Olanzapine Dosing Guidelines for Schizophrenia and Bipolar Disorder
For patients with schizophrenia or bipolar disorder, olanzapine should be initiated at 5-10 mg once daily for adults and 2.5-5 mg once daily for adolescents, with dose adjustments based on clinical response and tolerability.
Adult Dosing Recommendations
Schizophrenia
- Initial dose: 5-10 mg orally once daily 1
- Target dose: 10 mg/day within several days 1
- Maximum FDA-approved dose: 20 mg/day 1, 2
Bipolar I Disorder (Manic or Mixed Episodes)
- Initial dose: 10-15 mg orally once daily 1
- When used as adjunct to lithium or valproate: Start at 10 mg once daily 1
- Maintenance treatment: Dose that has shown response in acute phase 1, 3
Adolescent Dosing Recommendations (Ages 13-17)
Schizophrenia
- Initial dose: 2.5-5 mg orally once daily 1, 4
- Target dose: 10 mg/day 1
- Lower starting doses recommended due to increased risk of weight gain and metabolic effects compared to adults 1, 4
Bipolar I Disorder (Manic or Mixed Episodes)
- Initial dose: 2.5-5 mg orally once daily 1, 4
- Target dose: 10 mg/day 1
- Careful monitoring required for metabolic effects 4
Special Populations
- Elderly or Debilitated Patients: Lower starting dose (2.5-5 mg) recommended 5, 1
- Hepatic Impairment: Start with 2.5 mg daily 5, 1
- Patients with potential for slowed metabolism: Lower starting dose recommended 1
Administration Routes and Formulations
- Oral tablets: 2.5,7.5,10,15,20 mg 1
- Orally disintegrating tablets (Zydis): 5,10,15,20 mg 1
- Intramuscular injection: 10 mg (5-7.5 mg when clinically warranted) for acute agitation 1
- Olanzapine may be given without regard to meals 1
Monitoring and Safety Considerations
- Metabolic monitoring: Weight gain, hyperglycemia, and dyslipidemia are common side effects requiring regular monitoring 1, 4
- Common adverse effects: Somnolence, weight gain, increased appetite, dry mouth, and dizziness 6, 4
- Extrapyramidal symptoms: Less common than with typical antipsychotics but still occur in approximately 10% of patients 6, 4
- Drug interactions: Use caution when combining with benzodiazepines due to risk of oversedation and respiratory depression 7, 5
- Warning: Fatalities have been reported with concurrent use of benzodiazepines and high-dose olanzapine 7, 5
Important Clinical Considerations
- Olanzapine has demonstrated efficacy against both positive and negative symptoms of schizophrenia 6
- In bipolar disorder, olanzapine is effective for acute manic or mixed episodes and maintenance treatment 1, 3
- Olanzapine may be more effective than some other antipsychotics for treating negative and depressive symptoms 6
- Although clinical practice sometimes involves doses higher than 20 mg/day, evidence supporting higher dosing is limited and must be balanced against increased risk of adverse effects 2
Caution
- Black Box Warning: Elderly patients with dementia-related psychosis treated with antipsychotics have increased risk of death. Olanzapine is not approved for treatment of dementia-related psychosis 1
- Adolescents have increased risk of weight gain and metabolic effects compared to adults, which may lead clinicians to consider other medications first 1, 4