olanzapine pamoate monohydrate: clinical use

Prescribing considerations

• Establish response and tolerability with oral olanzapine before initiating this formulation.
• Administer only by trained staff using deep intramuscular gluteal technique where observation and emergency care are available.
• Do not use when immediate control of acute agitation or severe psychosis is required.
• Account for prolonged persistence when changing treatment or managing adverse effects.
• Use caution with metabolic risk, hepatic impairment, seizures, cardiovascular disease, blood dyscrasias, anticholinergic-sensitive conditions and thromboembolism risk.
• Not indicated for people under 18 and not recommended for dementia-related psychosis or behavioural disturbance.

Contraindications and cautions

• Hypersensitivity to olanzapine or any excipient
• Known risk of narrow-angle glaucoma

Monitoring

• Observe after every injection for sedation, delirium and other features of excessive olanzapine exposure.
• Monitor weight, blood glucose and lipids.
• Assess blood pressure, movement disorders, sedation, mental state and adherence.
• Review smoking status and interacting medicines when response or tolerability changes.

Clinical pharmacology

Olanzapine antagonises dopamine, serotonin, muscarinic, histamine and alpha-adrenergic receptors. Slow dissolution of the pamoate salt provides sustained systemic exposure.

Formulation and product differences

• Powder and solvent require reconstitution to form a prolonged-release suspension.
• For deep intramuscular gluteal use only; do not administer intravenously or subcutaneously.
• Do not confuse with short-acting olanzapine powder for solution for injection.
• Every administration requires supervised observation because of post-injection syndrome risk.

Injection

Route: Parenteral

Strengths: 210 mg, 300 mg, 405 mg