other treatments or those patients who have experienced intolerable side effects with other drugs. Clozapine helps control severe resistant schizophrenia, helping the patient to re- establish a more normal lifestyle. The improvement is
gradual, and relief of severe symptoms can take more than three weeks.
All treatment is started and supervised by a hospital, because all patients must be registered with the Clozaril Patient Monitoring Service (CPMS). The drug can cause a very serious side effect, agranulocytosis (a large decrease in the number of white blood cells). Blood tests are done before treatment and regularly thereafter; the drug is supplied only if results are normal.
Clozapine is less likely than other antipsychotics to cause parkinsonism.
INFORMATION FOR USERS
This drug is given only under strict medical supervision and continual monitoring.
How taken
Tablets.
Frequency and timing of doses
1-3 x daily; a larger dose may be given at night.
Adult dosage range
25-900mg daily.
Onset of effect
Gradual. Some effect may appear within 3-5 days, but the full beneficial effect may not be felt for over 3 weeks.
Duration of action
Up to 16 hours.
Diet advice
None.
Storage
Keep in a closed container in a cool, dry place away from the reach of children.
Missed dose
Take as soon as you remember. If your next dose is due within 2 hours, take a single dose now and skip the next.
Stopping the drug
Do not stop the drug without consulting your doctor because symptoms may recur.
Exceeding the dose
An occasional unintentional extra dose is unlikely to cause problems. Large overdoses may cause unusual drowsiness, fits, and agitation. Notify your doctor.
POSSIBLE ADVERSE EFFECTS
Clozapine is less likely to cause parkinsonian side effects (tremor and stiffness) that occur with the use of other antipsychotic drugs. The most serious side effect is agranulocytosis, and strict monitoring is necessary.
INTERACTIONS
Sedatives All drugs that have a sedative effect on the central nervous system are likely to increase the sedative properties of clozapine.
General note
A number of drugs increase the risk of adverse effects on the blood.
Do not take other medication without checking with your doctor or pharmacist.
QUICK REFERENCE
Drug group Antipsychotic
Overdose danger rating Medium
Dependence rating Low
Prescription needed Yes
Available as generic No
SPECIAL PRECAUTIONS
Be sure to tell your doctor if:
You have long-term liver or kidney problems.
You have a history of blood disorders.
You have had epileptic fits.
You are taking other medications.
Pregnancy
Not usually prescribed. Safety not established. Discuss with your doctor.
Breast-feeding
The drug passes into the breast milk and may affect the baby adversely. Discuss with your doctor.
Infants and children
Not prescribed.
Over 60
Adverse effects are more likely. Initial dose is low and is slowly increased.
Driving and hazardous work
Avoid such activities until you have learned how clozapine affects you because the drug can cause drowsiness, dizziness, and blurred vision.
Alcohol
Avoid. Alcohol may increase the sedative effects of this drug.
PROLONGED USE
Agranulocytosis may occur, and occasionally liver function may be upset.
Monitoring
Blood tests are carried out weekly for the first 18 weeks, and fortnightly thereafter. Liver function tests may also be performed.
