clozaril
Clozaril (Clozapine) is an atypical antipsychotic used to treat Bipolar Disorder, Psychotic Disorders, Schizophrenia.
Clozapine · by Heritage Life
Available as a generic: Clozapine
Key facts
- Active ingredient
- Clozapine
- Drug class
- Atypical Antipsychotic
- Form
- Tablet
- Strength
- Clozapine 100MG · Clozapine 200MG **Federal Register Determination That Product was not Discontinued or Withdrawn for Safety or Effectiveness reasons** · Clozapine 25MG · Clozapine 50MG **Federal Register Determination That Product was not Discontinued or Withdrawn for Safety or Effectiveness reasons**
- Type
- Prescription (Rx)
- Brand or generic
- Brand-name
- May treat
- bipolar disorder, psychotic disorders, schizophrenia
- Manufacturer
- Heritage Life
- Half-life
- about 12 hours at steady state (the label gives a mean elimination half-life of 12 hours, range 4 to 66 hours, after 100 mg twice daily); after a single 75 mg dose the mean is 8 hours (range 4 to 12 hours) (how long it stays in your system)
- What the pharmacy pays
- ~$30.62 for 30 — not your price
- FDA application
- NDA019758
- FDA boxed warning
- Yes — see the boxed warning
What is Clozaril?
From the FDA label:CLOZARIL ® (clozapine), an atypical antipsychotic drug, is a tricyclic dibenzodiazepine derivative, 8-chloro-11-(4-methyl-1-piperazinyl)-5 H -dibenzo [ b,e ] [1,4] diazepine. The structural formula is: CLOZARIL is available in pale yellow tablets of 25 mg and 100 mg for oral administration. Active Ingredient: clozapine Inactive Ingredients are colloidal silicon dioxide, lactose, magnesium stearate, povidone, starch (corn), and talc. structural formula
How to use
Recommended starting oral dosage is 12.5 mg once daily or twice daily. ( 2.2 ) • If well-tolerated, increase the total daily dosage in increments of 25 mg to 50 mg per day to achieve a target dosage of 150 mg to 225 mg twice per day by the end of two weeks. ( 2.2 ) • Subsequently may increase the dosage in increments up to 100 mg once or twice weekly ( 2.2 ) • Maximum daily dosage is 450 mg twice daily. ( 2.2 ) • Administer with or without food. ( 2.2 ) • See the dosage modifications based on ANC results and recommended frequency of ANC testing in the full prescribing information. ( 2.3 , 2.4 ) • See recommendations for discontinuing CLOZARIL treatment ( 2.5 ), restarting CLOZARIL after interrupting dosing ( 2.6 ), dosage modifications for drug interactions( 2.7 ), dosage recommendations in patients with renal or hepatic impairment and CYP2D6 poor metabolizers ( 2.8 ) in the full prescribing information. 2.1 Absolute Neutrophil Count Testing Prior to CLOZARIL Initiation Prior to initiating CLOZARIL treatment, obtain a baseline absolute neutrophil count (ANC). CLOZARIL initiation is not recommended in patients with an ANC less than 1500/μL [see Warnings and Precautions ( 5.1 )] . For patients with documented Benign Ethnic Neutropenia (BEN) (also known as Duffy-null associated neutrophil count), obtain at least two baseline ANC levels. CLOZARIL initiation is not recommended in…
Side effects
The following adverse reactions are discussed in more detail in other sections of the labeling: • Severe Neutropenia [see Warnings and Precautions ( 5.1 )] • Orthostatic Hypotension, Bradycardia, and Syncope [see Warnings and Precautions ( 5.2 )] • Falls [see Warnings and Precautions ( 5.3 )] • Seizures [see Warnings and Precautions ( 5.4 )] • Myocarditis, Pericarditis, Cardiomyopathy, and Mitral Valve Incompetence [see Warnings and Precautions ( 5.5 )] • Increased Mortality in Elderly Patients with Dementia-Related Psychosis [see Warnings and Precautions ( 5.6 )] • Gastrointestinal Hypomotility with Severe Complications [See Warnings and Precautions ( 5.7) ] • Eosinophilia [see Warnings and Precautions ( 5.8 )] • QT Interval Prolongation [see Warnings and Precautions ( 5.9 )] • Metabolic Changes (Hyperglycemia and Diabetes Mellitus, Dyslipidemia, and Weight Gain) [see Warnings and Precautions ( 5.10 )] • Neuroleptic Malignant Syndrome [see Warnings and Precautions ( 5.11 )] • Hepatotoxicity [see Warnings and Precautions ( 5.12 )] • Fever [see Warnings and Precautions ( 5.13 )] • Pulmonary Embolism [see Warnings and Precautions ( 5.14 )] • Anticholinergic Toxicity [see Warnings and Precautions ( 5.15 )] • Interference with Cognitive and Motor Performance [see Warnings and Precautions ( 5.16 )] • Tardive Dyskinesia [see Warnings and Precautions ( 5.17 )] • Cerebrovascular…
