PRINCIPAL DISPLAY PANEL - 200 mg Tablet Bottle Label

NDC 51862-903-01

Clozapine
Tablets, USP
200 mg

Rx Only
100 Tablets

mayne pharma

WARNING: SEVERE NEUTROPENIA; ORTHOSTATIC HYPOTENSION, BRADYCARDIA, AND

SYNCOPE; SEIZURE; MYOCARDITIS AND CARDIOMYOPATHY; INCREASED MORTALITY IN ELDERLY PATIENTS WITH DEMENTIA-RELATED PSYCHOSIS

See full prescribing information for complete boxed warning

*Severe Neutropenia: Clozapine tablets can cause severe neutropenia, which can lead to serious and fatal infections. Patients initiating and continuing treatment with Clozapine tablets must have a baseline blood absolute neutrophil count (ANC) measured before treatment initiation and regular ANC monitoring during treatment (2.1,5.1). *Clozapine tablets are available only through a restricted program called the Clozapine REMS (5.2). *Orthostatic Hypotension, Bradycardia, and Syncope: Risk is dose-related. Starting dose is 12.5 mg. Titrate gradually and use divided dosages (2.2,2.5,5.3). *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 (2.2,5.5). *Myocarditis, Cardiomyopathy, and Mitral Valve Incompetence: Can be fatal. Discontinue and obtain cardiac evaluation if findings suggest these cardiac reactions (5.6). *Increased Mortality in Elderly Patients with Dementia-Related Psychosis: Clozapine tablets are not approved for this condition (5.7).

1 INDICATIONS AND USAGE

1.1 Treatment-Resistant Schizophrenia

Clozapine tablets are indicated for the treatment of severely ill patients with schizophrenia who fail to respond adequately to standard antipsychotic treatment. Because of the risks of severe neutropenia and of seizure associated with its use, clozapine tablets should be used only in patients who have failed to respond adequately to standard antipsychotic treatment [see Warnings and Precautions (5.1, 5.5)].

The effectiveness of clozapine tablets in treatment-resistant schizophrenia was demonstrated in a 6-week, randomized, double-blind, active-controlled study comparing clozapine and chlorpromazine in patients who had failed other antipsychotics [see Clinical Studies (14.1)].

1.2 Reduction in the Risk of Recurrent Suicidal Behavior in Schizophrenia

or Schizoaffective Disorder

Clozapine tablets are indicated for reducing the risk of recurrent suicidal behavior in patients with schizophrenia or schizoaffective disorder who are judged to be at chronic risk for re-experiencing suicidal behavior, based on history and recent clinical state. Suicidal behavior refers to actions by a patient that put him/herself at risk for death.

The effectiveness of clozapine tablets in reducing the risk of recurrent suicidal behavior was demonstrated over a two-year treatment period in the InterSePT™ trial [see Clinical Studies (14.2)] .

4 CONTRAINDICATIONS

Clozapine tablets are contraindicated in patients with a history of serious hypersensitivity to clozapine (e.g., photosensitivity, vasculitis, erythema multiforme, or Stevens-Johnson Syndrome) or any other component of clozapine tablets [see Adverse Reactions (6.2)] .

6 ADVERSE REACTIONS

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 (5.3)].
• Falls [see Warnings and Precautions (5.4)].
• Seizures [see Warnings and Precautions (5.5)].
• Myocarditis, Cardiomyopathy, and Mitral Valve Incompetence [see Warnings and Precautions (5.6)].
• Increased Mortality in Elderly Patients with Dementia-Related Psychosis [see Warnings and Precautions (5.7)].
• Gastrointestinal Hypomotility with Severe Complications [See Warnings and Precautions (5.8)].
• Eosinophilia [see Warnings and Precautions (5.9)].
• QT Interval Prolongation [see Warnings and Precautions (5.10)].
• Metabolic Changes (Hyperglycemia and Diabetes Mellitus, Dyslipidemia, and Weight Gain) [see Warnings and Precautions (5.11)].
• Neuroleptic Malignant Syndrome [see Warnings and Precautions (5.12)].
• Hepatotoxicity [see Warnings and Precautions (5.13)].
• Fever [see Warnings and Precautions (5.14)].
• Pulmonary Embolism [see Warnings and Precautions (5.15)].
• Anticholinergic Toxicity [see Warnings and Precautions (5.16)].
• Interference with Cognitive and Motor Performance [see Warnings and Precautions (5.17)].
• Tardive Dyskinesia [see Warnings and Precautions (5.18)].
• Cerebrovascular Adverse Reactions [see Warnings and Precautions (5.19)].
• Recurrence of Psychosis and Cholinergic Rebound after Abrupt Discontinuation [see Warnings and Precautions (5.20)].

6.1 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 9 summarizes the most commonly reported adverse reactions (≥ 5%) in clozapine-treated patients (compared to chlorpromazine-treated patients) in the pivotal, 6- week, controlled trial in treatment-resistant schizophrenia.

