Inclusion Criteria:  Subjects with PD according to the MDS Clinical diagnostic criteria for Parkinson's disease. Participants on antiparkinsonian medication in advanced stages of the disease and experiencing OFF periods and pain. Apomorphine treatment naïve subjects or not received any within the last six months. Stable PD and pain medications for at least 30 days. Competence to self-report pain severity in the King's Parkinson's disease Pain Scale and a Likert Visual Analogue Scale.  Exclusion Criteria:  Subjects who are unable to self-report pain severity in the selected scales. Patients that may require a translator or are illiterate will be included if they can self-report pain severity. Subjects with a diagnosis of dementia (Montreal Cognitive Assessment <20). Subject with poorly controlled orthostatic hypotension. Subjects associated with another medical condition, e.g., any cardiovascular, renal or hepatic impairment, hematological or psychiatric diseases.  Any contraindication to receiving apomorphine injections:  Subjects who are hypersensitive to apomorphine or any ingredient in the formulation or component of the container (hydrochloric acid concentrated, sodium bisulfite (E222), and water) Subjects using concomitant drugs of the 5HT3 antagonist class including (e.g., ondansetron, granisetron, palonosetron) Subjects using concomitant antihypertensive medications or vasodilators Subjects with prolonged QT on an electrocardiogram.