What are the indications and dosages for Olanzapine (olanzapine)?

Olanzapine Indications and Dosages

Olanzapine is indicated for schizophrenia, bipolar disorder (both manic/mixed episodes and depression), and as adjunctive therapy for treatment-resistant depression, with specific dosing regimens for each indication. 1

Indications for Olanzapine

Schizophrenia

• Adult dosing: 5-20 mg once daily 1
  • Initial dose: 5-10 mg once daily
  • Maintenance: Lowest effective dose (typically 10-15 mg/day)
  • Maximum: 20 mg/day (safety of higher doses not well established)
• Adolescent dosing (13-17 years): 2.5-20 mg once daily 1
  • Initial dose: 2.5-5 mg once daily
  • Target dose: 10 mg/day
  • Maximum: 20 mg/day

Bipolar I Disorder

• Acute manic/mixed episodes:
  • Adults: 10-15 mg once daily; range 5-20 mg/day 1, 2
  • Adolescents (13-17 years): Initial 2.5-5 mg once daily; target 10 mg/day 1
• Maintenance therapy for bipolar I disorder:
  • Continue at lowest dose needed to maintain remission 1
  • Superior to placebo in preventing both manic and depressive relapses 2, 3

Bipolar Depression

• In combination with fluoxetine (Symbyax or individual components):
  • Adults: Olanzapine 5-12.5 mg with fluoxetine 20-50 mg once daily 1
  • Adolescents (10-17 years): Olanzapine 2.5-12 mg with fluoxetine 20-50 mg once daily 1

Treatment-Resistant Depression

• In combination with fluoxetine: Olanzapine 5-20 mg with fluoxetine 20-50 mg once daily 1

Acute Agitation

• Intramuscular injection for acute agitation in schizophrenia or bipolar mania:
  • Standard dose: 10 mg IM 1
  • Lower doses (5-7.5 mg) for elderly or medically compromised patients 1
  • Maximum: 3 doses in 24 hours, at least 2 hours apart 1

Special Populations and Considerations

Elderly Patients

• Lower starting doses (2.5-5 mg/day) recommended 1
• Higher risk of adverse effects, particularly orthostatic hypotension 1
• Use with caution due to increased mortality in elderly patients with dementia-related psychosis (boxed warning) 4, 5

Formulations

• Oral tablets
• Orally disintegrating tablets (ZYDIS): Place on tongue, dissolves rapidly in saliva 1
• Intramuscular injection: For acute agitation, reconstituted with sterile water 1

Efficacy Considerations

• Effective for both positive and negative symptoms of schizophrenia 6, 7
• Comparable or superior efficacy to conventional antipsychotics like haloperidol 6, 7
• Reduces relapse risk and rehospitalization rates compared to conventional antipsychotics 6
• Particularly effective for depressive symptoms in schizophrenia and bipolar disorder 6, 2

Safety and Monitoring

• Common adverse effects:

  • Weight gain (significant concern)
  • Somnolence and sedation
  • Anticholinergic effects (dry mouth, constipation)
  • Transient liver enzyme elevations 6, 8

• Metabolic concerns:

  • Monitor for development of metabolic syndrome
  • Regular monitoring of weight, blood glucose, and lipid profiles recommended 2

• Suicide risk monitoring:

  • Close monitoring during first 1-2 weeks of therapy initiation 5
  • Highest risk period for suicide attempts is during first 1-2 months of treatment 5
  • Document baseline mental status and suicidal ideation before starting treatment 5

Drug Interactions and Contraindications

• Avoid combining olanzapine in syringe with diazepam, lorazepam, or haloperidol injections 1
• Use caution when combining with other CNS depressants
• Avoid excessive dopamine blockade when using concurrently with metoclopramide, phenothiazines, or haloperidol 4

Clinical Pearls

• Olanzapine can be used as part of a 4-drug antiemetic regimen for chemotherapy-induced nausea and vomiting 4
• Lower extrapyramidal symptoms compared to typical antipsychotics and some atypical antipsychotics 6
• Does not cause agranulocytosis (unlike clozapine) or significant hyperprolactinemia (unlike risperidone) 6
• Consider 5 mg dose in elderly or oversedated patients instead of standard 10 mg dose 4

Olanzapine offers significant advantages in efficacy and tolerability compared to conventional antipsychotics, making it a valuable first-line option for schizophrenia and bipolar disorder, though metabolic side effects require careful monitoring and management.