FDA Boxed Warning (the FDA’s most serious warning)
Boxed (black-box) warning — from the FDA label
SEVERE NEUTROPENIA; ORTHOSTATIC HYPOTENSION, BRADYCARDIA, AND SYNCOPE; SEIZURE; MYOCARDITIS, PERICARDITIS AND CARDIOMYOPATHY; INCREASED MORTALITY IN ELDERLY PATIENTS WITH DEMENTIA-RELATED PSYCHOSIS Severe Neutropenia CLOZARIL has caused severe neutropenia which is associated with an increased risk of serious and potentially fatal infections. Prior to initiating CLOZARIL treatment, obtain baseline ANC(s). CLOZARIL initiation is not recommended in patients with a baseline ANC less than 1500/μL (less than 1000/μL for those with Benign Ethnic Neutropenia (also known as Duffy-null associated neutrophil count)). See recommendations for dosage modifications based on ANC levels during CLOZARIL treatment [see Dosage and Administration ( 2.3 , 2.4 )] . Consider a hematology consultation before initiating CLOZARIL or during CLOZARIL treatment [see Warnings and Precautions ( 5.1 )] . Orthostatic Hypotension, Bradycardia, Syncope Orthostatic hypotension, bradycardia, syncope, and cardiac arrest have occurred with CLOZARIL treatment. The risk is highest during the initial titration period, particularly with rapid dose escalation. These reactions can occur with the first dose, with doses as low as 12.5 mg per day, or when restarting patients who have had even a brief interruption in treatment with CLOZARIL. Initiate treatment at 12.5 mg once or twice daily; titrate slowly; and use divided dosages to minimize risk. Use CLOZARIL cautiously in patients with cardiovascular or cerebrovascular disease or conditions predisposing to hypotension (e.g., dehydration, use of antihypertensive medications) [see Dosage and Administration ( 2.2 , 2.6 ), Warnings and Precautions ( 5.2 )]. Seizures Seizures have occurred with CLOZARIL treatment. The risk is dose-related. Initiate treatment at 12.5 mg, titrate gradually, and use divided dosing. Use caution when administering CLOZARIL to patients with a history of seizures or other predisposing risk factors for seizure (CNS pathology, medications that lower the seizure threshold, alcohol abuse). Caution patients about engaging in any activity where sudden loss of consciousness could cause serious risk to themselves or others [see Dosage and Administration ( 2.2 ), Warnings and Precautions ( 5.4 )]. Myocarditis, Pericarditis, Cardiomyopathy and Mitral Valve Incompetence Fatal myocarditis and cardiomyopathy have occurred with CLOZARIL treatment. Discontinue CLOZARIL and obtain a cardiac evaluation upon suspicion of these reactions. Generally, patients with CLOZARIL-related myocarditis or cardiomyopathy should not be rechallenged with CLOZARIL. Consider the possibility of myocarditis, pericarditis, or cardiomyopathy if chest pain, tachycardia, palpitations, dyspnea, fever, flu-like symptoms, hypotension, or ECG changes occur [see Warnings and Precautions( 5.5 )] . Increased Mortality in Elderly Patients with Dementia-Related Psychosis Elderly patients with dementia-related psychosis treated with antipsychotic drugs are at an increased risk of death. CLOZARIL is not approved for use in patients with dementia-related psychosis [see Warnings and Precautions ( 5.6 )]. WARNING: SEVERE NEUTROPENIA; ORTHOSTATIC HYPOTENSION, BRADYCARDIA, AND SYNCOPE; SEIZURE; MYOCARDITIS, PERICARDITIS AND CARDIOMYOPATHY; INCREASED MORTALITY IN ELDERLY PATIENTS WITH DEMENTIA-RELATED PSYCHOSIS See full prescribing information for complete boxed warning. • Severe Neutropenia: CLOZARIL has caused severe neutropenia, which is associated with an increased risk of serious and fatal infections. Prior to initiating CLOZARIL treatment, obtain baseline ANC(s). CLOZARIL initiation is not recommended in patients with a baseline ANC less than 1500/ μ L (less than 1000 μ L for those with Benign Ethnic Neutropenia (also known as Duffy-null associated neutrophil count)). See recommendations for dosage modifications based on ANC levels during CLOZARIL treatment ( 2.3 , 2.4 , 5.1 ) • Orthostatic Hypotension, Bradycardia, and Syncope: Risk is dose-related. Starting dose is 12.5 mg. Titrate gradually and use divided dosages. ( 2.2 , 2.6 , 5.2 ) • Seizure: Risk is dose-related. Titrate gradually and use divided doses. Use with caution in patients with history of seizure or risk factors for seizure. ( 2.2 , 5.4 ) • Myocarditis, Pericarditis, Cardiomyopathy and Mitral Valve Incompetence: Can be fatal. Discontinue and obtain cardiac evaluation if findings suggest these cardiac reactions. ( 5.5 ) • Increased Mortality in Elderly Patients with Dementia-Related Psychosis: CLOZARIL is not approved for this condition. ( 5.6 )
