Is Olanzapine (Zyprexa) effective for treating schizophrenia?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: February 16, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Guidelines

Olanzapine is an effective atypical antipsychotic medication for the treatment of schizophrenia.

Key Points

  • The recommended initial dose of olanzapine is 5-10mg per day, titrated to a target dose of 10-20mg per day 1.
  • Clinical trials have demonstrated its efficacy in reducing symptoms of psychosis, such as hallucinations and delusions, with significant improvements observed within 6-8 weeks of treatment 1.
  • Long-term treatment with olanzapine, typically lasting 6-12 months or longer, has also been shown to prevent relapse and improve functional outcomes in patients with schizophrenia 1.
  • Atypical antipsychotics, including olanzapine, have a lower risk of extrapyramidal symptoms compared to traditional neuroleptics, but may have other serious side effects, such as weight gain 1.
  • Initial target doses for most patients are risperidone 2 mg/day or olanzapine 7.5–10.0 mg/day, with dose increases only at widely spaced intervals if the response has been inadequate 1.
  • Treatment should commence prior to the development of a crisis, such as self-harm, violence or aggression, and may be an appropriate alternative to in-patient admission 1.
  • Olanzapine has been shown to be effective in reducing positive symptoms, but may not markedly improve negative symptoms or cognitive defects 1.
  • Some patients with schizophrenia may require long-term, even lifetime, medication to control their symptoms and do not achieve complete recovery 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).

Olanzapine (Zyprexa) is effective for treating schizophrenia in adults and adolescents (ages 13-17), as established by clinical trials 2.

  • Key points:
    • Efficacy was established in three clinical trials in adults with schizophrenia.
    • Efficacy was established in one 6-week trial in adolescents with schizophrenia.

From the Research

Efficacy of Olanzapine in Treating Schizophrenia

  • Olanzapine has been shown to be effective in treating schizophrenia, with studies demonstrating its superiority to placebo in improving clinical response 3, 4.
  • Compared to typical antipsychotic drugs, olanzapine appears to be as effective, but with fewer extrapyramidal adverse effects 3, 4.
  • Olanzapine has also been shown to be effective in treating negative symptoms of schizophrenia, with some studies suggesting it may be more effective than haloperidol in this regard 5, 6.

Comparison to Other Atypical Antipsychotics

  • Olanzapine has been compared to other atypical antipsychotics, such as risperidone, with mixed results 6.
  • Some studies have suggested that olanzapine may be more effective than risperidone in treating negative and depressive symptoms, but not in overall psychopathology symptoms 6.
  • Olanzapine has also been shown to have a more favorable side effect profile compared to risperidone, with fewer extrapyramidal symptoms and no risk of agranulocytosis 6.

Safety and Tolerability

  • Olanzapine has been associated with several adverse effects, including weight gain, dry mouth, and increased appetite 3, 4, 6.
  • However, it has also been shown to have a lower risk of extrapyramidal symptoms compared to typical antipsychotic drugs 3, 4, 5.
  • The long-acting parenteral formulation of olanzapine has been shown to be safe and effective, with no new adverse events noted beyond those seen with oral olanzapine 7.

Clinical Use

  • Olanzapine is widely used in the treatment of schizophrenia and bipolar disorder, and has been shown to be effective in both acute and maintenance treatment 6, 7.
  • The choice of olanzapine as a first-line treatment option is supported by its therapeutic superiority and reduced risk of adverse events compared to other antipsychotics 6.

References

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.