Clozapine is a prescription medicine for the treatment of severely ill patients
with schizophrenia, a serious mental illness, who are not helped by other medicines
for schizophrenia (treatment-resistant schizophrenia). It should be used only after
other standard drugs for schizophrenia have either failed or caused serious side
effects. Clozapine is also used for reducing the risk of suicide in patients with
schizophrenia or schizoaffective disorder who have attempted suicide in the past
and may be at risk of suicidal behavior again.
Agranulocytosis. Clozapine therapy
can cause a severe decrease in white blood cells, called agranulocytosis which could
lead to a serious infection and death. You should report any signs or symptoms to
your doctor that may be associated with agranulocytosis or infection such as fever;
mouth sores; skin, throat, vaginal, kidney, bladder or lung infection.
Because of the risk of agranulocytosis, Clozapine is available only through a restricted
program called the Clozapine Patient Registry. Prescribers, patients, and pharmacies
must enroll in the program. Your doctor will schedule frequent blood tests while
taking Clozapine so that he/she can monitor and make sure you are not developing
agranulocytosis. You must have your blood tested before beginning treatment with
Clozapine. If your results are acceptable after weekly blood tests for the first
6 months of treatment, you may be able to have your blood tested every other week
for the next 6 months. After that, testing once each month might be possible. Your
doctor will determine how often you will need testing. When stopping treatment with
Clozapine for any reason, blood tests will continue on a weekly basis for 4 weeks.
Orthostatic Hypotension, Bradycardia, and Syncope: Clozapine can
cause your blood pressure to drop suddenly, called orthostatic hypotension, which
can make you feel dizzy or lightheaded and can lead to fainting (syncope) when you
change position, such as standing or sitting up after lying down. This can also
cause you to stop breathing or your heart to stop beating. Tell your doctor if you
have heart disease or any other cardiovascular or cerebrovascular problems or are
taking medicine for hypertension, or high blood pressure or have experienced dehydration.
Follow your doctor’s instructions for dosage and administration. Contact your doctor
immediately if you feel faint, lose consciousness, or have any signs or symptoms
suggestive of low heart rate or abnormal heart beat.
Seizures. There is a high risk of having seizures during Clozapine
treatment. Tell your doctor if you have a history of seizures or are at risk for
seizures. Alcohol abuse while taking Clozapine may increase the risk of seizures.
You should avoid driving or doing any other dangerous activity while taking Clozapine.
Myocarditis and Cardiomyopathy. Clozapine can cause an inflammation
of the heart muscle, known as cardiomyopathy and myocarditis, which can be life-threatening.
Tell your doctor if you experience any chest pain, difficulty breathing, an increase
in heart rate, palpitations, fever, flu-like symptoms, or low blood pressure. Patients
with Clozapine-related myocarditis or cardiomyopathy should not take Clozapine again.
Elderly patients with a mental illness called dementia-related psychosis and
who are taking antipsychotic drugs, such as Clozapine, are at a higher risk of death.
Clozapine is not approved for use in these patients.
- You should not take Clozapine if you:
- Have had blood problems called agranulocytosis or severe granulocytopenia after
- Are allergic or had an allergic reaction (photosensitivity, vasculitis, erythema
multiforme, or Stevens-Johnson syndrome) to Clozapine or any of the ingredients
Eosiniphilia. Clozapine treatment can cause eosinophilia, or an
increase in the number of white blood cells. This usually occurs during the first
month of treatment and has been associated with inflammation of the heart, pancreas,
liver, colon and kidneys. If it is suspected, Clozapine should be discontinued immediately.
QT Prolongation. Clozapine treatment is associated with abnormal
heartbeat that can become life-threatening. Tell your doctor if you, or anyone in
your family, have had any heart problems. You should not use Clozapine with other
medicines that are known to cause any heart problems. Notify your doctor if you
feel faint, lose consciousness or have abnormal heartbeat.
Neuroleptic Malignant Syndrome (NMS). Clozapine can cause NMS,
a condition that can be life-threatening. Tell your doctor right away if you have
high fever, stiff muscles, confusion, sweating, or changes in your heart rate or
Pulmonary Embolism. Pulmonary embolism (blood clot in the lungs)
and deep vein thrombosis have occurred in patients treated with Clozapine. Patients
should report pain in their legs (deep vein thrombosis), shortness of breath, chest
pain or other respiratory signs and symptoms to their doctor.
Anticholinergic Toxicity. Clozapine should be used with caution
in patients who have narrow-angle glaucoma, are taking other anticholinergic medications,
or have enlarged prostates. Clozapine can result in gastrointestinal adverse reactions,
which may be fatal, including constipation, fecal impaction, or paralytic ileus.
Tell your doctor if you have ever had any eye, prostate or colon problems and about
all of the medications you are taking.
Tardive Dyskinesia (TD). Clozapine can cause TD, a serious, sometimes
permanent, condition in which you have uncontrolled movements of the face or other
parts of the body. The risk for developing TD can increase over time with more medicine,
but can also develop within a short time and at low doses. There is no known treatment
for TD, but it may go away partially or completely if the medicine is stopped.
Metabolic Changes (hyperglycemia and diabetes mellitus, dyslipidemia, weight
gain). Clozapine is associated with metabolic changes that require
specific monitoring. The risks include hyperglycemia and diabetes mellitus, dyslipidemia,
weight gain, and cardiovascular reactions. Clozapine can cause an increase in the
amount of glucose, or sugar, in your blood, called hyperglycemia. Your doctor may
check your blood sugar level before you start taking Clozapine and periodically
during treatment. Tell your Doctor right away if you have any of the following symptoms
while taking Clozapine: you are very thirsty, urinate very often, are very hungry,
have blurry vision, or feel weak. Tell your doctor if you have diabetes or if you
are at risk for diabetes (because of obesity or because someone in your family has
diabetes).Abnormal lipids or cholesterol levels have occurred in patients treated
with Clozapine. Weight gain has also occurred with the use of Clozapine. Monitoring
of weight and cholesterol levels at baseline and during Clozapine therapy is recommended.
Effect on Behavior and or Physical Abilities. Clozapine can affect how you think or behave and/or your physical abilities, and may make you feel sleepy and less alert, especially during the first few days of treatment. Do not drive or operate heavy machinery until you know how Clozapine affects you. Ask your doctor when it would be okay to do these activities.
Missed Doses and Re-initiating Treatment. Tell your doctor if you miss a dose of Clozapine for more than two days. You should not restart your medication, and contact your doctor for dosing instructions.
Pregnancy and Nursing. Clozapine should be used in pregnancy only if the potential benefit is greater than the potential risk to the fetus. Tell your doctor if you are pregnant or plan to become pregnant. You should not breastfeed while taking Clozapine.
Use with Other Medications. Tell your doctor about all of the medicines you are taking, including over-the-counter medicines. There is a potential that the drugs could interact with each other.
Clozapine, USP Orally Disintegrating Tablets contain phenylalanine (a component of aspartame).
Common Side Effects. The most common side effects of Clozapine are feeling drowsy or sleepy, feeling dizzy or lightheaded, headache, trembling, fast heart rate, low blood pressure, fainting, excess salivation, sweating, dry mouth, vision changes, constipation, nausea, and fever.
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch, or call 800.FDA.1088.