Intramuscular Acute agitation in patients with schizophrenia, Mania
Adult: Initially, 5-10 mg followed by 5-10 mg as required 2 hr later. Max: 20 mg/day (combined oral and parenteral dose). Patients could only receive up to 3 inj in any 24-hr period. May give inj for up to 3 days but should transfer to oral therapy as soon as possible.
Oral Acute manic episodes of bipolar disorder, Acute mixed episodes of bipolar disorder
Adult: Initially, 10 or 15 mg daily as monotherapy or 10 mg daily as part of combination therapy. Adjust dose in increments or decrements of 5 mg at intervals of not less than 24 hr to a dose of 5-20 mg daily.
Oral Schizophrenia
Adult: Initially, 10 mg daily as a single dose. Adjust dose according to response at intervals of not less than 24 hr w/in the range of 5-20 mg daily.
Renal Impairment
Initial: 5 mg daily.
Hepatic Impairment
Initial: 5 mg daily.
Administration
May be taken with or without food.
Contraindications
Patient w/ angle-closure glaucoma.
Special Precautions
Patient w/ cerebrovascular disease or conditions predisposing to hypotension, benign prostatic hyperplasia, paralytic ileus, DM, Parkinson's disease, history of blood dyscrasias, bone marrow depression, hypereosinophilic disorders, myeloproliferative disease, history of seizures or conditions that lower the seizure threshold. IM: Acute MI, unstable angina, severe hypotension or bradycardia, sick sinus syndrome, recent heart surgery. Elderly w/ dementia-related psychosis. Hepatic and renal impairment. Pregnancy and lactation.
Adverse Reactions
Somnolence, wt gain, hyperprolactinaemia, increased appetite, dizziness, fatigue, elevated plasma glucose, triglyceride and liver enzyme values, oedema, orthostatic hypotension, constipation, dry mouth; agranulocytosis, eosinophilia, leucopenia, neutropenia, thrombocytopenia; hypertriglyceridaemia, hypercholesterolaemia, bradycardia, arthralgia, sedation. Potentially Fatal: Neuroleptic malignant syndrome, pancreatitis, stroke, transient ischaemic attack, status epilepticus, exacerbation of pre-existing diabetes sometimes leading to ketoacidosis or coma.
This drug may cause somnolence and dizziness, if affected, avoid driving and operating machinery. Avoid cigarette smoking.
Monitoring Parameters
Monitor BP, pulse and resp rate for at least 4 hr after IM inj. Clinical monitoring for hyperglycaemia, plasma lipids and wt.
Overdosage
Symptoms: Tachycardia, agitation/aggressiveness, dysarthria, extrapyramidal symptoms, reduced level of consciousness ranging from sedation to coma. Management: Symptomatic and supportive treatment. Gastric lavage and admin of activated charcoal may be effective.
Drug Interactions
Increased olanzapine clearance w/ CYP1A2 inducers (e.g. carbamazepine, omeprazole). Inhibits metabolism w/ CYP1A2 inhibitors (e.g. fluvoxamine). May antagonise effects of levodopa and dopamine agonists. Reduced bioavailability w/ activated charcoal. Additive effect w/ centrally acting drugs or drugs known to increase QT interval.
Food Interaction
Alcohol may potentiate orthostatic hypotension.
Action
Description: Mechanism of Action: Olanzapine is an atypical antipsychotic w/ affinity for serotonin 5-HT2A/2C, dopamine D1-4, histamine H1 and adrenergic α1 receptors. Efficacy is thought to be mediated through combined antagonism of dopamine and serotonin type 2 receptor sites. Pharmacokinetics: Absorption: Well absorbed from the GI tract. Time to peak plasma concentration: Approx 5-8 hr (oral); approx 15-45 min (IM). Distribution: Distributed into breast milk. Plasma protein binding: Approx 93%. Metabolism: Extensively hepatic via direct glucuronidation and oxidation mediated by CYP1A2 isoenzyme and to a lesser extent, CYP2D6. Excretion: Via urine (approx 57%) mainly as metabolites and faeces (approx 30%). Plasma elimination half-life: Approx 30-38 hr.
Chemical Structure
Olanzapine Source: National Center for Biotechnology Information. PubChem Compound Summary for CID 135398745, Olanzapine. https://pubchem.ncbi.nlm.nih.gov/compound/Olanzapine. Accessed Jan. 31, 2024.
Storage
Store between 20-25°C. Protect from light, moisture and freezing.
Anon. Olanzapine. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 21/11/2014.Buckingham R (ed). Olanzapine. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 21/11/2014.Joint Formulary Committee. Olanzapine. British National Formulary [online]. London. BMJ Group and Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 21/11/2014.McEvoy GK, Snow EK, Miller J et al (eds). Olanzapine, Olanzapine Pamoate. AHFS Drug Information (AHFS DI) [online]. American Society of Health-System Pharmacists (ASHP). https://www.medicinescomplete.com. Accessed 21/11/2014.Olanzapine Injection Powder for Solution (Sandoz Inc). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed/. Accessed 21/11/2014.
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