Olanzapine

Generic Name: Olanzapine

Brand Names:

Availability: Available with Prescription

Drug Class: Atypical Antipsychotics

Therapeutic action

  • Atypical antipsychotic

Indications

  • Acute and chronic psychosis and acute manic episode, in the event of intolerance or treatment failure with other antipsychotics (preferably use haloperidol for these indications)

Forms and strengths

  • 2.5 mg, 5 mg and 10 mg tablets

Dosage

  • Adult: 10 mg once daily. Increase up to 15 mg daily if necessary (max. 20 mg daily). 
  • Reduce the dose by half in older patients (max. 10 mg daily).

Duration

  • Acute psychosis: at least 3 months 
  • Chronic psychosis: at least one year
  • Manic episode: 8 weeks after remission of symptoms

Discontinue treatment gradually (over 4 weeks). If signs of relapse occur, increase the dose then decrease it more gradually.

Contra-indications, adverse effects, precautions

  • Do not administer to patients with cardiac disorders (heart failure, recent myocardial infarction, conduction disorders, bradycardia, etc.), dementia (e.g. Alzheimer's disease), Parkinson's disease,history of neuroleptic malignant syndrome and closed-angle glaucoma.
  • Administer with caution and carefully monitor use in older patients and patients with hypokalaemia, hypotension, prostate disorders, renal or hepatic impairment, history of seizures.
  • May cause: orthostatic hypotension, drowsiness (caution when driving/operating machinery), extrapyramidal symptoms, hyperprolactinaemia, weight gain, hyperlipidaemia, hyperglycaemia, anticholinergic effects (constipation, dry mouth), headache, insomnia, dizziness, sexual dysfunction; neuroleptic malignant syndrome(unexplained hyperthermia with neuromuscular disorders), rare but requiring immediate treatment discontinuation.
  • In case of extrapyramidal symptoms, try reducing the dose of olanzapine or, if the extra pyramidal symptoms are severe, add biperiden or trihexyphenidyl.
  • Avoid or monitor combination with:
    • central nervous system depressants (opioid analgesics, sedatives, H1 antihistamines, etc.); 
    • ciprofloxacin (increased plasma concentrations of olanzapine);
    • carbamazepine, rifampicin, phenobarbital, phenytoin, ritonavir(decreased plasma concentrations of olanzapine);
    • antihypertensive drugs (risk of hypotension); drugs that prolong the QT interval (amiodarone, chloroquine, erythromycin, fluconazole, mefloquine, pentamidine, quinine, etc.).
  • Avoid alcohol during treatment(increased risk of adverse effects).
  • Pregnancy: re-evaluate whether the treatment is still necessary; if it is continued, use the lowest effective dose. Observe the neonate the first few days (risk of agitation, tremors,hypertonia/hypotonia, respiratory difficulties, sleeping disorders, etc.) if the mother was under treatmentin the 3rd trimester. If treatment starts during pregnancy, preferably use haloperidol.
  • Breast-feeding: if absolutely necessary,do not exceed 10 mg daily.

Storage

– Below 25 °C