Apomorphine

Trade names

• APOKYN
• IXENSE
• SPONTANE
• UPRIMA

Actions

• Activates D2-like receptors.
• To an order of magnitude lesser extent also activates D1-like receptors.
• Acts as a high affinity 5-HT2 and α-adrenergic receptor antagonist.

A morphine decomposition product, apomorphine does not contain morphine or its skeleton nor does it bind to opioid receptors.

Route of Administration

Subcutaneous injection

Bioavailability

100% following a SC injection

Plasma protein binding

~50%

Half-life

30-60 minutes

Metabolism

Hepatic

Elimination

Mainly biliary, only 3-4% is excreted unchanged in the urine.

Important side-effects

May worsen or precipitate delusions, hallucinations or psychosis.

Dyskinesias.

Excessive sleepiness.

Peripheral oedema.

Chest discomfort, angina.

Orthostatic hypotension.

Nausea and vomiting.

Recommended dose

Must be titrated on the basis of effectiveness and tolerance.

Start dose is usually at 0.2 mL (2 mg) and the maximum recommended dose is 0.6 mL (6 mg)

There is no evidence from controlled trials that doses greater than 0.6 mL (6 mg) give an increased effect.

Dose titration should take place in a setting where blood pressure can be closely monitored in both supine and standing position at 20, 40, and 60 minutes post dose. Patients that develop significant orthostatic hypotension should be excluded from treatment.

Renal impairment

The starting dose should be reduced to 1 mg when administrating apomorphine to patients with mild or moderate renal impairment.

Apomorphine is not recommended in patients with sevre renal failure.

Hepatic impairment

Apomorphine is contraindicatied in patients with severely impaired hepatic function.