Apomorphine

Dopamine agonists
Dopamine agonists

Fast subcutaneous dopamine agonist used as rescue for sudden «off» episodes in Parkinson disease. Never with 5-HT3 antiemetics such as ondansetron.

Updated Nov 1, 2026

Also called: Apomorphine hydrochloride

Quick facts

Group: Dopamine agonists
Target: Dopamine receptors (D1 and D2 families)
Used for: Acute
Key effects: Nausea and vomiting · Yawning · Dyskinesia
Monitor: Blood pressure lying and standing · Injection sites
ATC: N04BC07

No doses: the clinician sets them by the current guideline.

Mechanism of action

Dopamine receptors (D1 and D2 families)Apomorphine

The figure shows apomorphine bound to the human dopamine D1 receptor coupled to its G protein; apomorphine also stimulates D2-like receptors.

Target in 3D: Dopamine receptors (D1 and D2 families). PDB structure 7JVQ (RCSB PDB, public domain). View the structure at RCSB PDB

Apomorphine is a non-ergot dopamine agonist that stimulates several dopamine receptor subtypes, acting in place of the missing dopamine in the striatum. Given under the skin it is absorbed within minutes, so it reverses an «off» episode quickly, but its effect is short. It also stimulates the chemoreceptor trigger zone, which is why it is so emetogenic.

Subcutaneous injection, absorbed within minutes
Stimulates striatal dopamine receptors in place of dopamine
The «off» episode is reversed quickly, for a short time
Stimulation of the vomiting centre: strong nausea

Indications

Acute, intermittent treatment of «off» episodes in advanced Parkinson disease, on demand or by continuous subcutaneous infusion Parkinson disease →

Adverse effects

Common

Nausea and vomiting (severe at the start)
Yawning, drowsiness and runny nose
Injection-site soreness, redness, bruising or itching
Dizziness and orthostatic hypotension
Dyskinesia

Contraindications

5-HT3 antagonists: ondansetron, granisetron, dolasetron, palonosetron, alosetron
Hypersensitivity to apomorphine or its excipients, including sodium metabisulfite

Key interactions

5-HT3 antagonists (ondansetron and others): Profound hypotension and loss of consciousness: contraindicated.
Dopamine-blocking antiemetics (haloperidol, metoclopramide, prochlorperazine): May worsen parkinsonism and block apomorphine.
Other drugs that prolong the QT interval: Additive QTc prolongation.
Alcohol, antihypertensives, vasodilators and sublingual nitroglycerin: Greater falls in blood pressure; alcohol is avoided and the patient lies down around nitroglycerin use.

What is monitored

Blood pressure lying and standing, especially at the first dose and after increases
ECG when there are risk factors for QT prolongation
Nausea and vomiting
Injection sites
Sleepiness, hallucinations and compulsive use

Administration and safety

Subcutaneous use only: never intravenous (crystals, thrombosis, pulmonary embolism).
The first dose is given in a supervised medical setting.
Rotate sites; the solution must be clear and colourless, not green or cloudy.
The label advises starting an antiemetic such as trimethobenzamide a few days before; 5-HT3 antiemetics are never used.
Pen or pump devices are primed and used as the manufacturer instructs.

Pregnancy and breastfeeding

Data are limited; pregnancy or breastfeeding is reported to the treating doctor.

Nursing care

At the first dose, measure blood pressure lying and standing and watch for fainting.
Check the medication list for ondansetron or other 5-HT3 antagonists.
Teach site rotation and to inspect the solution before each injection.
Ask about sudden sleep, hallucinations, falls, chest pain and prolonged erection.

Pharmacokinetics

Absorption: Rapid after subcutaneous injection; peak levels within an hour.
Metabolism: Route in humans not fully known: sulfation, N-demethylation, glucuronidation and oxidation are possible; it also auto-oxidises.
Half-life: About 40 minutes.
Onset and duration: Within minutes, which suits on-demand rescue use.

Test yourself

Think of the answer, then tap the question to see it.

Which antiemetics are contraindicated with apomorphine, and why?

5-HT3 antagonists such as ondansetron: profound hypotension and loss of consciousness were reported.

Why must apomorphine never be given intravenously?

It can crystallise in the vein and cause thrombus formation and pulmonary embolism.

What is apomorphine used for in Parkinson disease?

Rapid rescue of acute «off» episodes, given subcutaneously.

Which ECG change can apomorphine cause?

Dose-related QTc prolongation, with a risk of torsades de pointes.

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Connections

← Back to the class: Dopamine agonists

Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.

Sources: DailyMed - APOMORPHINE HYDROCLORIDE- apomorphine hydrochloride injection (DailyMed (U.S. National Library of Medicine), 2022); Apomorphine Injection: MedlinePlus Drug Information (MedlinePlus (U.S. National Library of Medicine), 2025); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026).

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Representative model, for educational purposes only.