Parkinson's disease is a chronic, degenerative neurological disorder that affects one in 100 people over age 60. While the average age at onset is 60, some people are diagnosed at 40 or younger. There is no objective test, or biomarker, for Parkinson's disease, so the rate of misdiagnosis can be relatively high, especially when the diagnosis is made by a non-specialist. Estimates of the number of people living with the disease therefore vary, but recent research indicates that at least one million people in the United States, and more than five million worldwide, have Parkinson's disease.
While many Parkinson's patients report one or more family members with the disease, it is not always clear that one or several genes are the cause. Scientists currently believe that in the majority of cases, genetic and environmental factors cause Parkinson's disease. Research into this subject continues aggressively every day. Unfortunately, however, it is generally impossible to determine what specifically causes Parkinson's disease.
What are dopamine receptor agonists?
These medicines constitute a class of drugs used to treat Parkinson’s disease symptoms that mimic the action of naturally occurring dopamine. They stimulate dopamine receptors directly without being metabolized to another compound as is the case with levodopa. Although this class of medication is less potent than levodopa, they can be very beneficial in treating symptoms for long periods of time.
An array of medications can help treat Parkinson's disease and related conditions. Medications for Parkinson's disease fall into three general categories:
- Medications that increase the level of the neurotransmitter dopamine in your brain
- Medications that affect other neurotransmitters, to help control motor symptoms
- Medications to help control non-motor symptoms
Treating Parkinson's disease with medication can sometimes be a balancing act between managing the disease and managing drug side effects. Here are some medications that fall into the group of dopamine promoters:
- Bromocriptine – This blocks the production prolactin from the pituitary gland, stimulating dopamine receptors
- Amantadine – Amantadine is utilized for treating the side effects of Parkinson’s medications
- Cabergoline – it’s a powerful drug that mimics the activity of dopamine receptors in your brain
- Carbidopa/Levodopa – it’s used to treat tremors, spasms, poor muscle control and muscle stiffness
Medications That Increase Dopamine
The following categories of prescription drugs increase the amount of dopamine in the brain:
- Dopamine-like medication - The drug sold under the names Duopa, Parcopa, Rytary, and Sinemet (levodopa and carbidopa) forms the cornerstone of Parkinson's disease treatment.
- The combination of levodopa and carbidopa — sometimes referred to simply as levodopa, or L-dopa — eventually becomes dopamine that your brain can use.
Dopamine can't be taken directly as a treatment because it's broken down in the body before it reaches the brain. Levodopa is often very effective for managing tremors and other motor symptomsearly in the disease. If you take levodopa over a long period of time, you may experience involuntary twisting or writhing movements (dyskinesia), and possibly psychotic delusions or hallucinations. The effectiveness of levodopa may decrease after you've been taking it for some time, so you may need to take it more often to get the same results. You should never change your dose of levodopa, or stop taking it suddenly, without talking to your doctor.
Dopamine agonists - This group of drugs includes Apokyn (apomorphine), Mirapex (pramipexole), Neupro (rotigotine), Parlodel (bromocriptine), and Requip (ropinirole).
These medications mimic the action of dopamine in the brain and can have side effects similar to those of levodopa. They may be taken alone or with levodopa. In rare cases, these medications may cause an uncontrollable desire to gamble, go shopping, or have sex.
Whether you yourself are facing the challenge of Parkinson's disease, or are touched by the disease in some other way, every single person can play a role in the search for a cure. The answer is in all of us.