There are approximately 5 million people globally living with Parkinson's disease, for which there is no cure. Parkinson's disease currently affects 1 in 100 people over the age of 60. Most people who get Parkinson's are aged 50 and over but younger people can get it too.
Parkinson's disease is a progressive neurological condition; a disorder of the central nervous system that is caused by a loss of cells from various parts of the brain. A part of the brain, substantia nigra, whose cells produce dopamine, is affected. Dopamine is responsible for coordination of movement and loss of dopamine is the cause of Parkinson's disease patients being less able to direct or control their movements. Without dopamine people can find that their movements become slower and it takes more time for them to do things.
Different patients have different symptoms but the most identifiable are motor symptoms, which include resting tremor, rigidity (unusual stiffness in a limb or body part) and bradykinesia (slowness of movement). Other symptoms can include mood disorders such as depression and anxiety, as well as tiredness, pain and constipation.
Patients experience "OFF" episodes, typically characterized by bradykinesia and akinesia (no movement). There are four different types of "OFF" episodes:
Morning "OFF" (considered the hardest to treat)
Levodopa, a medication that helps the brain to produce dopamine, is effective for a few years to prevent "OFF" episodes. Over time however, it loses its efficacy, which results in patients having more "OFF" episodes. These can typically occur from 1 to up to 6 times a day. An alternative option to levodopa is apomorphine.
Apomorphine is a drug used to treat Parkinson's disease symptoms. It is a type of dopamine agonist and is currently only given as a painful, highly acidic subcutaneous injection or via infusion.
It is usually prescribed for late-stage Parkinson's patients, particularly if levodopa is no longer working for them. Apomorphine is helpful in patients who have sudden or unpredictable changes in their symptoms, and suffer from severe "OFF" periods.
Apomorphine is considered to be the "gold standard" drug for treating "OFF" periods.