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What is the most important information I should know about clozapine?

Clozapine is not for use in psychotic conditions related to dementia. Clozapine may cause heart failure, sudden death, or pneumonia in older adults with dementia-related conditions.

You should not take clozapine if you have uncontrolled epilepsy, paralytic ileus or intestinal blockage, an infection caused by clozapine, or if you are also using drugs that weaken your immune system (such as cancer medicine or steroids).

While you are taking clozapine, your blood may need to be tested every week for the first 6 months of treatment. Do not miss any scheduled blood tests.

Do not stop taking clozapine or change your dose without first talking to your doctor.

Call your doctor if you have shortness of breath, swelling in your hands or feet, fever, sore throat, sudden numbness or weakness, sudden vision or speech problems, chest pain, cough, wheezing, pain or swelling in one or both legs, seizure, or jaundice (yellowing of your skin or eyes).

There are many other medicines that can interact with clozapine. Tell your doctor about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor. Keep a list with you of all the medicines you use and show this list to any doctor or other healthcare provider who treats you.

Warning

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

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What is clozapine?

Clozapine is an antipsychotic medication. It works by changing the actions of chemicals in the brain.

Clozapine is used to treat severe schizophrenia symptoms in people who have not responded to other medications. Clozapine is also used to help reduce the risk of suicidal behavior in people with schizophrenia or similar disorders.

Clozapine may also be used for other purposes not listed in this medication guide.

Precautions

Clozapine is not for use in psychotic conditions related to dementia. Clozapine may cause heart failure, sudden death, or pneumonia in older adults with dementia-related conditions.

You should not take this medication if you are allergic to clozapine, or if you have:

  • untreated or uncontrolled epilepsy;
  • paralytic ileus or intestinal blockage;
  • a history of infection while taking clozapine; or
  • if you are also using drugs that weaken your immune system (such as cancer medicine or steroids).

If you have certain conditions, you may need a dose adjustment or special tests to safely use this medication. Before taking clozapine, tell your doctor if you have:

  • heart disease, heart rhythm disorder, high blood pressure, or a history of heart attack;
  • liver or kidney disease;
  • lung disease;
  • diabetes;
  • a history of bone marrow or blood cell disorders;
  • glaucoma; or
  • an enlarged prostate or urination problems.

Clozapine may raise your blood sugar, causing symptoms such as increased thirst, loss of appetite, increased urination, drowsiness, nausea, or fruity breath odor. Call your doctor right away if you have any of these symptoms.

FDA pregnancy category B: This medication is not expected to be harmful to an unborn baby. Do not use clozapine without telling your doctor if you are pregnant or plan to become pregnant during treatment.

Clozapine can pass into breast milk and may harm a nursing baby. You should not use this medication if you are breast-feeding a baby.

Clozapine orally-disintegrating tablets contain phenylalanine. Talk to your doctor before using this form of clozapine if you have phenylketonuria (PKU).

Clozapine may cause seizures, dizziness, or fainting. Be careful if you drive or do anything that requires you to be awake and alert.

Avoid drinking alcohol. It can increase some of the side effects of clozapine.

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Instructions

Seek emergency medical attention if you think you have used too much of this medicine.

Overdose symptoms may include confusion, fast heart rate, drowsiness, drooling, weak or shallow breathing, feeling like you might pass out, and seizure (convulsions).

Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and take the medicine at the next regularly scheduled time. Do not take extra medicine to make up the missed dose.

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Side Effects

Stop using clozapine and get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have any of these serious side effects:

  • feeling short of breath, even at night or with mild exertion;
  • swelling in your hands or feet;
  • fever, weakness, sore throat, stiff muscles, confusion, sweating, fast or uneven heartbeats;
  • sudden numbness or weakness, especially on one side of the body;
  • sudden headache, confusion, problems with vision, speech, or balance;
  • chest pain, sudden cough, wheezing, rapid breathing, fast heart rate, pain or swelling in one or both legs;
  • white patches or sores inside your mouth or on your lips;
  • nausea, vomiting, loss of appetite, and jaundice (yellowing of your skin or eyes); or
  • seizure (black-out or convulsions).

Less serious side effects may include:

  • constipation;
  • drooling, especially at night;
  • increased sweating;
  • drowsiness, dizziness, spinning sensation;
  • sleep problems or nightmares; or
  • weight gain.

This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effect. You may report side effects to FDA at 1-800-FDA-1088.

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Interactions

Before taking clozapine, tell your doctor if you are using any of the following drugs:

  • cimetidine (Tagamet);
  • citalopram (Celexa);
  • lithium (Eskalith, Lithobid);
  • rifampin (Rifadin, Rimactane);
  • blood pressure medications;
  • heart rhythm medications such as propafenone (Rythmol) or flecaininde (Tambocor);
  • seizure medicine such as phenytoin (Dilantin) or carbamazepine (Carbatrol, Tegretol);
  • antibiotics such as ciprofloxacin (Cipro) or erythromycin (E-Mycin, E.E.S, Ery-Tab);
  • atropine (Donnatal, and others), belladonna, clidinium (Quarzan), dicyclomine (Bentyl), scopolamine (Transderm-Scop); or
  • diazepam (Valium) or similar medicines such as alprazolam (Xanax), clonazepam (Klonopin), lorazepam (Ativan), midazolam (Versed), temazepam (Restoril), and others.

This list is not complete and there may be other drugs that can interact with clozapine. Tell your doctor about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor.

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Disclaimer

Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

Copyright 1996-2004 Cerner Multum, Inc. Version 2.05. Revision date 8/23/04