OLANZAPINE oral

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 extrapyramidal 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 treatment in the 3^rd trimester. If treatment starts during pregnancy, preferably use haloperidol.
• Breast-feeding: if absolutely necessary, do not exceed 10 mg daily. 

Storage