What medications treat Parkinson's disease?

Parkinson’s disease is a neurodegenerative disorder that primarily causes problems with movement, coordination, and balance. Other symptoms can include problems with speech and swallowing, depression, bladder control, and constipation. Parkinson’s disease most commonly occurs in people over the age of 60, though it does occur at younger ages in some cases.

There is no cure for Parkinson’s disease, and people with the condition will require ongoing care and treatment. Treatment focuses on managing symptoms and helping the person with the condition enjoy the best quality of life possible. Medications to reduce and control symptoms are a mainstay of treatment. Minimizing side effects from medications is also a focus.

Medications that treat Parkinson’s disease

Neurotransmitters are chemicals that allow nerve cells to communicate with one another. One of the most important neurotransmitters is dopamine, which is essential to many physical and cognitive functions—movement, attention, motivation, sleep, and others.

Parkinson’s disease causes brain cells that produce dopamine to deteriorate and die off. With Parkinson’s disease, this primarily occurs in the parts of the brain that control movement, which is why movement symptoms like tremors, muscle stiffness, and loss of balance are the major symptoms of the condition.

Treatment for Parkinson’s disease typically includes medications that improve dopamine levels, along with drugs to reduce side effects of these medications. These include:

Levodopa

The brain uses a natural chemical called levodopa to make dopamine. Taking medications that contain this substance can help improve dopamine levels and are the main treatment for Parkinson’s disease. This can help reduce symptoms. Levodopa therapy is available in several different formulations, including oral medications, infusions, and an inhaled version.

Carbidopa

Levodopa therapy can cause side effects, including low blood pressure, dizziness, nausea, and headaches. Because of this, levodopa therapy is typically given in combination with a medication called carbidopa, which helps reduce these side effects. Other medications may be used in place of carbidopa to reduce side effects.

Dopamine agonists

Nerve cells communicate using neurotransmitters and receptors—with some cells releasing neurotransmitters and other cells receiving those neurotransmitters. In order to receive a neurotransmitter, a cell needs a specific receptor, a physical component the neurotransmitter can bind to. Agonists are drugs that can bind to these receptors. Dopamine agonists bind to dopamine receptors and have a similar effect on the brain as dopamine.

Enzyme inhibitors

Enzymes are substances that speed up chemical processes inside cells, such as neurotransmitter signaling. Enzyme inhibitors slow down this process. Several enzyme inhibitors are used in the treatment of Parkinson’s disease:

• Type B monoamine oxidase (MAOB) inhibitors work by slowing the breakdown of dopamine.
• Catechol O-methyltransferase (COMT) inhibitors work by slowing the breakdown of levodopa to prolong the effects of the medication and reduce symptoms during “off” times. “Off”times are episodes where symptoms worsen between doses of medications.

Amantadine

This drug acts on the cells that release dopamine, increasing the amount that is released and also preventing those cells from reabsorbing dopamine. It can have multiple uses in treating Parkinson’s disease, reducing symptoms, reducing side effects from other medications, and treating “off” times.

Anticholinergic medications

Dopamine is not the only neurotransmitter at work in the brain. As Parkinson’s disease impairs the brain’s ability to produce dopamine, it creates an imbalance with the other neurotransmitters that are present. Anticholinergic medications block a neurotransmitter called acetylcholine. Doing this helps maintain balance and accommodate lower dopamine levels and helps reduce tremors. However, these medications carry a risk of serious side effects that should be discussed with a healthcare provider.

What to discuss with a healthcare provider

All of the medications mentioned above carry a risk of side effects, and side effects are a topic to discuss with a healthcare provider any time you or a loved one is starting a new treatment for Parkinson’s disease.

It’s also important to understand that the therapies used to treat Parkinson’s disease do not slow progression. Parkinson’s is a progressive disease where symptoms become more severe over time. Likewise, treatment will need to evolve and change over time. For questions about diagnosis, treatment, and support while living with Parkinson’s disease, your best source of information will be a healthcare provider.