Clozapine Full Prescribing Information
Brand Name: Clozaril
Generic Name: Clozapine
Clozaril (Clozapine) is an antipsychotic used to treat schizophrenia in treatment-resistant schizophrenic patients. Usage, dosage, side effects of Clozaril.
Outside U.S., Brand Names also known as: Leponex
Clozaril patient information (in plain English)
Clozapine (Clozaril) is an antipsychotic used to treat schizophrenia in patients who have not been helped by or are unable to take other medicines.
Clozapine is only available from pharmacies that agree to participate with your doctor in a plan to monitor your blood tests. You will need to have blood tests done every week, and you will receive a 7-day supply of clozapine only if the results of your blood tests show that it is safe for you to take this medicine.
Clozaril (Clozapine) is a dibenzodiazepine derivative which exerts potent anticholinergic, adrenolytic, antihistaminic and antiserotonergic activity.
On rare occasions, patients may report an intensification of dream activity during clozapine therapy.
Depending on the individual, peak plasma concentrations occur approximately 2.5 hours after dosing (range: 1 to 6 hours) .
Indications and Usage
Clozaril (Clozapine) should be limited to treatment-resistant schizophrenic patients who are non-responsive to, or intolerant of, conventional antipsychotic drugs.
With this medication comes the significant risk of agranulocytosis and seizure.
Patients with a history of drug-induced agranulocytosis or severe granulocytopenia or myeloproliferative disorders. Clozapine should not be used simultaneously with other medications known to suppress bone marrow function.
Other contraindications include severe CNS depression or comatose states, severe hepatic, renal or cardiac disease, and uncontrolled epilepsy.
Make sure you tell your doctor if you have any other medical problems, especially blood diseases, enlarged prostate or difficult urination, or epilepsy or other seizure disorder.
DO NOT STOP TAKING THIS MEDICINE without first checking with your doctor. Your doctor may want you to reduce gradually the amount you are taking before stopping completely.
It is important that you have your blood tests done weekly and that your doctor check your progress at regular visits. This will allow your doctor to make sure the medicine is working properly and to change the dosage if needed.
Agranulocytosis: Because of the significant risk of agranulocytosis, a potentially life-threatening adverse event, clozapine should be reserved for use in the treatment of schizophrenic patients who fail to show an acceptable response to adequate courses of conventional antipsychotic drug treatment, either because of insufficient effectiveness or the inability to achieve an effective dose due to intolerable adverse effects.
Clozapine will add to the effects of other medicines and alcohol.
Do not become overheated in hot weather, during exercise or other activities since heat stroke may occur while you are taking this medicine.
Avoid large amounts of caffeine-containing foods and beverages, such as coffee, tea, cocoa, cola drinks, and chocolate.
Seizures: Caution should be used in administering clozapine to patients having a history of seizures or other predisposing factors.
Cardiovascular: Clozapine should be used with caution in patients with underlying cardiovascular disease or arrhythmias.
Neuroleptic Malignant Syndrome: A potentially fatal symptom complex sometimes referred to as neuroleptic malignant syndrome (NMS) has been reported in association with antipsychotic drugs. There have been several reported cases of NMS in patients treated with clozapine, most of which have included the concomitant use of lithium or other CNS-active agents.
NMS Symptoms are: hyperpyrexia, muscle rigidity, altered mental status (including catatonic signs) and evidence of irregular pulse or blood pressure, tachycardia, diaphoresis and cardiac dysrhythmias.
Interference with Cognitive or Motor Performance: Clozapine drowsiness or dizziness. If dizziness occurs, sit up or stand up slowly. Do not drive, operate machinery, or do anything else that could be dangerous until you know how you react to this medicine.
Pregnancy and Withdrawl: The safety of the use of clozapine in pregnancy has not been established. Therefore, clozapine is not recommended for use during pregnancy and should only be used if the benefits clearly outweigh the risks. Women receiving clozapine should not breast-feed.
This medicine may cause weight gain. If you notice weight gain and are concerned, discuss it with your doctor.
Before taking this medicine, inform your doctor or pharmacist of all prescription and over-the-counter medicine that you are taking. This includes ritonavir, carbamazepine, fluoxetine, fluvoxamine, paroxetine, risperidone, sertraline, tramadol, benzodiazepines, and ACE inhibitors. Inform your doctor of any other medical conditions, allergies, pregnancy, or breast-feeding.
The most serious adverse reactions experienced with clozapine are agranulocytosis, seizure, cardiovascular effects and fever.
CHECK WITH YOUR DOCTOR AS SOON AS POSSIBLE if you experience sweating, stiff muscles, fast pulse, irregular heartbeat; seizures; weakness; sore throat or fever.
The most common side effects are drowsiness, dizziness, hypersalivation, dry mouth, tachycardia and sedation. Other side effects are constipation, headache, nausea, and changes in eyesight.
Signs and Symptoms
Dizziness or fainting; drowsiness (severe); fast, slow, or irregular heartbeat; hallucinations (seeing, hearing, or feeling things that are not there); increased watering of mouth (severe); slow, irregular, or troubled breathing; unusual excitement, nervousness, or restlessness.
Fatal overdoses have been reported with clozapine, generally at doses above 2500 mg.
If you or someone you know may have used more than the recommended dose of this medicine, contact your local poison control center or emergency room immediately.
There are no specific antidotes for clozapine.
Establish and maintain an airway; ensure adequate oxygenation and ventilation. Activated charcoal, which may be used with sorbitol, may be as or more effective than emesis or lavage, and should be considered in treating overdosage. Cardiac and vital signs monitoring is recommended along with general symptomatic and supportive measures. Surveillance should be continued for several days because of the risk of delayed effects. Avoid epinephrine and derivatives when treating hypotension, and quinidine and procainamide when treating cardiac arrhythmia.
DO NOT STOP TAKING THIS MEDICINE without first checking with your doctor.
- Follow the directions for using this medicine provided by your doctor.
- Store this medicine at room temperature, away from heat and light.
- If you miss a dose of this medicine, take it as soon as possible. If it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not take 2 doses at once.
Additional Information: Do not share this medicine with others for whom it was not prescribed. Do not use this medicine for other health conditions. Keep this medicine out of the reach of children.
The dose of clozapine will be different for different patients. For schizophrenia: Adults- At first, 25 milligrams (mg) once or twice a day. Your doctor may increase your dose as needed. However, the dose is usually not more than 900 mg a day.
Children up to 16 years of age: Use and dose must be determined by your doctor.
IF USING THIS MEDICINE FOR AN EXTENDED PERIOD OF TIME, obtain refills before your supply runs out.
25 mg and 100 mg tablets.
Last updated: March, 2003
Clozaril patient information (in plain English)
The information in this monograph is not intended to cover all possible uses, directions, precautions, drug interactions or adverse effects. This information is generalized and is not intended as specific medical advice. If you have questions about the medicines you are taking or would like more information, check with your doctor, pharmacist, or nurse. Last updated 3/03.
Last Updated: 28 March 2017
Reviewed by Harry Croft, MD