From the Guidelines
The starting dose of olanzapine is 2.5-5 mg p.o. or s.c. stat, with a recommended starting dose of 2.5-5 mg p.o. or s.c. daily, usually at bedtime, as stated in the most recent and highest quality study 1.
Key Considerations
- The dose can be gradually increased based on clinical response and tolerability, typically in 2.5-5 mg increments at intervals of at least 24 hours.
- For elderly patients or those with hepatic impairment, a lower starting dose is recommended.
- Olanzapine can cause significant metabolic side effects, including weight gain, increased blood glucose, and elevated lipids, so regular monitoring of weight, blood glucose, and lipid profiles is necessary.
Comparison with Other Studies
- A study from 2002 1 recommends an initial dosage of 2.5 mg per day at bedtime, with a maximum of 10 mg per day, usually twice daily in divided doses.
- A study from 2005 1 suggests examples of appropriate initial target doses for most patients are olanzapine 7.5–10.0 mg/day.
Prioritizing Recent and High-Quality Evidence
- The most recent and highest quality study 1 provides the most reliable guidance for the starting dose of olanzapine, prioritizing morbidity, mortality, and quality of life as the outcome.
- This study is more relevant to current clinical practice, and its recommendations should be followed in preference to older studies.
From the FDA Drug Label
2 DOSAGE AND ADMINISTRATION
- 1 Schizophrenia Adults Dose Selection — Oral olanzapine should be administered on a once-a-day schedule without regard to meals, generally beginning with 5 to 10 mg initially, with a target dose of 10 mg/day within several days ... Dosing in Special Populations — The recommended starting dose is 5 mg in patients who are debilitated, who have a predisposition to hypotensive reactions, who otherwise exhibit a combination of factors that may result in slower metabolism of olanzapine (e. g., nonsmoking female patients ≥65 years of age), or who may be more pharmacodynamically sensitive to olanzapine ... Adolescents Dose Selection — Oral olanzapine should be administered on a once-a-day schedule without regard to meals with a recommended starting dose of 2. 5 or 5 mg, with a target dose of 10 mg/day.
The starting dose of olanzapine is:
- 5 to 10 mg for adults with schizophrenia
- 2.5 or 5 mg for adolescents with schizophrenia
- 10 or 15 mg for adults with bipolar I disorder (manic or mixed episodes) 2
From the Research
Starting Dose of Olanzapine
The starting dose of olanzapine, an atypical antipsychotic, is discussed in several studies. Key points include:
- The recommended starting dosage is 5-10 mg orally once daily 3
- Olanzapine is generally administered at dosages of 5 to 20 mg/day for the treatment of schizophrenia and related psychoses 4
- In adolescents, the pharmacokinetics of oral olanzapine are similar to those in adults, and dose adjustments based on bodyweight or sex are not necessary 5
- When combined with aripiprazole, the olanzapine dosages may need to be adjusted, with recommended initial dosages ranging from 0.3 to 0.6 mg/kg/day depending on patient weight and administration frequency 6
Key Considerations
Some important considerations when determining the starting dose of olanzapine include:
- Patient weight and age
- Concomitant use of other medications, such as aripiprazole
- Individual patient response and tolerance to the medication
- The specific clinical indication being treated, such as schizophrenia or bipolar I disorder
Dosage Recommendations
Specific dosage recommendations for olanzapine include: