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Second-Generation Antipsychotic Pregnancy: Avoid in pregnancy unless clearly necessary; neonatal extrapyramidal symptoms reported

Olanzapine

Brand names: Zyprexa

Adult dose

Dose: 5-20 mg once daily (schizophrenia); 5-10 mg (bipolar mania)
Route: Oral / IM
Frequency: Once daily
Max: 20 mg/day
In elderly: start at 2.5-5 mg; use lowest effective dose for shortest duration

Paediatric dose

Dose: Seek specialist opinion N/A/kg
Route: Oral
Frequency: Seek specialist opinion
Max: Seek specialist opinion
Seek specialist opinion

Dose adjustments

Renal

No dose adjustment required

Hepatic

Use with caution; consider lower starting dose

Paediatric weight-based calculator

Seek specialist opinion

Clinical pearls

  • MHRA 2004 and 2009: Antipsychotics (including olanzapine) approximately double the risk of stroke and increase mortality in elderly patients with dementia — use only when non-pharmacological measures have failed, for the shortest time at the lowest dose
  • Beers Criteria 2023 and STOPP v3: Antipsychotics in elderly are potentially inappropriate unless for schizophrenia, bipolar disorder, or severe treatment-resistant agitation
  • Metabolic monitoring essential — olanzapine has the highest metabolic risk among second-generation antipsychotics
  • NOT licensed for behavioural symptoms of dementia (unlike risperidone, which has a 6-week licence) — use is off-label
  • Sedation and falls risk: avoid in ambulatory elderly patients where possible

Contraindications

  • Narrow-angle glaucoma

Side effects

  • Sedation (prominent)
  • Weight gain (significant)
  • Metabolic syndrome (diabetes, dyslipidaemia)
  • Postural hypotension
  • Anticholinergic effects
  • QT prolongation
  • Extrapyramidal symptoms (less than haloperidol)
  • Stroke (increased risk in elderly with dementia)

Interactions

  • CNS depressants (additive sedation)
  • QT-prolonging drugs (additive risk)
  • Anticholinergics (additive)
  • Fluvoxamine / ciprofloxacin (CYP1A2 inhibitors — increase olanzapine levels)
  • Carbamazepine (reduces levels)

Monitoring

  • Weight and BMI (baseline and 3-monthly)
  • Fasting glucose and HbA1c
  • Lipid profile
  • Blood pressure (postural)
  • ECG (QTc)
  • Neurological symptoms (EPSE)
  • Cognitive function

Reference: BNFc; BNF 90; MHRA Drug Safety Update 2004 and 2009 (antipsychotics in dementia); AGS Beers Criteria 2023; STOPP/START v3. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

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