Table 9. Common Adverse Reactions (≥ 5%) in the 6-Week, Randomized, Chlorpromazine-Controlled Trial in Treatment- Resistant Schizophrenia

Adverse Reaction	Clozapine (N = 126) (%)	Chlorpromazine (N = 142) (%)
Sedation	21	13
Tachycardia	17	11
Constipation	16	12
Dizziness	14	16
Hypotension	13	38
Fever (hyperthermia)	13	4
Hypersalivation	13	1
Hypertension	12	5
Headache	10	10
Nausea/vomiting	10	12
Dry mouth	5	20

Table 10 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 10. 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
Rate based on population of approximately 1700 exposed during premarket clinical evaluation of clozapine
Central Nervous System
Drowsiness/Sedation	39
Dizziness/Vertigo	19
Headache	7
Tremor	6
Syncope	6
Disturbed Sleep/Nightmares	4
Restlessness	4
Hypokinesia/Akinesia	4
Agitation	4
Seizures (convulsions)	3 *
Rigidity	3
Akathisia	3
Confusion	3
Fatigue	2
Insomnia	2
Cardiovascular
Tachycardia	25 *
Hypotension	9
Hypertension	4
Gastrointestinal
Constipation	14
Nausea	5
Abdominal Discomfort/Heartburn	4
Nausea/Vomiting	3
Vomiting	3
Diarrhea	2
Urogenital
Urinary Abnormalities	2
Autonomic Nervous System
Salivation	31
Sweating	6
Dry Mouth	6
Visual Disturbances	5
Skin
Rash	2
Hemic/Lymphatic
Leukopenia/Decreased WBC/Neutropenia	3
Miscellaneous
Fever	5
Weight Gain	4

Table 11 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 11. Incidence of Adverse Reactions in Patients Treated with Clozapine or Olanzapine in the InterSePT™ Study (≥10% in the Clozapine or Olanzapine group)

Adverse Reactions	Clozapine N = 479 % Reporting	Olanzapine N = 477 % Reporting
Salivary hypersecretion	48	6
Somnolence	46	25
Weight increased	31	56
Dizziness (excluding vertigo)	27	12
Constipation	25	10
Insomnia	20	33
Nausea	17	10
Vomiting	17	9
Dyspepsia	14	8

Dystonia

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.

6.2 Postmarketing Experience

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

Delirium, EEG abnormal, myoclonus, paresthesia, possible cataplexy, status epilepticus, obsessive compulsive symptoms, restless leg syndrome and post- discontinuation cholinergic rebound adverse reactions.

Cardiovascular System

Atrial or ventricular fibrillation, ventricular tachycardia, palpitations, QT interval prolongation, Torsades de Pointes, mitral valve incompetence associated with clozapine-related cardiomyopathy, myocardial infarction, cardiac arrest, myocarditis and periorbital edema.

Endocrine System

Pseudopheochromocytoma

Gastrointestinal System

Acute pancreatitis, dysphagia, salivary gland swelling, colitis, megacolon, intestinal ischemia or infarction.

Hepatobiliary System

Cholestasis, hepatitis, jaundice, hepatotoxicity, hepatic steatosis, hepatic necrosis, hepatic fibrosis, hepatic cirrhosis, liver injury (hepatic, cholestatic, and mixed), and liver failure.

Immune System Disorders

Angioedema, leukocytoclastic vasculitis.

Urogenital System

Acute interstitial nephritis, nocturnal enuresis, priapism, renal failure, and retrograde ejaculation.

Skin and Subcutaneous Tissue Disorders

Hypersensitivity reactions: photosensitivity, vasculitis, erythema multiforme, skin pigmentation disorder, and Stevens-Johnson Syndrome.

Musculoskeletal System and Connective Tissue Disorders

Myasthenic syndrome, rhabdomyolysis, and systemic lupus erythematosus.

Respiratory System

Aspiration, pleural effusion, pneumonia, lower respiratory tract infection, sleep apnea.

Hemic and Lymphatic System

Mild, moderate, or severe leukopenia, agranulocytosis, granulocytopenia, WBC decreased, deep-vein thrombosis, elevated hemoglobin/hematocrit, erythrocyte sedimentation rate (ESR) increased, sepsis, thrombocytosis, and thrombocytopenia.

Vision Disorders

Narrow-angle glaucoma

Miscellaneous

Creatine phosphokinase elevation, hyperuricemia, hyponatremia, polyserositis and weight loss.

7 DRUG INTERACTIONS

7.1 Potential for Other Drugs to Affect Clozapine

Clozapine is a substrate for many cytochrome P450 isozymes, in particular CYP1A2, CYP3A4, and CYP2D6. Use caution when administering clozapine concomitantly with drugs that are inducers or inhibitors of these enzymes.