Warnings
Important safety information
Severe neutropenia : See Boxed Warnings ( 5.1 ) • Gastrointestinal Hypomotility with Severe Complications : Severe gastrointestinal adverse reactions have occurred with the use of CLOZARIL. If constipation is identified, close monitoring and prompt treatment is advised. ( 5.7 ) • Eosinophilia : Assess for organ involvement (e.g., myocarditis, pancreatitis, hepatitis, colitis, nephritis). Discontinue if these occur. ( 5.8 ) • QT Interval Prolongation : Can be fatal. Consider additional risk factors for prolonged QT interval (disorders and drugs). ( 5.9 ) • Metabolic Changes : Atypical antipsychotic drugs have been associated with metabolic changes that may increase cardiovascular/cerebrovascular risk. These metabolic changes include: 1. Hyperglycemia and Diabetes Mellitus : Monitor for symptoms of hyperglycemia including polydipsia, polyuria, polyphagia, and weakness. Monitor glucose regularly in patients with diabetes or at risk for diabetes. ( 5.10 ) 2. Dyslipidemia : Undesirable alterations in lipids have occurred in patients treated with atypical antipsychotics. ( 5.10 ) 3. Weight Gain : Significant weight gain has occurred. Monitor weight gain. ( 5.10 ) • Neuroleptic Malignant Syndrome (NMS) : Immediately discontinue and monitor closely. Assess for co-morbid conditions. ( 5.11 ) • Hepatotoxicity : Can be fatal. Monitor for hepatotoxicity. Discontinue treatment if hepatitis or transaminase elevations combined with other symptoms occur ( 5.12 ). • Fever : Evaluate for infection and for neutropenia, NMS. ( 5.13 ) • Pulmonary Embolism (PE) : Consider PE if respiratory distress, chest pain, or deep-vein thrombosis occur. ( 5.14 ) • Anticholinergic Toxicity : When possible, avoid use with other anticholinergic drugs and use with caution in patients with a current diagnosis or prior history of constipation, urinary retention, clinically significant prostatic hypertrophy, or other conditions in which anticholinergic effects can lead to significant adverse reactions. ( 5.15 , 7.1 ) • Interference with Cognitive and Motor Performance : Advise caution when operating machinery, including automobiles. ( 5.16 ) 5.1 Severe Neutropenia CLOZARIL has caused severe neutropenia (absolute neutrophil count (ANC) less than 500/μL) [see Adverse Reactions ( 6.1 , 6.2 )] and is associated with an increased risk of serious and potentially fatal infections. Severe neutropenia occurred in a small percentage of CLOZARIL-treated patients. The risk of severe neutropenia appears greatest during the first 18 weeks of CLOZARIL treatment. The mechanism by which CLOZARIL causes neutropenia is unknown. Neutropenia is not dose dependent. Consider a hematology consultation before initiating CLOZARIL treatment or during treatment. ANC Monitoring and Dosage Modifications Prior to initiating CLOZARIL treatment, obtain a baseline ANC. CLOZARIL initiation is not recommended in patients with a baseline ANC less than 1500/μL. Throughout CLOZARIL treatment, regularly monitor ANC. Table 1 provides recommendations for dosage modifications (dosage interruption and treatment discontinuation), based on ANC levels, during CLOZARIL treatment and frequency of ANC monitoring [see Dosage and Administration ( 2.3 )]. ANC Monitoring and Dosage Modification in Patients with Benign Ethnic Neutropenia Patients with Benign Ethnic Neutropenia (BEN) (also known as Duffy-null associated neutrophil count) generally have lower baseline neutrophil counts but they are not at higher risk for developing infections, and they are not at increased risk for developing CLOZARIL-induced neutropenia. For patients with documented BEN, obtain at least two baseline ANC levels prior to