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olanzapine

AntipsychoticLAI available

Brands: ZYPREXA

Last reviewed 2025-12-28

Reviewed by PsychMed Editorial Team.

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Quick answers

  • What is olanzapine?

    Olanzapine (brand Zyprexa) is a second-generation antipsychotic (SGA) with broad efficacy across schizophrenia and bipolar disorder but notable metabolic adverse effects.

  • What is ZYPREXA?

    ZYPREXA is a brand name for olanzapine.

  • What is ZYPREXA (olanzapine) used for?

    Label indications include: Schizophrenia; acute treatment of manic or mixed episodes (bipolar I) and maintenance; in combination with fluoxetine for bipolar depression.

  • What drug class is ZYPREXA (olanzapine)?

    Antipsychotic.

  • What is the mechanism of action of ZYPREXA (olanzapine)?

    Antagonist at serotonin 5‑HT2A and dopamine D2 receptors; strong H1 and muscarinic activity.

  • What strengths does ZYPREXA (olanzapine) come in?

    Oral tablets: 2.5–20 mg; orally disintegrating tablets (Zyprexa Zydis): 5–20 mg.

  • Is ZYPREXA (olanzapine) a controlled substance?

    No — it is not scheduled as a controlled substance under U.S. federal law.

  • What is ZYPREXA (olanzapine) dosing for schizophrenia?

    Schizophrenia (adults): initiate 5–10 mg once daily; titrate by 5 mg increments at ≥24-hour intervals to 10–20 mg/day (max 20 mg).

Snapshot

  • Class: Antipsychotic
  • Common US brands: ZYPREXA
  • Long-acting injectable formulation available.
  • Therapeutic drug monitoring not routinely recommended.
  • Last reviewed: 2025-12-28

Label indications

Schizophrenia; acute treatment of manic or mixed episodes (bipolar I) and maintenance; in combination with fluoxetine for bipolar depression.

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Clinical Highlights

Olanzapine (brand Zyprexa) is a second-generation antipsychotic (SGA) with broad efficacy across schizophrenia and bipolar disorder but notable metabolic adverse effects. This profile focuses on adult and adolescent schizophrenia, bipolar I mania/mixed states, and bipolar depression in combination (Symbyax), while noting depot (Relprevv) REMS requirements.

Read more
  • The compare tool and olanzapine evidence feed can help weigh metabolic risk, EPS, and sedation trade-offs with alternative SGAs.
  • Despite metabolic liabilities, olanzapine is favored for severe agitation, treatment-resistant schizophrenia, and sedation needs; weight gain, dyslipidemia, and glucose dysregulation make structured metabolic monitoring standard to reduce metabolic syndrome risk.
  • Schizophrenia (adults) (FDA 1996)
  • Schizophrenia (adolescents 13–17) (FDA 2000)
  • Bipolar I mania/mixed (adults) (FDA 2000)

Dosing & Formulations

Oral tablets: 2.5–20 mg; orally disintegrating tablets (Zyprexa Zydis): 5–20 mg. Intramuscular injection: 10 mg vials for acute agitation.

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  • Long-acting depot (Zyprexa Relprevv): 210 mg, 300 mg, 405 mg every 2–4 weeks; consult the LAI navigator for observation requirements.
  • Schizophrenia (adults): initiate 5–10 mg once daily; titrate by 5 mg increments at ≥24-hour intervals to 10–20 mg/day (max 20 mg).
  • Schizophrenia (adolescents): start 2.5–5 mg/day; titrate to 5–20 mg/day.
  • Bipolar I mania/mixed: 10–15 mg once daily; IM 10 mg for agitation up to 3 doses/24 h.

Monitoring & Risks

Boxed warning: Increased mortality in elderly patients with dementia-related psychosis (class warning). Weight gain: ≥7% gain in 30–50% of patients within 6 months; mean 4–7 kg.

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  • Sedation/somnolence: Up to 40% experience significant sedation.
  • Dry mouth/constipation: Anticholinergic effects present in ~10–20%.
  • Metabolic changes: Hyperlipidemia and hyperglycemia common; structured metabolic labs are commonly used.
  • Increased appetite: Around 30% report appetite increase.

Drug Interactions

CYP1A2 inhibitors (fluvoxamine, ciprofloxacin) elevate levels—reduce dose adjustments and monitoring for sedation/metabolic issues are common. CYP1A2 inducers (smoking, carbamazepine, omeprazole) lower exposure—dose increases are sometimes needed.

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  • CYP2D6 inhibitors (fluoxetine, paroxetine) modestly increase levels; tolerability monitoring is common.
  • Additive CNS depression with alcohol, benzodiazepines, opioids.
  • Antagonizes dopamine agonists (levodopa); generally avoided in Parkinson’s disease when feasible.

Practice Notes

Lifestyle interventions (diet, exercise) are commonly started early to mitigate weight gain. Early follow-up after initiation or dose changes is common to address appetite and sleepiness; connecting patients to nutrition and activity supports early can limit downstream weight gain.

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  • Smoking cessation increases plasma levels—dosing is often reassessed if tobacco use changes.
  • Prophylactic bowel regimens are sometimes considered in patients prone to constipation.
  • Depot therapy requires REMS participation due to PDSS risk; use the LAI navigator to plan observation logistics.
  • Baseline and periodic metabolic labs (weight, fasting lipids/glucose, A1c) are standard.
  • Mania/hypomania monitoring can be coordinated via the bipolar disorder hub when olanzapine augments mood stabilisers.

Long-acting injectable (LAI) options

References

  1. ZYPREXA prescribing information — DailyMed (2025)
  2. ZYPREXA RELPREVV prescribing information
  3. Allison1999 Antipsychotic Weight Gain
  4. Metabolic AND Endocrine Adverse Effects OF Second Generation Antipsychotics: A Systematic Review — CNS Drugs (2011)
  5. Effectiveness of antipsychotic drugs in patients with chronic schizophrenia — The New England Journal of Medicine (2005)
Olanzapine (ZYPREXA) — Summary — PsychMed