What is the efficacy of Olanzapine (Zyprexa) for treating schizophrenia and bipolar disorder?

From the Guidelines

Zyprexa (olanzapine) is a recommended medication for treating schizophrenia and bipolar disorder, with a typical starting dose of 5-10 mg once daily for schizophrenia and 10-15 mg daily for acute mania in bipolar disorder, as supported by the American Psychiatric Association practice guideline for the treatment of patients with schizophrenia 1.

Key Considerations

• The medication works by blocking multiple neurotransmitter receptors, particularly dopamine D2 and serotonin 5-HT2A receptors, which helps control psychotic symptoms, mood swings, and agitation.
• Common side effects include weight gain, increased blood sugar, drowsiness, and dry mouth, and regular monitoring of weight, blood glucose, and lipid levels is necessary.
• Zyprexa should be taken as prescribed, typically once daily, and stopping the medication abruptly can cause withdrawal symptoms.
• It may take 1-2 weeks to notice initial improvements, with full benefits developing over 4-6 weeks.
• Zyprexa can be taken with or without food, and patients should avoid alcohol while on this medication.

Dosage and Administration

• For schizophrenia, the dose can be increased to 10-20 mg daily based on response, as recommended by the American Psychiatric Association practice guideline for the treatment of patients with schizophrenia 1.
• For bipolar disorder, maintenance doses of 5-20 mg daily are typically used, as supported by the practice parameter for the assessment and treatment of children and adolescents with bipolar disorder 1.

Important Considerations

• Patients with schizophrenia should have a documented, comprehensive, and person-centered treatment plan that includes evidence-based nonpharmacological and pharmacological treatments, as recommended by the American Psychiatric Association practice guideline for the treatment of patients with schizophrenia 1.
• Patients with treatment-resistant schizophrenia may benefit from treatment with clozapine, as suggested by the American Psychiatric Association practice guideline for the treatment of patients with schizophrenia 1.
• Regular monitoring of patients with schizophrenia is necessary to assess the effectiveness and side effects of treatment, as recommended by the American Psychiatric Association practice guideline for the treatment of patients with schizophrenia 1.

From the FDA Drug Label

ZYPREXA® (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). Acute treatment of manic or mixed episodes associated with bipolar I disorder and maintenance treatment of bipolar I disorder. (1.2) Adults: Efficacy was established in three clinical trials in patients with manic or mixed episodes of bipolar I disorder: two 3- to 4-week trials and one maintenance trial. (14.2) Adolescents (ages 13-17): Efficacy was established in one 3-week trial in patients with manic or mixed episodes associated with bipolar I disorder (14.2).

Zyprexa is indicated for the treatment of schizophrenia and bipolar I disorder. The efficacy of Zyprexa for the treatment of schizophrenia was established in three clinical trials in adults and one clinical trial in adolescents. The efficacy of Zyprexa for the treatment of bipolar I disorder was established in three clinical trials in adults and one clinical trial in adolescents.

• Schizophrenia: Zyprexa is indicated for the treatment of schizophrenia in adults and adolescents (ages 13-17) 2.
• Bipolar I Disorder: Zyprexa is indicated for the acute treatment of manic or mixed episodes associated with bipolar I disorder and maintenance treatment of bipolar I disorder in adults and adolescents (ages 13-17) 2.

From the Research

Zyprexa (Olanzapine) for Schizophrenia and Bipolar Disorder

• Zyprexa (olanzapine) is a second-generation (atypical) antipsychotic agent that has proven efficacy against the positive and negative symptoms of schizophrenia 3.
• In patients with schizophrenia, olanzapine has been shown to be significantly superior to haloperidol in overall improvements in psychopathology rating scales and in the treatment of depressive and negative symptoms 3.
• Olanzapine has also been found to be effective in the treatment of bipolar I disorder, with significant antimanic efficacy compared to placebo 4.
• In the treatment of acute manic or mixed episodes of bipolar I disorder, olanzapine has been shown to be at least as effective as haloperidol and valproate semisodium 4.

Comparison with Other Antipsychotics

• Olanzapine has been compared to risperidone in several studies, with mixed results 3, 5.
• In one study, olanzapine was found to be significantly more effective than risperidone in the treatment of negative and depressive symptoms, but not in overall psychopathology symptoms 3.
• Another study found that once-daily dosing of olanzapine was associated with a lower mean daily dose and fewer side effects compared to twice-daily dosing 5.

Safety and Tolerability

• Olanzapine is generally well tolerated, with common adverse events including somnolence, dry mouth, dizziness, and bodyweight gain 3, 4.
• Olanzapine has been found to have a lower risk of extrapyramidal symptoms compared to haloperidol and risperidone 3, 6.
• Asenapine, another second-generation antipsychotic, has been found to have a favorable weight and metabolic profile compared to olanzapine 6.