Olanzapine
ZYPREXA
Pronunciation: oe-LAN-za-peen (zye-PREX-a)
“Owl lands upon (cra)Zy pretzel”
Spooky mascot → antipsychotic
Crown → antihistamine
Pretzel → weight gain
What it isBroad D2, 5-HT2A, histamine, muscarinic, and adrenergic antagonist; schizophrenia and bipolar disorder.
Why this oneAmong the most effective antipsychotics, it also has an intramuscular option for acute agitation.
What limits itWeight, lipids, and glucose can worsen dramatically; smoking cessation raises exposure through loss of CYP1A2 induction.
Pearls
- Samidorphan combination blunts weight gain.
- Bipolar depression only as olanzapine–fluoxetine combination.
- Rare DRESS.
Olanzapine prescription history
Animated chart of estimated U.S. prescriptions per year, Antipsychotics (1954–2026). Olanzapine enters in 1996 (estimated).
FDA-approved for
- schizophrenia (1996)
- bipolar disorder (2000)
Off-label
- chemo nausea
- anorexia nervosa
Classes and tags
Clinical profile
Legacy pregnancy categoryC
Defining liabilityWeight gain, hyperglycemia and dyslipidemia; sedation, orthostatic hypotension and falls; anticholinergic effects; DRESS; increased mortality in elderly patients with dementia-related psychosis.
FDA label
Read the full label on DailyMed ↗
| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| Schizophrenia | Adult | 5–10 mg QD | 10 mg/day | 20 mg/day |
| Schizophrenia | Adolescent | 2.5–5 mg QD | 10 mg/day | 20 mg/day |
| Bipolar I, manic/mixed (monotherapy) | Adult | 10 or 15 mg QD | 5–20 mg/day | 20 mg/day |
| Bipolar I, manic/mixed (monotherapy) | Adolescent | 2.5–5 mg QD | 10 mg/day | 20 mg/day |
| Bipolar I, manic/mixed (with lithium or valproate) | Adult | 10 mg QD | 5–20 mg/day | 20 mg/day |
| Depressive episodes in Bipolar I (with fluoxetine) | Adult | 5 mg olanzapine + 20 mg fluoxetine QD | ||
| Depressive episodes in Bipolar I (with fluoxetine) | Child/adolescent | 2.5 mg olanzapine + 20 mg fluoxetine QD | ||
| Treatment-resistant depression (with fluoxetine) | Adult | 5 mg olanzapine + 20 mg fluoxetine QD |
Renal Undefined
Hepatic Undefined
Instructions
- May be given with or without meals
- Use lower starting dose in debilitated or pharmacodynamically sensitive patients, those prone to hypotension, or with slowed metabolism
- For combination with fluoxetine, adjust each component individually
Available strengths
- tab 2.5, 5, 7.5, 10, 15, 20 mg
- ODT 5, 10, 15, 20 mg
- inj 10 mg
Cautions
- Elderly with dementia-related psychosis: increased death and cerebrovascular events
- Suicide risk in schizophrenia/bipolar
- Neuroleptic malignant syndrome
- DRESS
- Metabolic changes: hyperglycemia/diabetes (incl. ketoacidosis), dyslipidemia, weight gain
- Orthostatic hypotension, seizures, tardive dyskinesia
Adverse reactions
- Somnolence/sedation
- Weight gain, increased appetite
- Dizziness, postural hypotension
- Constipation, dry mouth
- Akathisia, tremor
- Asthenia/fatigue
Pregnancy Third-trimester exposure risks extrapyramidal/withdrawal symptoms in neonates; no established drug-associated major-malformation risk. Pregnancy registry available.
Lactation Present in human milk; monitor infant for sedation, irritability, poor feeding, extrapyramidal symptoms.
Cost
| Strength | #/mo | generic $/mo | CostPlus | |
|---|---|---|---|---|
| 2.5 mg | tab | 30 qd | $2.43 | offered |
| 5 mg | tab | 30 qd | $2.61 | offered |
| 7.5 mg | tab | 30 qd | $2.83 | offered |
| 10 mg | tab | 30 qd | $3.27 | offered |
| 15 mg | tab | 30 qd | $4.04 | offered |
| 20 mg | tab | 30 qd | $4.40 | offered |
Other forms: Olanzapine IM (ZYPREXA INTRAMUSCULAR)
Available combined with: Samidorphan (in LYBALVI) · olanzapine / fluoxetine · olanzapine / samidorphan
Generic entry2011
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Memory aids: interaction avatars
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Self-check
- Why does stopping smoking raise olanzapine exposure?
Loss of CYP1A2 induction. - What metabolic measures can olanzapine markedly worsen?
Weight, lipids and glucose.