Nurses Compass
Drug Guide
Olanzapine Pamoate
Classification
Therapeutic: Antipsychotic, mood stabilizer
Pharmacological: Atypical antipsychotic
FDA Approved Indications
- Schizophrenia
Mechanism of Action
Olanzapine Pamoate blocks multiple neurotransmitter receptors in the brain, including dopamine D2 and serotonin 5-HT2A receptors, which helps correct the imbalance of neurotransmitters associated with schizophrenia.
Dosage and Administration
Adult: Typically administered via intramuscular injection every 2-4 weeks, based on individual response and tolerability. Dose titration is necessary to minimize adverse effects.
Pediatric: Not approved for pediatric use.
Geriatric: Use with caution in elderly patients, especially considering risk of mortality in elderly patients with dementia-related psychosis.
Renal Impairment: Adjust dose based on clinical response and tolerability.
Hepatic Impairment: Use with caution; no specific adjustments established.
Pharmacokinetics
Absorption: Absorbed slowly from the injection site, with peak levels occurring approximately 4 days after administration.
Distribution: Widely distributed in body tissues; crosses the blood-brain barrier.
Metabolism: Metabolized in the liver primarily via CYP1A2 and CYP2D6 pathways.
Excretion: Excreted mainly via hepatic metabolism; minimal renal excretion.
Half Life: Approximately 30 days (release phase characteristic, due to the depot formulation).
Contraindications
- Hypersensitivity to olanzapine or excipients.
- Current or prior presence of neuroleptic malignant syndrome.
Precautions
- Use cautiously in elderly patients, especially those with cardiovascular disease, risk of stroke, or metabolic syndrome.
- Monitor for sedation, metabolic changes, and movement disorders.
- Patients should be monitored for signs of post-injection delirium/sedation syndrome.
Adverse Reactions - Common
- Weight gain (Very common)
- Sedation (Common)
- Elevated blood glucose (Common)
- Elevated cholesterol (Common)
Adverse Reactions - Serious
- Neuroleptic malignant syndrome (Rare)
- Post-injection delirium/sedation syndrome (PDSS) (Rare, but potentially serious)
- Tardive dyskinesia (Low but significant over long-term use)
- D muffed mortality in elderly with dementia-related psychosis (Fatal)
Drug-Drug Interactions
- CNS depressants (enhanced sedation)
- Antihypertensives (additive hypotensive effect)
Drug-Food Interactions
- None specific
Drug-Herb Interactions
- None established
Nursing Implications
Assessment: Monitor mental health symptoms, metabolic parameters, movement disorders, and signs of sedation.
Diagnoses:
- Risk of falls secondary to sedation
- Risk for impaired glucose or lipid metabolism
Implementation: Administer intramuscular injections as prescribed. Observe patient post-injection for delirium or sedation.
Evaluation: Assess for symptom control and adverse effects, including neuroleptic malignant syndrome and metabolic changes.
Patient/Family Teaching
- Report any signs of sedation, movement disorders, or signs of infection immediately.
- Discuss the importance of adherence to injection schedules.
- Educate about signs of hyperglycemia and hyperlipidemia.
Special Considerations
Black Box Warnings:
- Increased mortality in elderly patients with dementia-related psychosis.
- Post-injection delirium/sedation syndrome (PDSS).
Genetic Factors: None specifically established.
Lab Test Interference: May affect blood glucose, lipid, and prolactin levels.
Overdose Management
Signs/Symptoms: Excess sedation, agitation, confusion, hypotension, extrapyramidal symptoms, possibly coma.
Treatment: Supportive care, monitoring vital signs, symptomatic treatment, and possibly hospitalization. No specific antidote.
Storage and Handling
Storage: Store at controlled room temperature between 20°C to 25°C (68°F to 77°F).
Stability: Stable until expiration date when stored properly.