CYP1A2 Inhibitors

Concomitant use of clozapine and CYP1A2 inhibitors can increase plasma levels of clozapine, potentially resulting in adverse reactions. Reduce the clozapine dose to one-third of the original dose when clozapine is coadministered with strong CYP1A2 inhibitors (e.g., fluvoxamine, ciprofloxacin, or enoxacin). The clozapine dose should be increased to the original dose when coadministration of strong CYP1A2 inhibitors is discontinued [see Dosage and Administration (2.6), Clinical Pharmacology (12.3)].

Moderate or weak CYP1A2 inhibitors include oral contraceptives and caffeine. Monitor patients closely when clozapine is coadministered with these inhibitors. Consider reducing the clozapine dosage if necessary [see Dosage and Administration (2.6)] .

CYP2D6 and CYP3A4 Inhibitors

Concomitant treatment with clozapine 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 clozapine dose [see Dosage and Administration (2.6)] .

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 clozapine. 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 clozapine dose if used concomitantly with inducers of these enzymes. However, concomitant use of clozapine and strong CYP3A4 inducers is not recommended [see Dosage and Administration (2.6)].

Consider reducing the clozapine 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 (2.6)].

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 clozapine with anticholinergic drugs when possible [see Warnings and Precautions (5.8, 5.16)] .

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 (5.10)] .

7.2 Potential for Clozapine to Affect Other Drugs

Concomitant use of clozapine with other drugs metabolized by CYP2D6 can increase levels of these CYPD26 substrates. Use caution when coadministering clozapine 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).

8 USE IN SPECIFIC POPULATIONS

8.1 Pregnancy

Risk Summary

There are no adequate or well-controlled studies of clozapine in pregnant women.

Reproduction studies have been performed in rats and rabbits at doses up to 0.4 and 0.9 times, respectively, the maximum recommended human dose (MRHD) of 900 mg/day on a mg/m 2body surface area basis. The studies revealed no evidence of impaired fertility or harm to the fetus due to clozapine. Because animal reproduction studies are not always predictive of human response, clozapine should be used during pregnancy only if clearly needed.

Clinical Considerations

Consider the risk of exacerbation of psychosis when discontinuing or changing treatment with antipsychotic medications during pregnancy and postpartum. Consider early screening for gestational diabetes for patients treated with antipsychotic medications [see Warnings and Precautions (5.11)] .

Neonates exposed to antipsychotic drugs during the third trimester of pregnancy are at risk for extrapyramidal and/or withdrawal symptoms following delivery. Monitor neonates for symptoms of agitation, hypertonia, hypotonia, tremor, somnolence, respiratory distress, and feeding difficulties. The severity of complications can vary from self-limited symptoms to some neonates requiring intensive care unit support and prolonged hospitalization.

Animal Data

In embryofetal developmental studies, clozapine had no effects on maternal parameters, litter sizes, or fetal parameters when administered orally to pregnant rats and rabbits during the period of organogenesis at doses up to 0.4 and 0.9 times, respectively, the MRHD of 900 mg/day on a mg/m 2body surface area basis.

In peri/postnatal developmental studies, pregnant female rats were administered clozapine over the last third of pregnancy and until day 21 postpartum. Observations were made on fetuses at birth and during the postnatal period; the offspring were allowed to reach sexual maturity and mated. Clozapine caused a decrease in maternal body weight but had no effects on litter size or body weights of either F1or F2 generations at doses up to 0.4 times the MRHD of 900 mg/day on a mg/m 2body surface area basis.

8.3 Nursing Mothers

Clozapine is present in human milk. Because of the potential for serious adverse reactions in nursing infants from clozapine, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.

8.4 Pediatric Use

Safety and effectiveness in pediatric patients have not been established.

8.5 Geriatric Use

There have not been sufficient numbers of geriatric patients in clinical studies utilizing clozapine to determine whether those over 65 years of age differ from younger subjects in their response to clozapine.

Orthostatic hypotension and tachycardia can occur with clozapine treatment [see Boxed Warningand Warnings and Precautions (5.3)]. Elderly patients, particularly those with compromised cardiovascular functioning, may be more susceptible to these effects.

Elderly patients may be particularly susceptible to the anticholinergic effects of clozapine, such as urinary retention and constipation [see Warnings and Precautions (5.16)].

Carefully select clozapine doses in elderly patients, taking into consideration their greater frequency of decreased hepatic, renal, or cardiac function, as well as other concomitant disease and other drug therapy. Clinical experience suggests that the prevalence of tardive dyskinesia appears to be highest among the elderly; especially elderly women [see Warnings and Precautions (5.18)].

8.6 Patients with Renal or Hepatic Impairment

Dose reduction may be necessary in patients with significant impairment of renal or hepatic function. Clozapine concentrations may be increased in these patients, because clozapine is almost completely metabolized and then excreted [see Dosage and Administration (2.7), Clinical Pharmacology (12.3)] .

8.7 CYP2D6 Poor Metabolizers

Dose reduction may be necessary in patients who are CYP2D6 poor metabolizers. Clozapine concentrations may be increased in these patients, because clozapine is almost completely metabolized and then excreted [see Dosage and Administration (2.7), Clinical Pharmacology (12.3)] .

