What is the dose of Olanzapine (Zyprexa)?

From the Guidelines

The recommended initial dosage of Zyprexa (olanzapine) is 2.5 mg per day at bedtime, with a maximum dosage of 10 mg per day, usually twice daily in divided doses. This dosage is generally well tolerated, as noted in the guidelines for managing Alzheimer's disease 1. The treatment of behavior and mood disorders with atypical antipsychotic agents like olanzapine is recommended for control of problematic delusions, hallucinations, severe psychomotor agitation, and combativeness.

Key Considerations

• The initial dosage of 2.5 mg per day at bedtime is recommended, with the option to increase to a maximum of 10 mg per day if necessary.
• Olanzapine is generally well tolerated, with a diminished risk of developing extrapyramidal symptoms and tardive dyskinesia compared to typical antipsychotic agents 1.
• Regular monitoring of side effects, such as weight gain, increased appetite, drowsiness, and metabolic changes, is essential during treatment.

Comparison with Other Agents

• Other atypical antipsychotic agents, such as risperidone and quetiapine, have different recommended dosages and side effect profiles 1.
• Typical antipsychotic agents, such as haloperidol and fluphenazine, are associated with significant side effects and should be avoided if possible 1.

Clinical Implications

• The dosage of Zyprexa should be adjusted gradually, typically at intervals of 5-7 days, to minimize the risk of side effects and ensure optimal therapeutic effect.
• Abrupt discontinuation of Zyprexa should be avoided, and the medication should be tapered gradually to prevent withdrawal symptoms or relapse of the underlying condition.

From the FDA Drug Label

2 Bipolar I Disorder (Manic or Mixed Episodes) Adults Dose Selection for Monotherapy — Oral olanzapine should be administered on a once-a-day schedule without regard to meals, generally beginning with 10 or 15 mg. Dosage adjustments, if indicated, should generally occur at intervals of not less than 24 hours, reflecting the procedures in the placebo-controlled trials When dosage adjustments are necessary, dose increments/decrements of 5 mg QD are recommended. Short-term (3-4 weeks) antimanic efficacy was demonstrated in a dose range of 5 mg to 20 mg/day in clinical trials.

The recommended dose for ZYPREXA is:

• Initial dose: 10 or 15 mg once daily
• Dose adjustment: increments/decrements of 5 mg QD
• Effective dose range: 5 mg to 20 mg/day 2

From the Research

ZYPREXA Dose Overview

• The typical dose of ZYPREXA (olanzapine) can vary depending on the patient's condition and response to treatment 3, 4.
• Studies have shown that doses above 20 mg/day may be more efficacious for some patients, particularly those with treatment-resistant schizophrenia or bipolar disorder 3.
• However, higher doses are also associated with an increased risk of weight gain and elevated prolactin levels 3, 5.

Dosing Regimens

• Research has compared the effectiveness of once-daily versus twice-daily dosing regimens for olanzapine and risperidone in patients with schizophrenia 6.
• The study found no significant differences in discontinuation rates and time to discontinuation between the two dosing groups, but once-daily dosing was associated with lower mean daily doses and fewer side effects 6.
• Another study examined the factors associated with prescribing olanzapine, quetiapine, and risperidone in patients with bipolar and related affective disorders, and found that clinical factors such as mania, psychosis, and inpatient treatment were associated with initiation of these medications 7.

Efficacy and Safety

• Olanzapine has been shown to be effective in treating overall psychopathology in acute schizophrenia, with superior efficacy for negative and depressive symptoms compared to haloperidol 4.
• However, olanzapine is also associated with dose-related weight gain and asymptomatic mild transaminase elevations 4, 5.
• The efficacy and tolerability of olanzapine, risperidone, and clozapine have been compared in patients with bipolar disorder, and found to be similar, although olanzapine was associated with significant weight gain 5.