CLOZARIL initiation. CLOZARIL initiation is not recommended in patients with BEN with an ANC less than 1000/μL. There are different ANC dosage modification recommendations in CLOZARIL-treated patients with BEN due to their lower baseline ANC levels. Table 2 provides recommendations on dosage modifications (dosage interruption and treatment discontinuation), based on ANC monitoring, during CLOZARIL treatment in patients with BEN and recommended frequency of ANC testing [see Dosage and Administration ( 2.4 )]. Management of CLOZARIL-Treated Patients Who Develop a Fever For patients who develop a fever during CLOZARIL treatment: • Interrupt CLOZARIL in those who develop a temperature of 101.3 °F (38.5 °C) or greater and obtain an ANC level. • If the ANC is less than 1000/μL in patients without BEN, initiate appropriate workup and treatment for infection. Refer to Table 1 or Table 2 for dosage modifications based on ANC monitoring [see Dosage and Administration ( 2.3 , 2.4 )]. In patients with fever and a normal neutrophil count, see Warnings and Precautions ( 5.11 ) for neuroleptic malignant syndrome and Warnings and Precautions ( 5.13 ) for fever. Restarting CLOZARIL in Patients Who Recovered from Severe Neutropenia Generally, do not rechallenge patients with CLOZARIL in those who experienced severe neutropenia. However, for some patients who had resolution of their CLOZARIL-related severe neutropenia after stopping CLOZARIL, the risk of schizophrenia exacerbation from not restarting CLOZARIL treatment may be greater than the risk of neutropenia reoccurrence from restarting CLOZARIL (e.g., patients who have no treatment options other than CLOZARIL). Concomitant Use of CLOZARIL with Other Drugs Known to Cause Neutropenia If CLOZARIL is used concomitantly with another drug known to cause neutropenia, consider more frequently ANC monitoring than the recommendations provided in Table 1 and Table 2 . 5.2 Orthostatic Hypotension, Bradycardia, and Syncope Hypotension, bradycardia, syncope, and cardiac arrest have occurred with clozapine treatment. The risk is highest during the initial titration period, particularly with rapid dose-escalation. These reactions can occur with the first dose, at doses as low as 12.5 mg. These reactions can be fatal. The syndrome is consistent with neurally mediated reflex bradycardia (NMRB). Treatment must begin at a maximum dose of 12.5 mg once daily or twice daily. The total daily dose can be increased in increments of 25 mg to 50 mg per day, if well-tolerated, to a target dose of 300 mg to 450 mg per day (administered in divided doses) by the end of 2 weeks. Subsequently, the dose can be increased weekly or twice weekly, in increments of up to 100 mg. The maximum dose is 900 mg per day. Use cautious titration and a divided dosage schedule to minimize the risk of serious cardiovascular reactions [see Dosage and Administration ( 2.2 )] . Consider reducing the dose if hypotension occurs. When restarting CLOZARIL in patients who have had even a brief interruption in treatment with CLOZARIL, the dosage must be reduced. This is necessary to minimize the risk of hypotension, bradycardia, and syncope [see Dosage and Administration (2.6 )]. Use CLOZARIL cautiously in patients with cardiovascular disease (history of myocardial infarction or ischemia, heart failure, or conduction abnormalities), cerebrovascular disease, and conditions which would predispose patients to hypotension (e.g., concomitant use of antihypertensives, dehydration and hypovolemia). 5.3 Falls CLOZARIL may cause somnolence, postural hypotension, motor and sensory instability, which may lead to falls and, consequently, fractures or other injuries. For patients with diseases, conditions, or medications that could exacerbate these effects, complete fall risk assessments when initiating antipsychotic treatment and recurrently for patients on long‑term antipsychotic therapy. 5.4 Seizures Seizure has been estimated to occur in association with clozapine use at a cumulative incidence at one year of approximately 5%, based on the occurrence of one or more seizures in 61 of 1743 patients exposed to clozapine during its clinical testing prior to domestic marketing (i.e., a crude rate of 3.5%). The risk of seizure is dose-related. Initiate treatment with a low dose (12.5…
Who should not take Clozaril
CLOZARIL is contraindicated in patients with a history of hypersensitivity to clozapine (e.g., photosensitivity, vasculitis, erythema multiforme, or Stevens-Johnson syndrome) or any other component of CLOZARIL [see Adverse Reactions ( 6.2 )]. Known hypersensitivity to clozapine or any other component of CLOZARIL. ( 4 )
Overdose — what happens if you take too much
Experience The most commonly reported signs and symptoms associated with clozapine overdose are: sedation, delirium, coma, tachycardia, hypotension, respiratory depression or failure; and hypersalivation. There are reports of aspiration pneumonia, cardiac arrhythmias, and seizure. Fatal overdoses have been reported with clozapine, generally at doses above 2500 mg. There have also been reports of patients recovering from overdoses well in excess of 4 g. 10.2 Management of Overdosage There is no available specific antidote to an overdose of CLOZARIL. Establish and maintain an airway; ensure adequate oxygenation and ventilation. Monitor cardiac status and vital signs. Use general symptomatic and supportive measures. Consider the possibility of multiple-drug involvement. Contact a Certified Poison Control Center for the most up to date information on the management of overdosage (1-800-222-1222). 10.1 Overdosage Experience The most commonly reported signs and symptoms associated with clozapine overdose are: sedation, delirium, coma, tachycardia, hypotension, respiratory depression or failure; and hypersalivation. There are reports of aspiration pneumonia, cardiac arrhythmias, and seizure. Fatal overdoses have been reported with clozapine, generally at doses above 2500 mg. There have also been reports of patients recovering from overdoses well in excess of 4 g. 10.2…
U.S. Poison Control: call or text 1-800-222-1222 (free, 24/7). In an emergency call 911. From the FDA label; not medical advice.
Interactions
Concomitant use of Strong CYP1A2 Inhibitors: Reduce CLOZARIL dose to one-third when coadministered with strong CYP1A2 inhibitors (e.g., fluvoxamine, ciprofloxacin, enoxacin). ( 2.7 , 7.1 ) • Concomitant use of Strong CYP3A4 Inducers is not recommended. ( 2.7 , 7.1 ) • Discontinuation of CYP1A2 or CYP3A4 Inducers: Consider reducing CLOZARIL dose when CYP1A2 inducers (e.g., tobacco smoke) or CYP3A4 inducers (e.g., carbamazepine) are discontinued. ( 2.7 , 7.1 ) • Anticholinergic drugs: Concomitant use may increase the risk for anticholinergic toxicity. ( 5.7 , 5.15 , 7.1 ) 7.1 Potential for Other Drugs to Affect CLOZARIL Clozapine is a substrate for many cytochrome P450 isozymes, in particular CYP1A2, CYP3A4, and CYP2D6. Use caution when administering CLOZARIL concomitantly with drugs that are inducers or inhibitors of these enzymes. CYP1A2 Inhibitors Concomitant use of CLOZARIL and CYP1A2 inhibitors can increase plasma levels of clozapine, potentially resulting in adverse reactions. Reduce the CLOZARIL dose to one-third of the original dose when CLOZARIL is coadministered with strong CYP1A2 inhibitors (e.g., fluvoxamine, ciprofloxacin, or enoxacin). The CLOZARIL dose should be increased to the original dose when coadministration of strong CYP1A2 inhibitors is discontinued [see Dosage and Administration ( 2.7 ), Clinical Pharmacology ( 12.3 )] . Moderate or weak CYP1A2 inhibitors include oral contraceptives and caffeine. Monitor patients closely when CLOZARIL is coadministered with these inhibitors. Consider reducing the CLOZARIL dosage if necessary [see Dosage and Administration ( 2.7 )] . CYP2D6 and CYP3A4 Inhibitors Concomitant treatment with CLOZARIL and CYP2D6 or CYP3A4 inhibitors (e.g., cimetidine, escitalopram, erythromycin, paroxetine, bupropion, fluoxetine, quinidine, duloxetine, terbinafine, or sertraline) can increase clozapine levels and lead to adverse reactions [see Clinical Pharmacology ( 12.3 )] . Use caution and monitor patients closely when using such inhibitors. Consider reducing the CLOZARIL dose [see Dosage and Administration ( 2.7 )] . CYP1A2 and CYP3A4 Inducers Concomitant treatment with drugs that induce CYP1A2 or CYP3A4 can decrease the plasma concentration of clozapine, resulting in decreased effectiveness of CLOZARIL. Tobacco smoke is a moderate inducer