8.8 Hospice Patients

For hospice patients (i.e., terminally ill patients with an estimated life expectancy of six months or less), the prescriber may reduce the ANC monitoring frequency to once every 6 months, after a discussion with the patient and his/her caregiver. Individual treatment decisions should weigh the importance of monitoring ANC in the context of the need to control psychiatric symptoms and the patient's terminal illness.

2 DOSAGE AND ADMINISTRATION

2.1 Required Laboratory Testing Prior to Initiation and During Therapy

Prior to initiating treatment with clozapine tablets, a baseline ANC must be obtained. The baseline ANC must be at least 1500/µL for the general population, and at least 1000/µL for patients with documented Benign Ethnic Neutropenia (BEN). To continue treatment, the ANC must be monitored regularly [see Warnings and Precautions (5.1)].

2.2 Dosing Information

The starting dose is 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 achieve 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 once weekly or twice weekly, in increments of up to 100 mg. The maximum dose is 900 mg per day. To minimize the risk of orthostatic hypotension, bradycardia, and syncope, it is necessary to use this low starting dose, gradual titration schedule, and divided dosages [see Warnings and Precautions (5.3)].

Clozapine tablets can be taken with or without food [see Pharmacokinetics (12.3)].

2.3 Maintenance Treatment

Generally, patients responding to clozapine tablets should continue maintenance treatment on their effective dose beyond the acute episode.

2.4 Discontinuation of Treatment

Method of treatment discontinuation will vary depending on the patient's last ANC:

• See Tables 2or 3for appropriate ANC monitoring based on the level of neutropenia if abrupt treatment discontinuation is necessary because of moderate to severe neutropenia.
• Reduce the dose gradually over a period of 1 to 2 weeks if termination of clozapine tablets therapy is planned and there is no evidence of moderate to severe neutropenia.
• For abrupt clozapine discontinuation for a reason unrelated to neutropenia, continuation of the existing ANC monitoring is recommended for general population patients until their ANC is ≥1500/µL and for BEN patients until their ANC is ≥1000/µL or above their baseline.
• Additional ANC monitoring is required for any patient reporting onset of fever (temperature of 38.5°C or 101.3°F, or greater) during the 2 weeks after discontinuation [see Warnings and Precautions (5.1)].
• Monitor all patients carefully for the recurrence of psychotic symptoms and symptoms related to cholinergic rebound such as profuse sweating, headache, nausea, vomiting, and diarrhea.

2.5 Re-Initiation of Treatment

When restarting clozapine tablets in patients who have discontinued clozapine tablets (i.e., 2 days or more since the last dose), re-initiate with 12.5 mg once daily or twice daily. This is necessary to minimize the risk of hypotension, bradycardia, and syncope [see Warnings and Precautions (5.3)]. If that dose is well-tolerated, the dose may be increased to the previously therapeutic dose more quickly than recommended for initial treatment.

2.6 Dosage Adjustments with Concomitant use of CYP1A2, CYP2D6, CYP3A4

Inhibitors or CYP1A2, CYP3A4 Inducers

Dose adjustments may be necessary in patients with concomitant use of: strong CYP1A2 inhibitors (e.g., fluvoxamine, ciprofloxacin, or enoxacin); moderate or weak CYP1A2 inhibitors (e.g., oral contraceptives, or caffeine); CYP2D6 or CYP3A4 inhibitors (e.g., cimetidine, escitalopram, erythromycin, paroxetine, bupropion, fluoxetine, quinidine, duloxetine, terbinafine, or sertraline); CYP3A4 inducers (e.g., phenytoin, carbamazepine, St. John's wort, and rifampin); or CYP1A2 inducers (e.g., tobacco smoking) (Table 1) [see Drug Interactions (7)].

Table 1. Dose Adjustment in Patients Taking Concomitant Medications

Co- medications	Scenarios
	Initiating clozapine tablets while taking a co-medication	Adding a co- medication while taking clozapine tablets	Discontinuing a co- medication while continuing clozapine tablets
Strong CYP1A2 Inhibitors	Use one-third of the clozapine tablet dose.	Increase clozapine tablet dose based on clinical response.
Moderate or Weak CYP1A2 Inhibitors	Monitor for adverse reactions. Consider reducing the clozapine tablet dose if necessary.	Monitor for lack of effectiveness. Consider increasing clozapine tablet dose if necessary.
CYP2D6 or CYP3A4 Inhibitors
Strong CYP3A4 Inducers	Concomitant use is not recommended. However, if the inducer is necessary, it may be necessary to increase the clozapine tablet dose. Monitor for decreased effectiveness.	Reduce clozapine tablet dose based on clinical response.
Moderate or weak CYP1A2 or CYP3A4 Inducers	Monitor for decreased effectiveness. Consider increasing the clozapine tablet dose if necessary.	Monitor for adverse reactions. Consider reducing the clozapine tablet dose if necessary.

