"May 2, 2012 -- More than 50 years of data show that people with schizophrenia who take antipsychotic drugs lower their risk of relapse, a new study suggests.
Relapse rates were 64% in people not taking medications for schizophrenia, w"...
Fazaclo Side Effects Center
Medical Editor: John P. Cunha, DO, FACOEP
FazaClo (clozapine) is used to treat severe schizophrenia symptoms in people who have not responded to other medications. It is also used to help reduce the risk of suicidal behavior in people with schizophrenia or similar disorders. It is an antipsychotic medication. Common side effects include drooling, drowsiness, dizziness, headache, shaking (tremor), vision problems (e.g., blurred vision) and constipation. Many of these effects (especially drowsiness) lessen as the body gets used to the medication.
It is recommended that treatment with FazaClo begin with a 12.5 mg dose once or twice daily. The dosing should be continued with daily dosage increments of 25-50 mg/day, if well-tolerated, to achieve a target dose of 300-450 mg/day by the end of 2 weeks. FazaClo may interact with cimetidine, citalopram, lithium, rifampin, blood pressure medications, heart rhythm medications, seizure medicines, antibiotics, atropine, belladonna, clidinium, dicyclomine, scopolamine, or diazepam or similar medicines. Tell your doctor all medications and supplements you use. During pregnancy, FazaClo should be used only when prescribed. Do not stop taking this medication unless directed by your doctor. Babies born to mothers who have used this drug during the last 3 months of pregnancy may infrequently develop symptoms including muscle stiffness or shakiness, drowsiness, feeding/breathing difficulties, or constant crying. If you notice symptoms in your newborn during their first month, tell the doctor. This medication may pass into breast milk and have undesirable effects on a nursing infant. Breastfeeding is not recommended while taking this drug.
Our FazaClo (clozapine) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
What is Patient Information in Detail?
Easy-to-read and understand detailed drug information and pill images for the patient or caregiver from Cerner Multum.
Fazaclo in Detail - Patient Information: Side Effects
Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Serious and sometimes fatal infections may occur during treatment with clozapine. Call your doctor right away if you have signs of infection such as:
- fever, chills, body aches, flu symptoms;
- mouth and throat ulcers;
- cough, sore throat;
- rapid heart rate; or
- rapid and shallow breathing.
Stop using clozapine and call your doctor at once if you have any of these serious side effects:
- seizure (black-out or convulsions);
- skin rash, bruising, severe tingling, numbness, pain, muscle weakness;
- fast or pounding heartbeats, chest pain, unusual tiredness, trouble breathing;
- feeling short of breath (even at night or with mild exertion), swelling in your hands or feet;
- feeling like you might pass out;
- slow heart rate, weak pulse, fainting, slow breathing (breathing may stop);
- high blood sugar (increased thirst, extreme hunger, fruity breath odor, increased urination, drowsiness);
- very stiff (rigid) muscles, high fever, sweating, confusion, fast or uneven heartbeats, tremors;
- twitching or uncontrollable movements of your eyes, lips, tongue, face, arms, or legs; or
- nausea, vomiting, loss of appetite, and jaundice (yellowing of your skin or eyes).
Less serious side effects may include:
- dry mouth, blurred vision;
- drooling, especially at night;
- increased sweating;
- drowsiness, dizziness, spinning sensation; or
- sleep problems.
Read the entire detailed patient monograph for Fazaclo (Clozapine) »
What is Prescribing information?
The FDA package insert formatted in easy-to-find categories for health professionals and clinicians.
Fazaclo FDA Prescribing Information: Side Effects
The following adverse reactions are discussed in more detail in other sections of the labeling:
- Agranulocytosis [see WARNINGS AND PRECAUTIONS].
- Orthostatic Hypotension, Bradycardia, and Syncope [see WARNINGS AND PRECAUTIONS].
- Seizures [see WARNINGS AND PRECAUTIONS].
- Myocarditis and Cardiomyopathy [see WARNINGS AND PRECAUTIONS].
- Increased Mortality in Elderly Patients with Dementia-Related Psychosis [see WARNINGS AND PRECAUTIONS].
