Overview
11 DESCRIPTION Olanzapine is an atypical antipsychotic that belongs to the thienobenzodiazepine class. The chemical designation is 2-methyl-4-(4-methyl-1-piperazinyl)-10 H -thieno[2,3- b ] [1,5]benzodiazepine. The molecular formula is C 17 H 20 N 4 S, which corresponds to a molecular weight of 312.44.
Mechanism of Action
12 CLINICAL PHARMACOLOGY 12.1 Mechanism of Action The mechanism of action of olanzapine, in the listed indications is unclear. However, the efficacy of olanzapine in schizophrenia could be mediated through a combination of dopamine and serotonin type 2 (5HT2) antagonism. 12.2 Pharmacodynamics Olanzapine binds with high affinity to the following receptors: serotonin 5HT 2A/2C , 5HT 6 (K i =4, 11, and 5 nM, respectively), dopamine D 1-4 (K i =11-31 nM), histamine H 1 (K i =7 nM), and adrenergic α 1 receptors (K i =19 nM). Olanzapine is an antagonist with moderate affinity binding for serotonin 5HT 3 (K i =57 nM) and muscarinic M 1-5 (K i =73, 96, 132, 32, and 48 nM, respectively). Olanzapine binds with low affinity to GABA A , BZD, and β-adrenergic receptors (K i >10 μM). 12.
Indications
- 1 INDICATIONS AND USAGE Olanzapine is an atypical antipsychotic indicated: As oral formulation for the: Treatment of schizophrenia. ( 1.1 ) Adults: Efficacy was established in three clinical trials in patients with schizophrenia: two 6-week trials and one maintenance trial. ( 14.1 ) Adolescents (ages 13-17): Efficacy was established in one 6-week trial in patients with schizophrenia ( 14.1 ). The increased potential (in adolescents compared with adults) for weight gain and dyslipidemia may lead clinicians to consider prescribing other drugs first in adolescents. ( 1.
Common Doses
- 5 mg
- 10 mg
- 2.5 mg
- 15 mg
Dosage
2 DOSAGE AND ADMINISTRATION Schizophrenia in adults ( 2.1 ) Oral: Start at 5 mg to 10 mg once daily; Target: 10 mg/day within several days Schizophrenia in adolescents ( 2.1 ) Oral: Start at 2.5 mg to 5 mg once daily; Target: 10 mg/day Bipolar I Disorder (manic or mixed episodes) in adults ( 2.2 ) Oral: Start at 10 mg or 15 mg once daily Bipolar I Disorder (manic or mixed episodes) in adolescents ( 2.2 ) Oral: Start at 2.5 mg to 5 mg once daily; Target: 10 mg/day Bipolar I Disorder (manic or mixed episodes) with lithium or valproate in adults ( 2.
Black Box Warning
WARNING: 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. Analyses of seventeen placebo-controlled trials (modal duration of 10 weeks), largely in patients taking atypical antipsychotic drugs, revealed a risk of death in drug-treated patients of between 1.6 to 1.7 times the risk of death in placebo-treated patients. Over the course of a typical 10-week controlled trial, the rate of death in drug-treated patients was about 4.
Contraindications
- 4 CONTRAINDICATIONS None with olanzapine monotherapy. When using olanzapine and fluoxetine in combination, also refer to the Contraindications section of the package insert for Symbyax. For specific information about the contraindications of lithium or valproate, refer to the Contraindications section of the package inserts for these other products. None with olanzapine monotherapy.( 4 ) When using olanzapine and fluoxetine in combination, also refer to the Contraindications section of the package insert for Symbyax ® .
Side Effects
- 6 ADVERSE REACTIONS When using olanzapine and fluoxetine in combination, also refer to the Adverse Reactions section of the package insert for Symbyax. Most common adverse reactions (≥5% and at least twice that for placebo) associated with: Oral Olanzapine Monotherapy: Schizophrenia (Adults) – postural hypotension, constipation, weight gain, dizziness, personality disorder, akathisia ( 6.1 ) Schizophrenia (Adolescents) – sedation, weight increased, headache, increased appetite, dizziness, abdominal pain, pain in extremity, fatigue, dry mouth ( 6.
Interactions
- 7 DRUG INTERACTIONS The risks of using olanzapine in combination with other drugs have not been extensively evaluated in systematic studies. Diazepam: May potentiate orthostatic hypotension. ( 7.1 , 7.2 ) Alcohol: May potentiate orthostatic hypotension. ( 7.1 ) Carbamazepine: Increased clearance of olanzapine. ( 7.1 ) Fluvoxamine: May increase olanzapine levels. ( 7.1 ) Olanzapine and Fluoxetine in Combination: Also refer to the Drug Interactions section of the package insert for Symbyax. ( 7.