How does Parkinson's medication work?

What happens when you take your Parkinson's medication? We find out more.

Why do people with Parkinson's take medication?

Not enough dopamine in the substantia nigra

People with Parkinson’s don’t have enough of the chemical messenger dopamine.

Dopamine is made by brain cells in the part of the brain called the substantia nigra.

Parkinson’s symptoms appear when dopamine levels become too low.

Dopamine in a drug

You can’t take dopamine as a drug because it can’t get into your brain. There is a barrier between your blood and your brain called the blood-brain barrier. It stops bad things like bacteria getting into your brain.

Your body won’t let dopamine cross the blood-brain barrier so it can’t get into your brain.

Alternative treatment

That’s where common treatment for Parkinson’s comes in.

When you swallow a pill it goes down your throat and into your stomach. From there it gets into your bloodstream and travels around your body.

Parkinson’s drugs like levodopa can cross the blood-brain barrier, get into the brain and get to work.

Different Parkinson's drugs work in different ways


Levodopa drugs like Madopar can cross into the brain and then be converted into dopamine.

Dopamine agonists

Dopamine agonist drugs such as pramipexol trick your brain into thinking they are dopamine. This means they can mimic the way dopamine works which can reduce your symptoms.

MAO-B inhibitors

Monoamine oxidase type B is an enzyme that wrongly hoovers up dopamine that is not being used by your brain. MAO-B inhibitor drugs such as rasagiline stop this enzyme so that more dopamine becomes available to treat your symptoms.

COMT inhibitors

There is an enzyme that can break down levodopa medication and stop it from working. COMT inhibitors such as Comtess block that enzyme which can help levodopa to work more effectively.


Amantadine medication helps more dopamine to be released in the brain.


Anticholinergics such as Kemadrin block a chemical messenger called acetylcholine. It helps to send messages in the brain and from your nerves to your muscles.

Making your medication work for you

The best way to understand your medication is to monitor it.

Keep a diary or chart when your specialist team starts you on a new drug, changes your drugs or adjusts the dose or frequency. Record the dose and time you took the drug and what happened to your symptoms. This can help you decide together on how well the drug is working.