Overview
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: Clozapine Orally Disintegrating Tablets (referred to as Clozapine ODT) are available as peach, orally disintegrating tablets of 25 mg, 100 mg, 150 mg or 200 mg for oral administration without...
Mechanism of Action
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 ODT in schizophrenia is mediated through antagonism of the dopamine type 2 (D 2 ) and the serotonin type 2A (5-HT 2A ) 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 i 1.1 nM), adrenergic α 1A (K i 1.6 nM), serotonin 5-HT 6 (K i 4 nM ) , serotonin 5-HT 2A (K i 5.4 nM), muscarinic M 1 (K i 6.2 nM), serotonin 5-HT 7 (K i 6.3 nM), serotonin 5-HT 2C (K i 9.
Indications
- 1 INDICATIONS AND USAGE Clozapine orally disintegrating tablets (Clozapine ODT) is an atypical antipsychotic indicated for: 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 ODT should be used only in patients who have failed to respond adequately to standard antipsychotic treatment ( 1.
Common Doses
- 12.5 mg
- 25 mg
- 50 mg
- 150 mg
Dosage
2 DOSAGE AND ADMINISTRATION 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 at target dosage of 150 mg to 225 mg twice per day by the end of two weeks. ( 2.2 ) Subsequently may increase the doage 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. Clozapine ODT may be allowed to disintegrate or chewed, and may be taken with or without water.
Black Box Warning
WARNING: SEVERE NEUTROPENIA; ORTHOSTATIC HYPOTENSION, BRADYCARDIA, AND SYNCOPE; SEIZURE; MYOCARDITIS, PERICARDITIS, AND CARDIOMYOPATHY; INCREASED MORTALITY IN ELDERLY PATIENTS WITH DEMENTIA-RELATED PSYCHOSIS Severe Neutropenia Clozapine Orally Disintegrating Tablets (Clozapine ODT) have caused severe neutropenia which is associated with an increased risk of serious and fatal infections. Prior to initiating Clozapine ODT treatment, obtain baseline ANC(s).
Contraindications
- 4 CONTRAINDICATIONS Clozapine ODT 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 Clozapine ODT [see Adverse Reactions (6.2) ] . Known hypersensitivity to clozapine or any other component of Clozapine ODT ( 4 )
Side Effects
- 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 (5.2) ] 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.
Interactions
- 7 DRUG INTERACTIONS Concomitant use of Strong CYP1A2 Inhibitors : Reduce Clozapine ODT 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 Clozapine ODT dose when CYP1A2 (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.