Parkinson's Disease
Treatment Options
by Dr. Patrick Sweeney

A variety of other medications are available for the treatment of Parkinson's disease symptoms. The most powerful drug for treatment of Parkinson's symptoms is levodopa, a chemical found naturally in plants and animals.

Nerve cells can use levodopa to make dopamine, which replenishes the low amount in the brain. Levodopa is often used in combination with carbidopa (Sinemet) to prevent or diminish some of the side effects of the medication. However, there are concerns about the long-term side effects of levodopa, especially the development of involuntary movements (dyskinesias) which can be disabling.

Newer medications, such as the dopamine agonists, are much less likely to produce dyskinesias. Consequently, most experts recommend against using levodopa early in the course of the disease and to use dopamine agonists instead. If the patient cannot get sufficient relief with the dopamine agonists, particularly the newer generation of dopamine agonists, levodopa/carbidopa (Sinemet) can be added. Every attempt should be made to minimize the amount of levodopa taken.

Dopamine agonists, such as the newer generation ropinirole (Requip) and pramipexole (Mirapex), and the older agents, bromocriptine (Parlodel) and pergolide (Permax), are agonist drugs used to treat Parkinson's disease. These drugs mimic the role of dopamine in the brain and work by stimulating certain parts of the brain and nervous system.

They can also be used in combination with levodopa, but are generally less effective in controlling rigidity and bradykinesia. Most experts will use these medications first and only add levodopa if the symptoms cannot be controlled sufficiently.

One of the newer medications used to treat the symptoms of Parkinson's disease are tolcapone (Tasmar) and entacapone (Comtan). They are called COMT inhibitors because they block an enzyme that breaks down levodopa and dopamine. Alone, these medication are not helpful, but works well in combination with levodopa.

Tolcapone and entacapone slow the body's ability to get rid of levodopa so it lasts longer and is more consistent. Because they increases the effectiveness of levodopa, tolcapone and entacapone may also increase the side effects of levodopa, such as involuntary movements.

Tolcapone has been associated with liver failure, and thus rarely used. When tolcapone is used, frequent blood monitoring for liver damage is required. Other medications include amantadine (Symmetrel), selegiline (deprenyl), and the soon-to-be-released rasagiline.

Although research is ongoing, to date there is no known cure or preventative measure for Parkinson's disease.

It is important to realize that the patient's and physician's efforts should be focused on management of the disease. Through identifying individual symptoms and determining a proper course of action, most people with Parkinson's disease can live enjoyable, fulfilling lives.

The good news is that physicians have a much clearer profile of the condition, and are closer than ever to finding a cause-which may help find a cure.

Research in Parkinson's disease has made remarkable progress. There is very real hope that the causes, whether genetic or environmental, will be identified and the precise effects of these causes on brain function will be understood. These remarkable achievements give real hope for the future.