There is no cure for Parkinson’s disease, but more than a dozen approved medicines treat symptoms and improve quality of life for Parkinson’s patients.
Standard therapy aims to resupplying dopamine to the brain in order to compensate for the loss of dopamine-producing cells. Levadopa and a number of drugs called dopamine agonists (drugs that work by increasing production or preventing breakdown of dopamine) are used in early Parkinson’s to control tremors and other motor symptoms. Over time, these medicines lose their effectiveness as more and more dopamine-producing cells die.
Research advances in the 2000s helped to introduce new types of dopamine agonists and add-on medicines that made treatment more effective and controlled symptoms longer. The most recent introductions include Exelon (rivastigmine), Azilect (rasagiline), and Mirapex ER (pramipexole).
Exelon, a cholinesterase inhibitor, was introduced in 2007 to treat dementia symptoms in Parkinson’s and Alzheimer’s patients. Azilect, approved in 2006, works by blocking the breakdown of dopamine. It is used alone or together with levodopa. Mirapex ER, approved in 2010, is a one-a-day dose form of the dopamine agonist drug, Mirapex. Recent studies have raised concerns that Mirapex might increase risk for heart failure. At this time, FDA recommends that patients continue to take Mirapex as prescribed; further investigations are underway.
New understanding about the disease process promises to improve therapy. The current view is that the earliest signs of Parkinson’s appear in areas of the brain including the medulla and olfactory bulb, which controls sense of smell. The disease gradually spreads to the substantia nigra in the midbrain where it disrupts motor functions.
This theory suggests that early symptoms like loss of smell and sleep disorders might help doctors predict the onset of Parkinson’s, treat the disease earlier, and possibly slow the development or lessen the severity of symptoms.
FDA: Drug Reference for FDA Approved Parkinson’s Disease Drugs
National Parkinson’s Foundation