Parkinson’s Medications: Types, Benefits and Side Effects

Written and reviewed as a literature-based educational guide by Dr. Akbar Zaib, PhD in Neurosciences.
Last updated: August 2026.


Living with Parkinson’s can make medication choices and timing feel complicated. This guide explains the main types of Parkinson’s medications, how they help manage symptoms, and the important side effects patients and caregivers should know about.


Parkinson's medications

Medication is an important part of managing Parkinson’s disease. It can improve symptoms such as slowness of movement, stiffness, tremor and difficulty walking. However, Parkinson’s medications do not cure the disease or reliably stop its progression.

There is no single medication that is best for everyone. Treatment is selected according to a person’s symptoms, age, daily activities, other medical conditions and possible risk of side effects. The response to medication can also change as Parkinson’s progresses.

This guide explains the main types of Parkinson’s medications, how they work and the side effects patients and caregivers should know about.

Important: Parkinson’s medications should always be prescribed and adjusted by a neurologist or another qualified healthcare professional. Never stop or change a Parkinson’s medication without medical advice.


The main types of Parkinson’s medication

The principal medication groups are:

  1. Levodopa combined with carbidopa or benserazide
  2. Dopamine agonists
  3. MAO-B inhibitors
  4. COMT inhibitors
  5. Amantadine
  6. Anticholinergic medications

Some people take one medication, while others need a combination to manage different symptoms or reduce “off” time.

1. Levodopa

Levodopa is the most effective medication for the movement symptoms of Parkinson’s disease. It is especially helpful for slowness, stiffness and, in many people, tremor.

Dopamine itself cannot easily cross from the bloodstream into the brain. Levodopa can cross this barrier and is then converted into dopamine inside the brain.

Levodopa is normally combined with either:

  • Carbidopa, as in carbidopa–levodopa preparations
  • Benserazide, as in co-beneldopa preparations

Carbidopa and benserazide reduce the amount of levodopa that is converted into dopamine before reaching the brain. This allows more levodopa to reach the brain and helps reduce side effects such as nausea.

Levodopa is available in several forms, including immediate-release and extended-release tablets or capsules. Depending on the country and stage of Parkinson’s, inhaled, intestinal or continuous subcutaneous delivery options may also be available.

Possible side effects of levodopa

These can include:

  • Nausea
  • Dizziness or low blood pressure
  • Sleepiness
  • Confusion or hallucinations
  • Dyskinesia, meaning involuntary movements

After several years, some people experience a shorter response to each dose. Symptoms may return before the next dose is due. This is known as wearing-off.

People can also experience unpredictable changes between periods of good symptom control, called “on” time, and periods when symptoms return, called “off” time. These changes do not necessarily mean that levodopa has stopped working. The dose, formulation or timing may need to be reviewed.

2. Dopamine agonists

Dopamine agonists do not turn into dopamine. Instead, they imitate dopamine by stimulating dopamine receptors in the brain.

Common examples include:

  • Pramipexole
  • Ropinirole
  • Rotigotine
  • Apomorphine

Dopamine agonists may be used alone during the earlier stages of Parkinson’s or together with levodopa. They are generally less powerful than levodopa but may help reduce off time and smooth out symptom fluctuations.

Rotigotine is delivered through a skin patch. Apomorphine can be administered by injection or infusion and may be considered when a person experiences significant off periods.

Possible side effects of dopamine agonists

These can include:

  • Nausea
  • Dizziness and low blood pressure
  • Swelling of the legs
  • Hallucinations or confusion
  • Excessive daytime sleepiness
  • Sudden episodes of falling asleep
  • Dyskinesia when combined with levodopa

Dopamine agonists can also cause impulse-control disorders. A person may develop new or difficult-to-control behaviours involving gambling, shopping, eating, sexual activity or repetitive hobbies.

Patients and family members should report any unusual behavioural changes promptly. The person taking the medication may not always recognize the change themselves.

3. MAO-B inhibitors

Monoamine oxidase-B, or MAO-B, is an enzyme that breaks down dopamine in the brain. MAO-B inhibitors block this enzyme, allowing dopamine to remain available for longer.

