apomorphine hydrochloride: clinical use

Prescribing considerations

• Initiate in a specialist setting after confirming a clinically useful response and acceptable tolerability.
• Confirm that the patient or carer can recognise OFF symptoms and safely administer the selected formulation.
• Review cardiovascular, pulmonary, renal, hepatic and neuropsychiatric status, postural hypotension, somnolence and previous impulse-control problems.
• Assess whether antiemetic treatment is required and review its cardiac risk and continuing need.
• Avoid abrupt withdrawal; monitor for dopamine agonist withdrawal syndrome or a neuroleptic malignant syndrome-like reaction.

Contraindications and cautions

• Ondansetron; Kynmobi also contraindicates co-administration with other 5-HT3 antagonists.
• Respiratory depression, dementia, psychotic disorder and hypersensitivity to apomorphine or excipients.
• Hepatic insufficiency for injectable APO-go products; hepatic impairment for Kynmobi.
• Severe levodopa-associated dyskinesia or dystonia for injectable APO-go products.
• Cankers or mouth sores for Kynmobi.
• Injectable APO-go products are contraindicated in people younger than 18 years.

Monitoring

• Supine and standing blood pressure, falls, syncope and cardiac symptoms.
• QT-risk factors and ECG when domperidone is used or cardiac risk changes.
• Blood count at regular intervals when apomorphine is used with levodopa.
• Injection sites or oral mucosa, depending on formulation.
• Hallucinations, psychosis, somnolence, sudden sleep onset, impulse-control disorders and dopamine dysregulation syndrome.
• Response during OFF episodes and reliability of the delivery device.

Clinical pharmacology

Apomorphine is a direct D1- and D2-receptor agonist. Subcutaneous administration is rapidly absorbed and cleared, while sublingual absorption is slower and produces lower peak exposure than the subcutaneous route. Metabolism is principally through sulphation and glucuronidation.

Formulation and product differences

• The pen provides intermittent subcutaneous injections for individual OFF episodes.
• The pre-filled syringe is a prediluted solution for continuous subcutaneous infusion by minipump or syringe driver; it is not for intermittent injection.
• The sublingual film is administered whole under the tongue and avoids needles but commonly causes local oral adverse effects.
• The injectable formulations contain metabisulphite and commonly cause local injection-site reactions; the film also contains metabisulphite and has formulation-specific mouth contraindications.

Solution for infusion

Route: Intravenous

Strengths: 5 mg/mL

Injection

Route: Parenteral

Strengths: 10 mg/mL