- Eosinophilia [see WARNINGS AND PRECAUTIONS].
- QT Interval Prolongation [see WARNINGS AND PRECAUTIONS].
- Metabolic Changes (Hyperglycemia and Diabetes Mellitus, Dyslipidemia, and Weight Gain) [see WARNINGS AND PRECAUTIONS].
- Neuroleptic Malignant Syndrome [see WARNINGS AND PRECAUTIONS].
- Fever [see WARNINGS AND PRECAUTIONS].
- Pulmonary Embolism [see WARNINGS AND PRECAUTIONS].
- Anticholinergic Toxicity [see WARNINGS AND PRECAUTIONS].
- Interference with Cognitive and Motor Performance [see WARNINGS AND PRECAUTIONS].
- Tardive Dyskinesia [see WARNINGS AND PRECAUTIONS].
- Patients with Phenylketonuria [see WARNINGS AND PRECAUTIONS].
- Cerebrovascular Adverse Reactions [see WARNINGS AND PRECAUTIONS].
- Recurrence of Psychosis and Cholinergic Rebound after Abrupt Discontinuation [see WARNINGS AND PRECAUTIONS].
Clinical Trials Experience
Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice.
The most commonly reported adverse reactions ( ≥ 5%) across clozapine clinical trials were: CNS reactions, including sedation, dizziness/vertigo, headache, and tremor; cardiovascular reactions, including tachycardia, hypotension, and syncope; autonomic nervous system reactions, including hypersalivation, sweating, dry mouth, and visual disturbances; gastrointestinal reactions, including constipation and nausea; and fever. Table 8 summarizes the most commonly reported adverse reactions ( ≥ 5%) in clozapine-treated patients (compared to chlorpromazinetreated patients) in the pivotal, 6-week, controlled trial in treatment-resistant schizophrenia.
Table 8: Common Adverse Reactions ( ≥ 5%) in the
6-Week, Randomized, Chlorpromazinecontrolled Trial in Treatment-Resistant
(N = 126)
(N = 142)
Table 9 summarizes the adverse reactions reported in clozapine-treated patients at a frequency of 2% or greater across all clozapine studies (excluding the 2-year InterSePT™ Study). These rates are not adjusted for duration of exposure.
Table 9: Adverse Reactions
( ≥ 2%) Reported in Clozapine-treated Patients (N=842) across all
Clozapine Studies (excluding the 2-year InterSePT™ Study)
|Body System Adverse Reaction||Clozapine
N = 842
Percentage of Patients
|Central Nervous System|
|Autonomic Nervous System|
|† Rate based on population of approximately 1700 exposed during premarket clinical evaluation of clozapine.|
Table 10 summarizes the most commonly reported adverse reactions ( ≥ 10% of the clozapine or olanzapine group) in the InterSePT™ Study. This was an adequate and well-controlled, two-year study evaluating the efficacy of clozapine relative to olanzapine in reducing the risk of suicidal behavior in patients with schizophrenia or schizoaffective disorder. The rates are not adjusted for duration of exposure.
Table 10: Incidence of Adverse Reactions in Patients
Treated with Clozapine or Olanzapine in the InterSePT™ Study ( ≥ 10% in
the clozapine or olanzapine group)
N = 479
N = 477
|Dizziness (excluding vertigo)||27%||12%|
Class effect: Symptoms of dystonia, prolonged abnormal contractions of muscle groups, may occur in susceptible individuals during the first few days of treatment. Dystonic symptoms include: spasm of the neck muscles, sometimes progressing to tightness of the throat, swallowing difficulty, difficulty breathing, and/or protrusion of the tongue. While these symptoms can occur at low doses, they occur more frequently and with greater severity with high potency and at higher doses of first generation antipsychotic drugs. An elevated risk of acute dystonia is observed in males and younger age groups.
The following adverse reactions have been identified during post-approval use of clozapine. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.
Central Nervous System
Myasthenic syndrome and rhabdomyolysis.
Hemic and Lymphatic System
Read the entire FDA prescribing information for Fazaclo (Clozapine) »
Additional Fazaclo Information
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
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