of CYP1A2. Strong CYP3A4 inducers include carbamazepine, phenytoin, St. John’s wort, and rifampin. It may be necessary to increase the CLOZARIL dose if used concomitantly with inducers of these enzymes. However, concomitant use of CLOZARIL and strong CYP3A4 inducers is not recommended [see Dosage and Administration ( 2.7 )] . Consider reducing the CLOZARIL dosage when discontinuing coadministered enzyme inducers; because discontinuation of inducers can result in increased clozapine plasma levels and an increased risk of adverse reactions [see Dosage and Administration ( 2.7 )] . Anticholinergic Drugs Concomitant treatment with clozapine and other drugs with anticholinergic activity (e.g., benztropine, cyclobenzaprine, diphenhydramine) can increase the risk for anticholinergic toxicity and severe gastrointestinal adverse reactions related to hypomotility. Avoid concomitant use of CLOZARIL with anticholinergic drugs when possible [see Warnings and Precautions ( 5.7 , 5.15 )] . Drugs that Cause QT Interval Prolongation Use caution when administering concomitant medications that prolong the QT interval or inhibit the metabolism of clozapine. Drugs that cause QT prolongation include: specific antipsychotics (e.g., ziprasidone, iloperidone, chlorpromazine, thioridazine, mesoridazine, droperidol, and pimozide), specific antibiotics (e.g., erythromycin, gatifloxacin, moxifloxacin, sparfloxacin), Class 1A antiarrhythmics (e.g., quinidine, procainamide) or Class III antiarrhythmics (e.g., amiodarone, sotalol), and others (e.g., pentamidine, levomethadyl acetate, methadone, halofantrine, mefloquine, dolasetron mesylate, probucol or tacrolimus) [see Warnings and Precautions ( 5.9 )] . 7.2 Potential for CLOZARIL to Affect Other Drugs Concomitant use of CLOZARIL with other drugs metabolized by CYP2D6 can increase levels of these CYP2D6 substrates. Use caution when coadministering CLOZARIL with other drugs that are metabolized by CYP2D6. It may be necessary to use lower doses of such drugs than usually prescribed. Such drugs include specific antidepressants, phenothiazines, carbamazepine, and Type 1C antiarrhythmics (e.g., propafenone, flecainide, and encainide). 7.1 Potential for Other Drugs to Affect CLOZARIL Clozapine is a substrate for many cytochrome P450 isozymes, in particular CYP1A2, CYP3A4, and CYP2D6. Use caution when administering CLOZARIL concomitantly with drugs that are inducers or inhibitors of these enzymes. CYP1A2 Inhibitors Concomitant use of CLOZARIL and CYP1A2 inhibitors can increase plasma levels of clozapine, potentially resulting in adverse reactions. Reduce the CLOZARIL dose to one-third of the original dose when CLOZARIL is coadministered with strong CYP1A2 inhibitors (e.g., fluvoxamine, ciprofloxacin, or enoxacin). The CLOZARIL dose should be increased to the original dose when coadministration of strong CYP1A2 inhibitors is discontinued [see Dosage and Administration ( 2.7 ), Clinical Pharmacology ( 12.3 )] . Moderate or weak CYP1A2 inhibitors include oral contraceptives and caffeine. Monitor patients closely when CLOZARIL is coadministered with these inhibitors. Consider reducing the CLOZARIL dosage if necessary [see Dosage and Administration ( 2.7 )] . CYP2D6 and CYP3A4 Inhibitors Concomitant treatment with CLOZARIL and CYP2D6 or CYP3A4 inhibitors (e.g., cimetidine, escitalopram, erythromycin, paroxetine, bupropion, fluoxetine, quinidine, duloxetine, terbinafine, or sertraline) can increase clozapine levels and lead to adverse reactions [see Clinical Pharmacology ( 12.3 )] . Use caution and monitor patients closely when using such inhibitors. Consider reducing the CLOZARIL dose [see Dosage and Administration ( 2.7 )] . CYP1A2 and CYP3A4 Inducers Concomitant treatment with drugs that induce CYP1A2 or CYP3A4 can decrease the plasma concentration of clozapine, resulting in decreased effectiveness of CLOZARIL. Tobacco smoke is a moderate inducer of CYP1A2. Strong CYP3A4 inducers include carbamazepine, phenytoin, St. John’s wort, and rifampin. It may be necessary to increase the CLOZARIL dose if used concomitantly with inducers of these enzymes. However, concomitant use of CLOZARIL and strong CYP3A4 inducers is not recommended [see Dosage and Administration ( 2.7 )] . Consider reducing the