2.7 Renal or Hepatic Impairment, or CYP2D6 Poor Metabolizers

It may be necessary to reduce the clozapine tablet dose in patients with significant renal or hepatic impairment, or in CYP2D6 poor metabolizers [see Use in Specific Populations (8.6, 8.7)].

3 DOSAGE FORMS AND STRENGTHS

Clozapine tablets are available as 25 mg, 50 mg, and 100 mg round, pale- yellow, uncoated tablets with a facilitated score on one side and as a 200 mg oval shape, pale-yellow, uncoated tablet with a facilitated score on one side.

11 DESCRIPTION

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:

C18H19ClN4 Mol. wt. 326.83

Clozapine tablets are available in pale yellow tablets of 25 mg, 50 mg, 100 mg, and 200 mg for oral administration.

Active Ingredient: clozapine

Inactive Ingredients are colloidal silicon dioxide, lactose, magnesium stearate, povidone, starch (corn), sodium starch glycolate, and talc.

12 CLINICAL PHARMACOLOGY

12.1 Mechanism of Action

The mechanism of action of clozapine is unknown. However, it has been proposed that the therapeutic efficacy of clozapine in schizophrenia is mediated through antagonism of the dopamine type 2 (D 2) and the serotonin type 2A (5-HT2A) receptors. Clozapine also acts as an antagonist at adrenergic, cholinergic, histaminergic and other dopaminergic and serotonergic receptors.

12.2 Pharmacodynamics

Clozapine demonstrated binding affinity to the following receptors: histamine H 1(K i1.1 nM), adrenergic α 1A(K i1.6 nM), serotonin 5-HT 6(K i4 nM), serotonin 5-HT 2A(K i5.4 nM), muscarinic M 1(K i6.2 nM), serotonin 5-HT 7(K i6.3 nM), serotonin 5-HT 2C(K i9.4 nM), dopamine D 4(K i24 nM), adrenergic α 2A(K i90 nM), serotonin 5-HT 3(K i95 nM), serotonin 5-HT 1A(K i120 nM), dopamine D 2(K i160 nM), dopamine D 1(K i270 nM), dopamine D 5(K i454 nM), and dopamine D 3(K i555 nM).

Clozapine causes little or no prolactin elevation.

Clinical electroencephalogram (EEG) studies demonstrated that clozapine increases delta and theta activity and slows dominant alpha frequencies. Enhanced synchronization occurs. Sharp wave activity and spike and wave complexes may also develop. Patients have reported an intensification of dream activity during clozapine therapy. REM sleep was found to be increased to 85% of the total sleep time. In these patients, the onset of REM sleep occurred almost immediately after falling asleep.

12.3 Pharmacokinetics

Absorption

In humans, clozapine tablets (25 mg and 100 mg) are equally bioavailable relative to a clozapine solution. Following oral administration of clozapine 100 mg twice daily, the average steady-state peak plasma concentration was 319 ng/mL (range: 102 to 771 ng/mL), occurring at the average of 2.5 hours (range: 1 to 6 hours) after dosing. The average minimum concentration at steady state was 122 ng/mL (range: 41 to 343 ng/mL), after 100 mg twice daily dosing. Food does not appear to affect the systemic bioavailability of clozapine. Thus, clozapine may be administered with or without food.

Distribution

Clozapine is approximately 97% bound to serum proteins. The interaction between clozapine and other highly protein-bound drugs has not been fully evaluated but may be important [see Drug Interactions (7)].

Metabolism and Excretion

Clozapine is almost completely metabolized prior to excretion, and only trace amounts of unchanged drug are detected in the urine and feces. Clozapine is a substrate for many cytochrome P450 isozymes, in particular CYP1A2, CYP2D6, and CYP3A4. Approximately 50% of the administered dose is excreted in the urine and 30% in the feces. The demethylated, hydroxylated, and N-oxide derivatives are components in both urine and feces. Pharmacological testing has shown the desmethyl metabolite (norclozapine) to have only limited activity, while the hydroxylated and N-oxide derivatives were inactive. The mean elimination half- life of clozapine after a single 75 mg dose was 8 hours (range: 4 to 12 hours), compared to a mean elimination half-life of 12 hours (range: 4 to 66 hours), after achieving steady state with 100 mg twice daily dosing.

A comparison of single-dose and multiple-dose administration of clozapine demonstrated that the elimination half-life increased significantly after multiple dosing relative to that after single-dose administration, suggesting the possibility of concentration-dependent pharmacokinetics. However, at steady state, approximately dose-proportional changes with respect to AUC (area under the curve), peak, and minimum clozapine plasma concentrations were observed after administration of 37.5, 75, and 150 mg twice daily.

Drug-Drug Interaction Studies

Fluvoxamine

A pharmacokinetic study was conducted in 16 schizophrenic patients who received clozapine under steady-state conditions. After coadministration of fluvoxamine for 14 days, mean trough concentrations of clozapine and its metabolites, N-desmethylclozapine and clozapine N-oxide, were elevated about three-fold compared to baseline steady-state concentrations.

