Generic Name: Clozapine

  • What is this medication and its most common uses?

    Clozapine is a medicine used to treat severely ill people with schizophrenia who do not respond to standard treatment. Clozapine is also used to reduce the risk of repeated suicidal behavior in people with schizophrenia or schizoaffective disorder who are at risk for experiencing suicidal behavior again.

  • What should I know when beginning and continuing on this medication?

    Clozapine may only be available under a special restricted distribution program. Only doctors and pharmacies registered with the program are able to prescribe and distribute clozapine. In addition, you can only take clozapine if you are enrolled in and meet all conditions of the program. Your healthcare provider will explain the program to you.

    How does this medication work?

    The symptoms of schizophrenia are thought to be caused by chemical imbalances in the brain. Although it is unclear exactly how clozapine works, it seems to help balance the chemicals in the brain, thereby helping to improve your symptoms.

    What are the beneficial effects of this medication and when should I begin to have results?


    Schizophrenia: Clozapine has been shown to relieve symptoms of schizophrenia as measured by appropriate symptom rating scales that are commonly used by healthcare providers to evaluate the effectiveness of the medicine in people with this condition.

    Reduced Risk of Suicidal Behavior: Clozapine has been shown to reduce the chance of experiencing a major suicide attempt and hospitalization due to suicide risk.

    When: Everyone responds differently to treatment, so try to be patient and follow your healthcare provider's directions. It is important that you take clozapine exactly as your healthcare provider has prescribed.

    How do I know it is working?

    Your healthcare provider may ask you questions from time to time to assess how well your symptoms are controlled.

  • What are the possible side effects of this medication?

    The following is not a full list of side effects. Side effects cannot be anticipated. If any develop or change in intensity, tell your healthcare provider as soon as possible. Only your healthcare provider can determine if it is safe for you to continue taking this medication.

    Clozapine can cause agranulocytosis (a blood disorder in which white blood cells are not made in adequate numbers or not made at all) with symptoms of an infection (such as a fever, weakness, lack of energy, or sore throat). Your healthcare provider will monitor your blood cell counts as appropriate.

    Clozapine can cause a sudden fall in blood pressure with symptoms such as dizziness, lightheadedness, or fainting when rising too quickly from a sitting or lying position.

    Clozapine can cause seizures. Tell your healthcare provider if you have a history of seizures.

    Clozapine can cause certain heart problems, with symptoms such as chest pain; fast, fluttery, or throbbing heartbeat; shortness of breath; fever; flu-like symptoms; or low blood pressure.

    Clozapine is not approved to treat mental problems caused by dementia (an illness involving loss of memory and judgment, and confusion) in the elderly. It can be life-threatening when used in elderly people with mental problems caused by dementia.

    More common side effects may include: drowsiness, dizziness, headache, shaking, fast heartbeat, low blood pressure, fainting, increased saliva production, sweating, dry mouth, changes in vision, constipation, nausea, fever.

    Less common side effects may include:

    High blood sugar with symptoms such as excessive thirst, an increase in urination, increased appetite, weakness, confusion, fruity smelling breath, or feeling sick to your stomach.

    Increased cholesterol (fats in your blood) and triglycerides (a type of blood fat), and weight gain.

    Neuroleptic malignant syndrome (NMS) (a life-threatening brain disorder) with symptoms such as high fever, excessive sweating, muscle rigidity, confusion, changes in your breathing, fast or irregular heartbeat, or changes in your blood pressure.

    Tardive dyskinesia, defined as abnormal muscle movements, including tremor, shuffling, and uncontrolled, involuntary movements.

  • Who should not take this medication?

    Do not take clozapine if you are allergic to it or to any of its ingredients.

    Do not take clozapine if you have a disorder involving the abnormal production of blood cells, seizures that are not controlled with medicine, paralytic ileus (impairment of the small intestine), or a history of low white blood cell counts due to clozapine use.

    Do not take clozapine if you are severely sedated.

  • What should I tell my healthcare provider before I take the first dose of this medication?

    Tell your healthcare provider about all prescription, over-the-counter, and herbal medications you are taking before beginning treatment with clozapine. Also, talk to your healthcare provider about your complete medical history, especially if you have diabetes; high cholesterol levels; high or low blood pressure; low white blood cell counts; seizures; glaucoma (high pressure in the eye); an enlarged prostate; heart, liver, or kidney problems; or if you are pregnant, plan to become pregnant, or are breastfeeding.

  • What is the usual dosage?

    The information below is based on the dosage guidelines your healthcare provider uses. Depending on your condition and medical history, your healthcare provider may prescribe a different regimen. Do not change the dosage or stop taking your medication without your healthcare provider's approval.

    Adults: The recommended starting dose is 12.5 milligrams (mg) (half of a 25-mg tablet) once or twice a day. Your healthcare provider may increase your dose as needed, until the desired effect is achieved.

  • How should I take this medication?

    Take clozapine exactly as prescribed by your healthcare provider. Do not change your dose or stop taking clozapine without first talking to your healthcare provider.

    Take clozapine with or without food.

  • What should I avoid while taking this medication?

    Do not drink alcohol while you are taking clozapine without first talking to your healthcare provider.

    Do not drive, operate machinery, or engage in other dangerous activities until you know how clozapine affects you.

  • What are the possible food and drug interactions associated with this medication?

    If clozapine is taken with certain other drugs, the effects of either could be increased, decreased, or altered. Clozapine may interact with numerous medications. Therefore, it is very important that you tell your healthcare provider about any other medications you are taking.

  • May I receive this medication if I am pregnant or breastfeeding?

    The effects of clozapine during pregnancy are unknown. Clozapine can be found in your breast milk if you take it while breastfeeding. Do not breastfeed while you are taking clozapine. Tell your healthcare provider immediately if you are pregnant, plan to become pregnant, or are breastfeeding.

  • What should I do if I miss a dose of this medication?

    If you miss a dose of clozapine, take it as soon as you remember. However, if it is almost time for your next dose, skip the one you missed and return to your regular dosing schedule. Do not take two doses at once.

    If you miss taking clozapine for more than 2 days, contact your healthcare provider for instructions.

  • How should I store this medication?

    Store at room temperature.