CLOZARIL dosage when discontinuing coadministered enzyme inducers; because discontinuation of inducers can result in increased clozapine plasma levels and an increased risk of adverse reactions [see Dosage and Administration ( 2.7 )] . Anticholinergic Drugs Concomitant treatment with clozapine and other drugs with anticholinergic activity (e.g., benztropine, cyclobenzaprine, diphenhydramine) can increase the risk for anticholinergic toxicity and severe gastrointestinal adverse reactions related to hypomotility. Avoid concomitant use of CLOZARIL with anticholinergic drugs when possible [see Warnings and Precautions ( 5.7 , 5.15 )] . Drugs that Cause QT Interval Prolongation Use caution when administering concomitant medications that prolong the QT interval or inhibit the metabolism of clozapine. Drugs that cause QT prolongation include: specific antipsychotics (e.g., ziprasidone, iloperidone, chlorpromazine, thioridazine, mesoridazine, droperidol, and pimozide), specific antibiotics (e.g., erythromycin, gatifloxacin, moxifloxacin, sparfloxacin), Class 1A antiarrhythmics (e.g., quinidine, procainamide) or Class III antiarrhythmics (e.g., amiodarone, sotalol), and others (e.g., pentamidine, levomethadyl acetate, methadone, halofantrine, mefloquine, dolasetron mesylate, probucol or tacrolimus) [see Warnings and Precautions ( 5.9 )] . 7.2 Potential for CLOZARIL to Affect Other Drugs Concomitant use of CLOZARIL with other drugs metabolized by CYP2D6 can increase levels of these CYP2D6 substrates. Use caution when coadministering CLOZARIL with other drugs that are metabolized by CYP2D6. It may be necessary to use lower doses of such drugs than usually prescribed. Such drugs include specific antidepressants, phenothiazines, carbamazepine, and Type 1C antiarrhythmics (e.g., propafenone, flecainide, and encainide).
How long does Clozapine stay in your body?
The elimination half-life of clozapine is about 12 hours at steady state (the label gives a mean elimination half-life of 12 hours, range 4 to 66 hours, after 100 mg twice daily); after a single 75 mg dose the mean is 8 hours (range 4 to 12 hours) — the time it takes the body to clear about half of it. As a rule of thumb, a medicine is mostly gone after roughly 4 to 5 half-lives, though this varies from person to person with age and kidney or liver function. The label reports two different elimination half-lives and says so explicitly: 8 hours mean after a single dose versus 12 hours mean at steady state, noting the half-life "increased significantly after multiple dosing," which it attributes to possible concentration-dependent pharmacokinetics. For someone taking clozapine regularly, the steady-state figure (mean 12 hours) is the applicable one, and the range around it is wide (4 to 66 hours) — individual variation is large. Metabolites: clozapine is almost completely metabolized before excretion, via CYP1A2, CYP2D6 and CYP3A4. Its main metabolite, desmethylclozapine (norclozapine), is described by the label as having "only limited activity," and the hydroxylated and N-oxide derivatives as inactive; the label does not state a half-life for any metabolite, so no metabolite half-life is reported here. Special populations: the label states that no specific pharmacokinetic studies were done in renal or hepatic impairment, but that "higher clozapine plasma concentrations are likely in patients with significant renal or hepatic impairment when given usual doses" — it gives no altered half-life number for them. It also flags CYP2D6 poor metabolizers (3-10% of people) as likely to reach higher-than-expected concentrations, and notes case reports where pneumonia or other inflammatory conditions raised clozapine levels. This is elimination pharmacokinetics only — not a drug-test detection window and not dosing guidance.
This is general information, not medical advice. It doesn’t tell you when a drug test would read negative (tests detect substances for different, often longer, windows) or when it’s safe to take another dose — ask your pharmacist or prescriber. Source: CLOZAPINE tablet, orally disintegrating — FDA Prescribing Information, §12.3 Pharmacokinetics (DailyMed).
Drug class
How this class works, per Atypical Antipsychotic Agents - StatPearls - NCBI Bookshelf.