Paroxetine, Fluoxetine, and Sertraline

In a study of schizophrenic patients (n=14) who received clozapine under steady-state conditions, coadministration of paroxetine produced only minor changes in the levels of clozapine and its metabolites. However, other published reports describe modest elevations (less than two-fold) of clozapine and metabolite concentrations when clozapine was taken with paroxetine, fluoxetine, and sertraline.

Specific Population Studies

Renal or Hepatic Impairment

No specific pharmacokinetic studies were conducted to investigate the effects of renal or hepatic impairment on the pharmacokinetics of clozapine. Higher clozapine plasma concentrations are likely in patients with significant renal or hepatic impairment when given usual doses.

CYP2D6 Poor Metabolizers

A subset (3% to 10%) of the population has reduced activity of CYP2D6 (CYP2D6 poor metabolizers). These individuals may develop higher than expected plasma concentrations of clozapine when given usual doses.

13 NONCLINICAL TOXICOLOGY

13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility

Carcinogenesis

No carcinogenic potential was demonstrated in long-term studies in mice and rats at doses up to 0.3 times and 0.4 times, respectively, the maximum recommended human dose (MRHD) of 900 mg/day on a mg/m 2body surface area basis.

Mutagenesis

Clozapine was not genotoxic when tested in the following gene mutation and chromosomal aberration tests: the bacterial Ames test, the in vitromammalian V79 in Chinese hamster cells, the in vitrounscheduled DNA synthesis in rat hepatocytes or the in vivomicronucleus assay in mice.

Impairment of Fertility

Clozapine had no effect on any parameters of fertility, pregnancy, fetal weight or postnatal development when administered orally to male rats 70 days before mating and to female rats for 14 days before mating at doses up to 0.4 times the MRHD of 900 mg/day on a mg/m 2body surface area basis.

14 CLINICAL STUDIES

14.1 Treatment-Resistant Schizophrenia

The efficacy of clozapine in treatment-resistant schizophrenia was established in a multicenter, randomized, double-blind, active-controlled (chlorpromazine) study in patients with a DSM-III diagnosis of schizophrenia who had inadequate responses to at least 3 different antipsychotics (from at least 2 different chemical classes) during the preceding 5 years. The antipsychotic trials must have been judged adequate; the antipsychotic dosages must have been equivalent to or greater than 1000 mg per day of chlorpromazine for a period of at least 6 weeks, each without significant reduction of symptoms. There must have been no period of good functioning within the preceding 5 years. Patients must have had a baseline score of at least 45 on the investigator-rated Brief Psychiatric Rating Scale (BPRS). On the 18-item BPRS, 1 indicates the absence of symptoms, and 7 indicates severe symptoms; the maximum potential total BPRS score is 126. At baseline, the mean BPRS score was 61. In addition, patients must have had a score of at least 4 on at least two of the following four individual BPRS items: conceptual disorganization, suspiciousness, hallucinatory behavior, and unusual thought content. Patients must have had a Clinical Global Impressions – Severity Scale score of at least 4 (moderately ill).

In the prospective, lead-in phase of the trial, all patients (N=305) initially received single-blind treatment with haloperidol (the mean dose was 61 mg per day) for 6 weeks. More than 80% of patients completed the 6-week trial. Patients with an inadequate response to haloperidol (n=268) were randomized to double-blind treatment with clozapine (N=126) or chlorpromazine (N=142). The maximum daily clozapine dose was 900 mg; the mean daily dose was >600 mg). The maximum daily chlorpromazine dose was 1800 mg; the mean daily dose was >1200 mg.

The primary endpoint was treatment response, predefined as a decrease in BPRS score of at least 20% and either (1) a CGI-S score of ≤3 (mildly ill), or (2) a BPRS score of ≤ 35, at the end of 6 weeks of treatment. Approximately 88% of patients from the clozapine and chlorpromazine groups completed the 6-week trial. At the end of 6 weeks, 30% of the clozapine group responded to treatment, and 4% of the chlorpromazine group responded to treatment. The difference was statistically significant (p < 0.001). The mean change in total BPRS score was - 16 and -5 in the clozapine and chlorpromazine group, respectively; the mean change in the 4 key BPRS item scores was -5 and -2 in the clozapine and chlorpromazine group, respectively; and the mean change in CGI-S score was -1.2 and -0.4, in the clozapine and chlorpromazine group, respectively. These changes in the clozapine group were statistically significantly greater than in the chlorpromazine group (p < 0.001 in each analysis).

