What Are the Newest Drugs for Parkinson’s?

Parkinson's disease is a brain disorder that causes movement problems like a slow, shuffling walk, loss of balance and coordination, and tremors. The newest drugs for Parkinson's are adenosine A2a antagonists and other therapies.

Parkinson’s disease is a brain disorder that causes movement problems like a slow, shuffling walk, loss of balance and coordination, and tremors. Anyone can get Parkinson’s, though it usually occurs in older people.

Parkinson’s disease is caused by changes in your brain. Movement is controlled by nerve cells that release a chemical called dopamine. In people with Parkinson’s, these nerve cells die and cause reduced levels of dopamine, leading to problems with nerve signals and muscle movement.  

Your brain also loses nerve endings that make norepinephrine, which is a brain chemical that controls your blood pressure and heart rate. 

Clumps of proteins called Lewy bodies also collect in the brain and cause dementia: memory loss and trouble thinking. Studies suggest gene changes might cause these proteins to clump together and cause Parkinson’s disease. Exposure to toxins and head injuries might also be risk factors for Parkinson’s disease. 

There is no cure for Parkinson’s disease, but medications, therapy, and lifestyle changes can improve your symptoms. Medications raise your dopamine levels, change other brain chemical levels, and treat other symptoms like blood pressure, constipation, and trouble sleeping.  

Levodopa 

Almost everyone with Parkinson’s disease will eventually end up taking levodopa, which is an amino acid precursor to dopamine. Your cells absorb the medicine and convert it to dopamine, so it raises your dopamine levels.

It’s often used in combination with another drug called carbidopa that slows down dopamine conversion in your blood so that more of it reaches your brain. Carbidopa also stops common side effects of levodopa like nausea and vomiting. 

Levodopa also commonly causes a condition called dyskinesia, where you have uncontrollable and jerky movements. Another side effect is called the “on-off” phenomenon, where you quickly switch between moving and being unable to move. 

Brand names of levodopa-carbidopa drugs include:

• Sinemet
• Parcopa
• Duopa
• Rytary
• Stalevo

Dopamine agonists

Dopamine agonists stimulate areas of your brain that use dopamine, so it has a similar but milder effect as levodopa. 

Dopamine agonists can cause hallucinations where you see things that aren’t there, though, and experience compulsive urges like an impulse to gamble or shop excessively. They can also make you sleepy, dizzy, and nauseous.

Common dopamine agonist drugs include:

• Pramipexole 
• Pramipexole dihydrochloride
• Ropinirole
• Apomorphine hydrochloride

COMT inhibitors

Catechol-O-methyltransferase (COMT) inhibitors block the COMT enzyme that breaks down levodopa in your body. It’s common to need higher doses of levodopa as your disease gets worse and more cells die, so COMT inhibitors can be used to prolong its effects. They’re often used in later stages of Parkinson’s to stop levodopa from wearing off so quickly.

These inhibitors include:

• Entacapone
• Tolcapone
• Entacapone-levodopa
• Opicapone 

Anticholinergic drugs

These medications don’t change your dopamine levels. Instead, anticholinergic drugs block a brain chemical called acetylcholine that affects movement. These medications can help with tremors and uncontrollable muscle contractions.

Types of anticholinergic drugs include benztropine and trihexyphenidyl hydrochloride. 

MAO-B inhibitors

Monoamine oxidase type B is an enzyme that breaks down dopamine and other brain chemicals. Inhibitor drugs block the enzyme, which makes more dopamine available to your brain. MAO-B inhibitors are often used in early stages of Parkinson’s and can be used alone or with levodopa and dopamine agonists. 

These medicines are called:

• Selegiline
• Selegiline hydrochloride
• Rasagiline
• Safinamide

Research for new Parkinson’s drugs and therapies is ongoing. Most people live a long time with Parkinson’s disease, which means you might take medications for a long time. All of these main treatments cause side effects that are hard to live with, so new drugs to treat those side effects are also being studied.

Adenosine A2a antagonists

This medication was approved by the FDA in 2019 for Parkinson’s disease as additional treatment alongside levodopa. It works by blocking a protein called the adenosine A2 receptor, which increases dopamine signaling. These medications lower off time and uncontrollable, jerky movements. 

Other therapies

There are clinical trials and research happening for other therapies, including:

• Stem cell therapy that uses healthy cells to repair damage from Parkinson’s
• Growth factors, which are proteins that support nerve cells and promote growth and survival 
• Gene therapy to reprogram cells to stay healthy and work better for longer
• Drugs for side effects like NLX-112 that targets certain serotonin receptors

There is no cure for Parkinson’s disease, but treatment can ease your symptoms. Your doctor will tailor treatment to your symptoms and your disease stage. If you think you have Parkinson’s disease symptoms, talk to your doctor.