Common examples include:

  • Rasagiline
  • Selegiline
  • Safinamide

MAO-B inhibitors may provide modest improvement in movement symptoms. They can sometimes be used alone during early Parkinson’s or added to levodopa to reduce off time.

They do not replace levodopa when stronger symptom control is needed.

Possible side effects of MAO-B inhibitors

These can include:

  • Nausea
  • Headache
  • Dizziness
  • Low blood pressure
  • Sleep disturbance
  • Confusion or hallucinations
  • Increased dyskinesia when combined with levodopa

MAO-B inhibitors may interact with certain antidepressants, pain medicines and other medications. A doctor or pharmacist should review all prescription medicines, over-the-counter products and supplements being used.

4. COMT inhibitors

Catechol-O-methyltransferase, or COMT, is an enzyme that breaks down levodopa. COMT inhibitors slow this process and help the effects of levodopa last longer.

Examples include:

  • Entacapone
  • Opicapone
  • Tolcapone

COMT inhibitors have little or no useful effect when taken without levodopa. They are normally added to levodopa when a person experiences wearing-off or insufficient symptom control between doses.

Because they increase and extend levodopa’s effect, the levodopa dose may sometimes need adjustment.

Possible side effects of COMT inhibitors

These can include:

  • Increased dyskinesia
  • Nausea
  • Diarrhoea
  • Dizziness
  • Confusion or hallucinations
  • Orange or reddish-brown urine discoloration

Urine discoloration associated with some COMT inhibitors is usually harmless.

Tolcapone has been associated with potentially serious liver injury and requires specific monitoring. It is used much less frequently than other medications in this class.

5. Amantadine

Amantadine was originally developed as an antiviral medication. It was later found to help some symptoms of Parkinson’s disease.

It may provide modest improvement in slowness, stiffness and tremor. Its most important current use is helping to control dyskinesia associated with levodopa treatment.

Possible side effects of amantadine

These can include:

  • Confusion
  • Hallucinations
  • Dizziness
  • Insomnia
  • Swelling of the ankles or legs
  • Dry mouth
  • Constipation
  • A mottled, purplish skin pattern called livedo reticularis

Older adults and people with impaired kidney function may be more vulnerable to adverse effects. The dose may need to be adjusted according to kidney function.

6. Anticholinergic medications

Anticholinergic medications were used more frequently before levodopa became available. Today, their role in Parkinson’s treatment is limited.

Examples include:

  • Trihexyphenidyl
  • Benztropine

These medicines may reduce tremor or dystonia in selected younger patients, but they provide relatively little benefit for slowness, balance or walking problems.

Possible side effects of anticholinergic medications

These can include:

  • Confusion
  • Memory problems
  • Hallucinations
  • Blurred vision
  • Dry mouth
  • Constipation
  • Difficulty urinating

Because of their effects on memory and thinking, anticholinergic medications are generally avoided in older adults and people who already have cognitive difficulties.


Parkinson’s Medication Comparison
Medication class Main purpose Important side effects or concerns
Levodopa Strongest overall treatment for movement symptoms Nausea, low blood pressure, dyskinesia and motor fluctuations
Dopamine agonists Mimic dopamine and may reduce “off” time Sleepiness, hallucinations and impulse-control disorders
MAO-B inhibitors Preserve dopamine and provide modest symptom relief Medication interactions, dizziness, insomnia and increased dyskinesia
COMT inhibitors Extend the effect of levodopa Diarrhoea, dyskinesia, confusion and urine discoloration
Amantadine Often used to help control dyskinesia Confusion, hallucinations, leg swelling and skin changes
Anticholinergics Limited use for tremor in selected patients Memory problems, confusion, constipation and urinary retention


Get Your Free Parkinson’s Medication Management Diary

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Medication timing, food and protein

Parkinson’s medications often work best when taken at consistent times. Even a relatively short delay can cause symptoms to return in someone who depends on precisely timed doses.

Food can affect levodopa differently from person to person. Taking it on an empty stomach may improve absorption, but it can also cause nausea.

Dietary protein contains amino acids that may compete with levodopa for absorption and transport into the brain. Some people notice that protein-rich meals reduce or delay the effect of a dose, while others experience no clear problem.

Do not remove protein from the diet without professional advice. Protein is essential for maintaining strength and general health. A neurologist or dietitian may recommend adjusting the timing or distribution of protein instead.