14.2 Recurrent Suicidal Behavior in Schizophrenia or Schizoaffective

Disorder

The effectiveness of clozapine in reducing the risk of recurrent suicidal behavior was assessed in the International Suicide Prevention Trial (InterSePT™, a trademark of Novartis Pharmaceuticals Corporation). This was a prospective, randomized, open-label, active-controlled, multicenter, international, parallel-group comparison of clozapine versus olanzapine (Zyprexa®, a registered trademark of Eli Lilly and Company) in 956 patients with schizophrenia or schizoaffective disorder (DSM-IV) who were judged to be at risk for recurrent suicidal behavior. Only about one-fourth of these patients (27%) were considered resistant to standard antipsychotic drug treatment. To enter the trial, patients must have met 1 of the following criteria:

• They had attempted suicide within the three years prior to their baseline evaluation.
• They had been hospitalized to prevent a suicide attempt within the three years prior to their baseline evaluation.
• They demonstrated moderate-to-severe suicidal ideation with a depressive component within one week prior to their baseline evaluation.
• They demonstrated moderate-to-severe suicidal ideation accompanied by command hallucinations to do self-harm within one week prior to their baseline evaluation.

Dosing regimens for each treatment group were determined by individual investigators and were individualized by patient. Dosing was flexible, with a dose range of 200 to 900 mg/day for clozapine and 5 to 20 mg/day for olanzapine. For the 956 patients who received clozapine or olanzapine in this study, there was extensive use of concomitant psychotropics: 84% with antipsychotics, 65% with anxiolytics, 53% with antidepressants, and 28% with mood stabilizers. There was significantly greater use of concomitant psychotropic medications among the patients in the olanzapine group.

The primary efficacy measure was time to (1) a significant suicide attempt, including a completed suicide; (2) hospitalization due to imminent suicide risk, including increased level of surveillance for suicidality for patients already hospitalized; or (3) worsening of suicidality severity as demonstrated by "much worsening" or "very much worsening" from baseline in the Clinical Global Impression of Severity of Suicidality as assessed by the Blinded Psychiatrist (CGI-SS-BP) scale. A determination of whether or not a reported event met criterion 1 or 2 above was made by the Suicide Monitoring Board (SMB), a group of experts blinded to patient data.

A total of 980 patients were randomized to the study and 956 received study medication. Sixty-two percent of the patients were diagnosed with schizophrenia, and the remainder (38%) were diagnosed with schizoaffective disorder. Only about one-fourth of the total patient population (27%) was identified as "treatment-resistant" at baseline. There were more males than females in the study (61% of all patients were male). The mean age of patients entering the study was 37 years of age (range 18 to 69). Most patients were Caucasian (71%), 15% were Black, 1% were Asian, and 13% were classified as being of "other" races.

Patients treated with clozapine had a statistically significant longer delay in the time to recurrent suicidal behavior in comparison with olanzapine. This result should be interpreted only as evidence of the effectiveness of clozapine in delaying time to recurrent suicidal behavior and not a demonstration of the superior efficacy of clozapine over olanzapine.

The probability of experiencing (1) a significant suicide attempt, including a completed suicide, or (2) hospitalization because of imminent suicide risk, including increased level of surveillance for suicidality for patients already hospitalized, was lower for clozapine patients than for olanzapine patients at Week 104: clozapine 24% versus olanzapine 32%; 95% CI of the difference: 2%, 14% (Figure 1).

Figure 1. Cumulative Probability of a Significant Suicide Attempt or Hospitalization to Prevent Suicide in Patients with Schizophrenia or Schizoaffective Disorder at High Risk of Suicidality

17 PATIENT COUNSELING INFORMATION

Discuss the following issues with patients and caregivers:

• Severe Neutropenia:

  • Instruct patients (and caregivers) beginning treatment with clozapine tablets about the risk of developing severe neutropenia and infection.
  • Instruct patients to immediately report to their physician any symptom or sign of infection (e.g., flu- like illness; fever; lethargy; general weakness or malaise; mucus membrane ulceration; skin, pharyngeal, vaginal, urinary, or pulmonary infection; or extreme weakness or lethargy) occurring at any time during clozapine tablet therapy, to aid in evaluation for neutropenia and to institute prompt and appropriate management. [see Warnings and Precautions (5.1), (5.12), and (5.14)] .
  • Inform patients and caregivers clozapine tablets are available only through a restricted program called the Clozapine REMS Program designed to ensure the required blood monitoring, in order to reduce the risk of developing severe neutropenia. Advise patients and caregivers of the importance of having blood tested as follows:
    • Weekly blood tests are required for the first 6 months.
    • An ANC is required every 2 weeks for the next 6 months if an acceptable ANC is maintained during the first 6 months of continuous therapy,
    • An ANC is required once every 4 weeks thereafter if an acceptable ANC is maintained during the second 6 months of continuous therapy.
  • Clozapine tablets are available only from certified pharmacies participating in the program.
    Provide patients (and caregivers) with website information and the telephone number on how to obtain the product (www.clozapinerems.com or 1-844-267-8678) [ see Warnings and Precautions (5.2)].

• Orthostatic Hypotension, Bradycardia, and Syncope: Inform patients and caregivers about the risk of orthostatic hypotension and syncope, especially during the period of initial dose titration. Instruct them to strictly follow the clinician's instructions for dosage and administration. Advise patients to consult their clinician immediately if they feel faint, lose consciousness or have signs or symptoms suggestive of bradycardia or arrhythmia [see Dosage and Administration (2.2)and Warnings and Precautions (5.3)].

