Olanzapine

Olanzapine

ADMINISTRATION ROUTES:

  • PO, IM, NG

ALTERNATIVE NAMES:

  • Zyprexa

ICU INDICATIONS:

  1. agitation and delirium
  2. psychosis

PRESENTATION AND ADMINISTRATION:

  • IM:
    Zyprexa IM 10mg.
    Reconstitute with 2.1ml of sterile water for injection and administer by IM injection.
  • PO / NG:
    Tablets:
    Zyprexa 2.5mg tablets (white), Zyprexa 5mg tablets (white), Zyprexa 10mg tablets (white)
    Wafers:

    Zyprexa 5mg wafer (yellow), Zyprexa 10mg wafer (yellow)

    Note: for NG administration, dissolve wafers and give via NG tube

DOSAGE:

  • IM:
    Initially 5-10mg; may administer an additional dose of up to 10mg after 2 hours and a further dose of up to 10mg 4 hours after the second dose (max dose 30mg / 24 hours)
  • PO:
    5-20mg daily (can be administered in divided doses)

DOSAGE IN RENAL FAILURE AND RENAL REPLACEMENT THERAPY:

  • Dose in renal impairment [GFR (ml/min)]
    <10: initial dose of 5mg and titrate as necessary
    10-20: initial dose of 5mg and titrate as necessary
    >20-50: initial dose of 5mg and titrate as necessary
  • Dose in renal replacement therapy
    CAPD: initial dose of 5mg and titrate as necessary
    HD: initial dose of 5mg and titrate as necessary
    CVVHDF: initial dose of 5mg and titrate as necessary

DOSAGE IN PAEDIATRICS:

  • 0.1-0.2mg/kg daily oral; increase to 0.4mg/kg daily oral if required

CLINICAL PHARMACOLOGY:

  • Olanzapine is a selective monoaminergic antagonist. The mechanism of action of olanzapine is unknown; however, it has been proposed that this drug’s efficacy is mediated through a combination of dopamine and serotonin type 2 (5HT2) antagonism.

CONTRAINDICATIONS:

  1. sensitivity to olanzapine

WARNINGS

  • Increased risk of deaths in patients with dementia
    Elderly patients with dementia-related psychosis treated with atypical antipsychotic drugs are at an increased risk of death compared to placebo.
  • Hyperglycemia and Diabetes Mellitus
    Hyperglycemia, in some cases extreme and associated with ketoacidosis or hyperosmolar coma or death, has been reported in patients treated with atypical antipsychotics including olanzapine.
  • Neuroleptic Malignant Syndrome (NMS)
    A potentially fatal symptom complex sometimes referred to as Neuroleptic Malignant Syndrome (NMS) has been reported in association with administration of antipsychotic drugs, including olanzapine.
  • Tardive Dyskinesia
    A syndrome of potentially irreversible, involuntary, dyskinetic movements may develop in patients treated with antipsychotic drugs.

PRECAUTIONS

  • General:
    Olanzapine may induce hypotension. Olanzapine has not been evaluated or used to any appreciable extent in patients with a recent history of myocardial infarction or unstable heart disease. Patients with these diagnoses were excluded from premarketing clinical studies. Because of the risk of orthostatic hypotension with olanzapine, caution should be observed in cardiac patients
    During premarketing testing, seizures occurred in 0.9%. Olanzapine should be used cautiously in patients with a history of seizures or with conditions that potentially lower the seizure threshold
  • Laboratory Tests: No tests additional to routine ICU tests are indicated
  • Drug/Laboratory Test Interactions: None reported

IMPORTANT DRUG INTERACTIONS FOR THE ICU

  • Because of its potential for inducing hypotension, olanzapine may enhance the effects of antihypertensive agents.

ADVERSE REACTIONS

  • Body as a Whole:
    Fever
  • Cardiovascular System:
    Hypotension, Tachycardia, Hypertension
  • Digestive System:
    Dry mouth, Constipation, Dyspepsia, Vomiting
  • Nervous System:
    Somnolence, Dizziness, Tremor, Hypertonia

Critical Care Drug Manual

Print Friendly