INDICATIONS AND USAGE
Treatment Resistant Schizophrenia
CLOZARIL is indicated for the treatment of severely ill patients with schizophrenia who fail to respond adequately to standard antipsychotic treatment. Because of the significant risk of agranulocytosis and seizure associated with its use, CLOZARIL should be used only in patients who have failed to respond adequately to standard antipsychotic treatment.
[see Warnings and Precautions (5.1, 5.4)]
The effectiveness of CLOZARIL in treatment-resistant schizophrenia was demonstrated in a 6-week, randomized, double-blind, active-controlled study comparing CLOZARIL and chlorpromazine in patients who had failed other antipsychotics.
[see Clinical Studies]
Reduction in the Risk of Recurrent Suicidal Behavior in Schizophrenia or Schizoaffective Disorder
CLOZARIL is 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 CLOZARIL in reducing the risk of recurrent suicidal behavior was demonstrated over a 2-year treatment period in the InterSePT trial.
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[see Clinical Studies]
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DOSAGE AND ADMINISTRATION
Required Laboratory Testing Prior to Initiation and During Therapy
Prior to initiating treatment with CLOZARIL, obtain a complete blood count (CBC) with differential. The absolute neutrophil count (ANC) must be greater than or equal to 2000/mm and the WBC must be greater than or equal to 3500 mm in order to initiate treatment. To continue treatment, the ANC and WBC must be monitored regularly.
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[see Warnings and Precautions]
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]
CLOZARIL can be taken with or without food.
[see Pharmacokinetics]
Maintenance Treatment
Generally, it is recommended that patients responding to CLOZARIL continue maintenance treatment on their effective dose beyond the acute episode.
Discontinuation of Treatment
In the event of planned termination of CLOZARIL therapy, reduce the dose gradually over a period of 1 to 2 weeks. If abrupt discontinuation is necessary (because of agranulocytosis or another medical condition, for example), monitor carefully for the recurrence of psychotic symptoms and symptoms related to cholinergic rebound such as profuse sweating, headache, nausea, vomiting, and diarrhea.
Re-Initiation of Treatment
When restarting CLOZARIL in patients who have discontinued CLOZARIL (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. If that dose is well tolerated, the dose may be increased to the previously therapeutic dose more quickly than recommended for initial treatment.
[see Warnings and Precautions]
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]
Table 1. Dose Adjustment in Patients Taking Concomitant Medications
Comedications
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Scenarios
|
| Initiating CLOZARIL while taking a comedication |
Adding a comedication while taking CLOZARIL |
Discontinuing a comedication while continuing CLOZARIL |
Strong CYP1A2 Inhibitors |
Use one-third of the CLOZARIL dose. |
Increase CLOZARIL dose based on clinical response. |
Moderate or Weak CYP1A2 Inhibitors |
Monitor for adverse reactions. Consider reducing the CLOZARIL dose if necessary.
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Monitor for lack of effectiveness. Consider increasing CLOZARIL dose if necessary. |
CYP2D6 or CYP3A4 Inhibitors |
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Strong CYP3A4 Inducers |
Concomitant use is not recommended. However, if the inducer is necessary, it may be necessary to increase the CLOZARIL dose. Monitor for decreased effectiveness.
|
Reduce CLOZARIL dose based on clinical response. |
Moderate or weak CYP1A2 or CYP3A4 Inducers |
Monitor for decreased effectiveness. Consider increasing the CLOZARIL dose if necessary. |
Monitor for adverse reactions. Consider reducing the CLOZARIL dose if necessary.
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Renal or Hepatic Impairment or CYP2D6 Poor Metabolizers
It may be necessary to reduce the CLOZARIL dose in patients with significant renal or hepatic impairment, or in CYP2D6 poor metabolizers.
[see Use in Specific Populations (8.6, 8.7)]
DOSAGE FORMS AND STRENGTHS
CLOZARIL (clozapine) is available as 25 mg and 100 mg round, pale-yellow, uncoated tablets with a facilitated score on one side.
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