• Seizures:Inform patients and caregivers about the significant risk of seizure during clozapine tablet treatment. Caution them about driving and any other potentially hazardous activity while taking clozapine tablets [see Warnings and Precautions (5.5)].

• Gastrointestinal Hypomotility with Severe Complications:Educate patients and caregivers on the risks, prevention and treatment of clozapine-induced constipation, including medications to avoid when possible (e.g., drugs with anticholinergic activity). Encourage appropriate hydration, physical activity, and fiber intake and emphasize that prompt attention and treatment to the development of constipation or other gastrointestinal symptoms is critical in preventing severe complications. Advise patients and caregivers to contact their health care provider if they experience symptoms of constipation (e.g., difficulty passing stools, incomplete passage of stool, decreased bowel movement frequency) or other symptoms associated with gastrointestinal hypomotility (e.g., nausea, abdominal distension or pain, vomiting) [see Warnings and Precautions (5.8), Drug Interactions (7.1)] .

• QT Interval Prolongation:Advise patients to consult their clinician immediately if they feel faint, lose consciousness or have signs or symptoms suggestive of arrhythmia. Instruct patients to not take clozapine tablets with other drugs that cause QT interval prolongation. Instruct patients to inform their clinicians that they are taking clozapine tablets before any new drug [see Warnings and Precautions (5.10.)and Drug Interactions (7.1)].

• Metabolic Changes (hyperglycemia and diabetes mellitus, dyslipidemia, weight gain):Educate patients and caregivers about the risk of metabolic changes and the need for specific monitoring. The risks include hyperglycemia and diabetes mellitus, dyslipidemia, weight gain, and cardiovascular reactions. Educate patients and caregivers about the symptoms of hyperglycemia (high blood sugar) and diabetes mellitus (e.g., polydipsia, polyuria, polyphagia, and weakness). Monitor all patients for these symptoms. Patients who are diagnosed with diabetes or have risk factors for diabetes (obesity, family history of diabetes) should have their fasting blood glucose monitored before beginning treatment and periodically during treatment. Patients who develop symptoms of hyperglycemia should have assessments of fasting glucose. Clinical monitoring of weight is recommended [see Warnings and Precautions (5.11)] .

• Interference with Cognitive and Motor Performance:Because clozapine tablets may have the potential to impair judgment, thinking, or motor skills, patients should be cautioned about operating hazardous machinery, including automobiles, until they are reasonably certain that clozapine tablets therapy does not affect them adversely [see Warnings and Precautions (5.17)] . Missed Doses and Re-initiating Treatment:Inform patients and caregivers that if the patient misses taking clozapine tablets for more than 2 days, they should not restart their medication at the same dosage but should contact their physician for dosing instructions [see Dosage and Administration (2.5)and Warnings and Precautions (5.1, 5.3)].

• Pregnancy:Patients and caregivers should notify the clinician if the patient becomes pregnant or intends to become pregnant during therapy [see Use in Specific Populations (8.1)].

• Nursing:Advise patients and caregivers that the patient should not breastfeed an infant if they are taking clozapine tablets [see Use in Specific Populations (8.3)].

• Concomitant Medication:Advise patients to inform their healthcare provider if they are taking, or plan to take, any prescription or over-the-counter drugs; there is a potential for significant drug-drug interactions [see Dosage and Administration (2.6), Drug Interactions (7.1).

*Zyprexa® (olanzapine) is a registered trademark of Eli Lilly and Company.

Manufactured by:
Mayne Pharma
Greenville, NC 27834
Revised: May 2021

61848

10 OVERDOSAGE

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 Management of Overdosage

There is no available specific antidote to an overdose of clozapine. 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).

16 HOW SUPPLIED/STORAGE AND HANDLING

16.1 How Supplied

Clozapine tablets are available as 25 mg, 50 mg, and 100 mg round, pale- yellow, tablets with a score on one side and as a 200 mg oval shape, pale- yellow tablet with a score on one side.

Clozapine Tablets

25 mg

Engraved with "MYX" above score and "25" below score. Engraved with "900" on other side.

Bottle of 100	NDC 51862-900-01
Bottle of 500	NDC 51862-900-05

50 mg

Engraved with "MYX" above score and "50" below score. Engraved with "901" on other side.

Bottle of 100	NDC 51862-901-01
Bottle of 500	NDC 51862-901-05

100 mg

Engraved with "MYX" above score and "100" below score. Engraved with "902" on other side.

Bottle of 100	NDC 51862-902-01
Bottle of 500	NDC 51862-902-05

200 mg

Engraved with "MYX" left of score and "200" right of score. Engraved with "903" on other side**.**

Bottle of 100	NDC 51862-903-01
Bottle of 500	NDC 51862-903-05

16.2 Storage and Handling

Store at 20° to 25°C (68° to 77°F). [See USP Controlled Room Temperature]. Keep out of reach of children.