Related article: Best Time to Eat Protein With Levodopa: Research-Based Strategies for Parkinson’s Patients


Important medication safety points

People with Parkinson’s and their caregivers should remember the following:

  • Take each medication at the prescribed time.
  • Do not stop Parkinson’s medication suddenly.
  • Do not crush extended-release tablets unless a pharmacist confirms that it is safe.
  • Keep an updated medication list for medical appointments and emergencies.
  • Report hallucinations, severe dizziness, fainting or sudden sleep episodes.
  • Report new compulsive behaviours or personality changes.
  • Ask a pharmacist to check for medication and supplement interactions.
  • Tell hospital staff that Parkinson’s medication may be time-critical.

Stopping some Parkinson’s medications abruptly can cause severe symptoms and, in rare cases, a potentially dangerous withdrawal reaction. Medication changes should therefore be supervised.


Frequently asked questions

What is the best medication for Parkinson’s disease?

There is no single best medication for everyone. Levodopa generally provides the strongest improvement in movement symptoms, but the most appropriate treatment depends on symptoms, age, lifestyle, other medical conditions and susceptibility to side effects.

Does levodopa stop working after several years?

Levodopa normally continues to have an effect. However, as Parkinson’s progresses, each dose may last for a shorter period, and the response can become less predictable. Adjusting the dose, timing, formulation or accompanying medication may help.

Related article: Why Parkinson’s Medication Stops Working Sometimes

Should levodopa be delayed for as long as possible?

Levodopa should not automatically be delayed when symptoms affect quality of life. Concerns about future fluctuations must be balanced against the benefit of controlling symptoms now. This decision should be made with a Parkinson’s specialist.

Can Parkinson’s medication make symptoms worse?

A dose that is too high, too low or poorly timed can contribute to dyskinesia, off periods, dizziness, sleepiness, confusion or hallucinations. New or worsening symptoms should be discussed with the prescribing clinician rather than managed by changing the dose independently.

What should I do if I miss a dose?

Instructions can differ according to the medication and how late the dose is. Check the patient information leaflet or contact a pharmacist or healthcare professional. Do not automatically take two doses together.


Key takeaway

Parkinson’s medication can significantly improve movement, independence and quality of life, but treatment must be individualized. Levodopa remains the most effective option for movement symptoms, while dopamine agonists, MAO-B inhibitors, COMT inhibitors and other medicines can address particular symptoms or treatment complications.

Keeping a record of medication times, symptom changes, off periods and side effects can help the healthcare team make better treatment decisions.


References and further reading

  1. Parkinson’s Foundation. Prescription Medications.
    https://www.parkinson.org/living-with-parkinsons/treatment/prescription-medications
  2. Parkinson’s Foundation. Levodopa.
    https://www.parkinson.org/living-with-parkinsons/treatment/prescription-medications/levodopa
  3. National Institute for Health and Care Excellence. Parkinson’s Disease in Adults: Recommendations.
    https://www.nice.org.uk/guidance/ng71/chapter/Recommendations
  4. NHS. Parkinson’s Disease: Treatment.
    https://www.nhs.uk/conditions/parkinsons-disease/treatment/
  5. Parkinson’s Foundation. Dopamine Agonists.
    https://www.parkinson.org/living-with-parkinsons/treatment/prescription-medications/dopamine-antagonists
  6. Parkinson’s Foundation. MAO-B Inhibitors.
    https://www.parkinson.org/living-with-parkinsons/treatment/prescription-medications/mao-b-inhibitors
  7. Parkinson’s Foundation. COMT Inhibitors.
    https://www.parkinson.org/living-with-parkinsons/treatment/prescription-medications/comt-inhibitors
  8. Parkinson’s Foundation. Amantadine.
    https://www.parkinson.org/living-with-parkinsons/treatment/prescription-medications/amantadine
  9. Parkinson’s Foundation. Anticholinergic Drugs.
    https://www.parkinson.org/living-with-parkinsons/treatment/prescription-medications/anticholinergic-drugs

Medical disclaimer

This article is provided for general educational purposes and should not be considered medical advice. Parkinson’s medications can cause significant side effects and interactions. Never start, stop or change the timing or dose of medication without consulting a qualified healthcare professional.

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