May treat (source: NIH RxClass)
See how Clozaril ranks — best-rated atypical antipsychotic for:
Dosage forms
Tablet
The forms currently marketed in the U.S., per the FDA National Drug Code Directory.
Ways to save
Ask for the generic
Same active ingredient, far cheaper. Is there a generic? →
Request a 90-day supply
Bulk fills usually lower the per-dose price vs monthly refills.
Use copay cards
Manufacturer copay cards & patient-assistance programs — especially for brand drugs.
Compare alternatives
A same-class option may cost less. See alternatives →
Frequently asked questions
- What does Clozaril treat?
- Clozaril (Clozapine) may be used to treat bipolar disorder, psychotic disorders, schizophrenia, based on NIH RxClass drug-classification data (conditions a drug may treat — not a verbatim copy of the FDA-approved label). This is general reference, not medical advice.
- How does Clozaril work?
- Clozaril is a atypical antipsychotic. Atypical antipsychotics block dopamine D2 receptors and serotonin 5-HT2A receptors in the brain, rebalancing these signaling chemicals to reduce hallucinations, delusions, and mood symptoms in conditions like schizophrenia and bipolar disorder.
- How much does Clozaril cost?
- Nobody can tell you what you will pay — your price is set by your insurer's formulary, your deductible and the pharmacy's markup, and none of those are published. What IS published is what the pharmacy paid to acquire it: about $30.62 for 30, per the CMS NADAC survey. Treat that as the floor, not the quote — ask the pharmacist for the cash price as well as your copay, because for cheap generics the cash price often wins. Pharmacies pay less for a same-class option, Geodon — about $9.48 on the same basis.
- Is there a coupon or discount for Clozaril?
- pharmaranks is an independent ratings site, not a pharmacy — we don't issue coupons or sell Clozaril. To pay less, ask your prescriber or pharmacist whether a generic equivalent exists, check the manufacturer's copay/savings card and patient-assistance program, and compare a pharmacy discount card against your insurance copay. Prices vary by pharmacy, insurance, and location, so always confirm at the counter. This is general reference, not medical or financial advice.
- Who makes Clozaril?
- Clozaril is marketed by Heritage Life. You can see Heritage Life's full profile, rating, and other products on pharmaranks.
- Is Clozaril a brand-name or generic drug?
- Clozaril is a brand-name product with the active ingredient Clozapine. Lower-cost generic equivalents containing Clozapine are available — ask your pharmacist.
- Is Clozaril available over the counter?
- No. Clozaril is a prescription (Rx) medication in the US — you need a prescription from a licensed clinician (in person or via telehealth); it isn't sold over the counter. For some conditions there are OTC alternatives — ask your pharmacist.
- What forms does Clozaril come in?
- Clozaril is currently marketed as tablet, per the FDA's National Drug Code Directory.
- What class of drug is Clozaril?
- Clozaril is classified as atypical antipsychotic, per the FDA's Established Pharmacologic Class.
- Is Clozaril FDA-registered?
- Clozaril is on record with the U.S. FDA under application number NDA019758. You can verify this on its official FDA label.
- Is Clozaril safe?
- There's no single safe-or-not verdict, and we don't yet have a composite recall-safety score for Clozaril. Review its FDA-label side effects and warnings below, and always consult a licensed professional.
- What are the side effects of Clozaril?
- Clozaril's side effects are taken directly from its FDA label. From the label: The following adverse reactions are discussed in more detail in other sections of the labeling: • Severe Neutropenia [see Warnings and Precautions ( 5.1 )] • Orthostatic Hypotension, Bradycardia,… Both common and serious reactions are documented in full on this page. This is general reference from the FDA, not medical advice — always consult a professional.
Clinical content sourced from the FDA label via openFDA (U.S. FDA). View the FDA label on DailyMed → Provided for general reference only — not medical advice. Always consult a licensed professional and the current prescribing information.
Reviews
No reviews yet. Be the first to write one.
People also viewed
aristada
Aripiprazole Lauroxil
aristada initio kit
Aripiprazole Lauroxil
asenapine maleate
Asenapine Maleate
geodon
Ziprasidone Hydrochloride
invega
Paliperidone
invega hafyera
Paliperidone Palmitate
Compare Clozaril head-to-head
More atypical antipsychotic drugs
Browse medications A–Z
Research products from A to Z, compare independent ratings, and find alternatives.
clozaril
New