Parkinson’s Disease Medications: A Complete Guide

Parkinson’s disease cannot be cured, but different types of medications can help treat its symptoms.

Parkinson’s is best known for causing symptoms related to movement (known as “motor symptoms”), such as tremors, muscle stiffness, slow movement (bradykinesia), and impaired balance. But it can also cause nonmotor, or nonmovement, symptoms, such as dementia; psychosis, or loss of contact with reality; mood disorders such as depression, anxiety, and apathy; and sleep disorders such as insomnia.

Many of the symptoms of Parkinson’s are the result of a loss of neurons in the brain that produce the neurotransmitter (or chemical messenger) dopamine.

Not surprisingly then, many of the treatments for Parkinson’s disease either raise the level of dopamine in the brain or attempt to mimic its effect.

Medications for Parkinson’s disease fall into three general categories:

• Medications that increase the level of dopamine in your brain
• Medications that affect other neurotransmitters, to help control motor symptoms
• Medications that help control nonmotor symptoms

Dopamine-Focused Medications

The following prescription drugs help to regulate the amount of dopamine in the brain.

Dopamine-Increasing Medication

Dopamine can’t be taken directly as a treatment because it’s broken down in the body before it reaches the brain. As a result, the most common and effective treatment of motor symptoms related to Parkinson’s disease is a combination of the drugs levodopa and carbidopa.

This drug combination, sometimes called L-DOPA, eventually becomes dopamine that your brain can use. The levodopa can temporarily help replace some of the lost dopamine in the brain, and the carbidopa helps improve the uptake of levodopa by preventing it from being activated into dopamine before it reaches the brain.

In 2024, the U.S. Food and Drug Administration (FDA) approved two new levodopa and carbidopa medications for people with Parkinson’s disease.

To minimize the risk of dyskinesia, doctors often prescribe the lowest effective dose of levodopa and monitor patients for dyskinesia and other side effects over time.

Possible side effects of levodopa also include:

• Nausea
• Vomiting
• Sleepiness
• Orthostatic hypotension, or low blood pressure that occurs when sitting or standing up

In early Parkinson’s, taking levodopa with meals may decrease nausea.

However, in later stages of the disease, eating while taking the medication may decrease the drug’s effectiveness due to food competing with levodopa for absorption from the gut.

Certain drug treatments have been developed specifically to treat these off episodes. These include Inbrija, an orally inhaled form of levodopa, and istradefylline (Nourianz), a medication taken alongside levodopa.

• Fever
• Rigid muscles
• Unusual body movements
• Confusion

For this reason, you should never change your dose of levodopa or stop taking it suddenly without first talking to your doctor.

Dopamine-Mimicking Drugs

Dopamine agonists are medications that mimic the action of dopamine in the brain and can have side effects similar to those of levodopa.

• apomorphine (Apokyn, Kynmobi)
• pramipexole (Mirapex)
• rotigotine (Neupro)
• bromocriptine (Parlodel)
• droxidopa (Northera)

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• ropinirole (Requip)

People who are in the early stages of Parkinson’s disease should talk with their doctor about the potential benefits and risks of these medications before starting any of them due to individual risk factors.

MAO-B Inhibitors

These medications include rasagiline (Azilect), safinamide (Xadago), and selegiline (Emsam).

Sometimes, a MAO-B inhibitor is taken with levodopa to prolong the effect of that drug.

Common side effects of MAO-B inhibitors include:

• Mild nausea
• Dry mouth
• Lightheadedness
• Constipation

Taking these drugs at the same time as certain antidepressants and sedatives should be avoided or monitored closely by your doctor because of potentially dangerous interactions.

MAO-B inhibitors are considered less effective than levodopa at improving mobility in early Parkinson’s and are additionally associated with a higher risk of drug discontinuation because of side effects.

COMT Inhibitors

These medications help stop another enzyme that breaks down dopamine in the brain, catechol-O-methyltransferase (COMT). This group of drugs includes entacapone (Comtan), opicapone (Ongentys), and tolcapone (Tasmar).

The most common side effect of COMT inhibitors is diarrhea. They may also cause sleep disturbances, dizziness, or hallucinations.

Tasmar has been shown to cause severe liver disease in some people, so you may need to undergo regular blood tests to assess your liver function if you take it.

Amantadine (Symmetrel)

Amantadine (Symmetrel) is an antiviral medication that may increase the effects of dopamine in the brain. Researchers are unsure why amantadine helps in this area.

Medications That Affect Other Neurotransmitters

Other medications target different neurotransmitters to mitigate symptoms of Parkinson’s.

Anticholinergics 

This group of drugs includes trihexyphenidyl (Artane), benztropine (Cogentin), scopolamine (Transderm-Scop), and ethopropazine (Parsidol).

Side effects of anticholinergics may include:

• Blurred vision
• Dry mouth, constipation
• Urinary retention

Medications Treating Nonmovement Symptoms

While many medications focus on motor symptoms that are a hallmark of Parkinson’s disease, a host of drugs are also used to help various nonmotor or nonmovement symptoms of Parkinson’s disease.

Antipsychotics

Antidepressants 

Before prescribing an antidepressant, your doctor will want to know about any herbal supplements that you take, as well as any drug and alcohol use, since antidepressants may interact with these substances (and with some drugs for Parkinson’s disease).

Stimulants 

If a sleep disorder persists in spite of efforts to address underlying causes (like pain or frequent urination), then your doctor may prescribe a medication like modafinil (Provigil) to reduce sleepiness during the day.

Cholinesterase Inhibitors 

Medications like donepezil (Aricept), rivastigmine (Exelon), memantine (Namenda), and galantamine (Razadyne) were developed for Alzheimer’s disease, but they may also help with dementia in people with Parkinson’s.

The Takeaway

• Parkinson’s disease is a chronic illness, but medications can help lessen symptoms.
• There are three key types of medications used to treat Parkinson’s disease.
• These medications may increase the level of dopamine in your brain, affect other neurotransmitters, or help control motor and nonmotor symptoms