Levodopa

Levodopa is the main way to treat symptoms. It raises the amount of dopamine in the brain. This can help ease problems like rigidity and slowness.

Common names are:

• Dopar
• Larodopa

People who take levodopa alone should not take vitamin B6 pills. It can speed up the breakdown of levodopa. Foods high in B6 may also need to be limited.

Levodopa and Carbidopa

Common names are:

• Carbidopa/levodopa
• Carbidopa/levodopa controlled-release
• Carbidopa/levodopa intestinal gel
• Carbidopa/levodopa/entacapone

The body breaks down levodopa quickly. Combining it with carbidopa can slow this breakdown.

These medicines may not work as well over time. How much or how often it is taken may need to be changed as the disease worsens.

Problems may be:

• Nausea and vomiting
• Coughing
• Nightmares
• Problems controlling urges

Entacapone, a COMT inhibitor (see below), may be added to levodopa/carbidopa. More side effects are listed below.

Dopamine Agonists

Common names are:

• Bromocriptine
• Cabergoline
• Pramipexole
• Ropinirole
• Apomorphine
• Rotigotine patch

These drugs act on the brain in a way that is like dopamine. They may be given alone as an early way to treat the disease. They may also be given with other medicines as the disease gets worse. These medicines last longer and do not have as many side effects.

Some problems are:

• Lightheadedness
• Drowsiness
• Dry mouth
• Nausea and vomiting
• Constipation
• Headache
• Ankle swelling
• Sudden low blood pressure
• Sudden need to sleep
• Seeing or hearing things that are not real
• Problems controlling urges

Cabergoline may also raise the risk of heart problems. And bromocriptine has rare but severe side effects, such as pulmonary fibrosis.

Monoamine Oxidase Type B Inhibitor

Common names are:

• Selegiline
• Rasagiline

Selegiline and rasagiline are often given with levodopa or levodopa/carbidopa. They work to stop the breakdown of dopamine in the brain.

Some problems are:

• Dry mouth
• Sudden low blood pressure
• Problems sleeping
• Nausea and vomiting
• Seeing things that are not real
• Nervousness

High doses of selegiline may cause a very high blood pressure when eating or drinking things that have tyramine, such as aged cheese and alcohol. Many medicines should also not be taken with selegiline and rasagiline. Reactions may happen.

COMT Inhibitors

Common names are:

• Tolcapone
• Entacapone

COMT inhibitors are taken with levodopa. They help slow the breakdown of levodopa.

These medicines can cause severe liver problems. Liver health tests will need to be done when taking it.

Some problems are:

• Dark urine
• Diarrhea
• Lightheadedness
• Headaches
• Drowsiness
• Confusion
• Seeing things that are not real

Anticholinergics

Common names are:

• Trihexyphenidyl
• Benztropine

These medicines can ease tremors and stiffness and improve muscle control.

Some problems are:

• Drowsiness
• Lightheadedness
• Sensitivity to bright lights
• Dry mouth
• Problems urinating
• Blurry eyesight
• Problems passing stool
• Fast heartbeat
• Mood changes
• Memory problems
• Confusion
• Seeing things that are not real

NMDA Antagonist

Common names are:

• Amantadine

Amantadine can help ease stiffness and tremors and improve muscle control. It may stop working when taken for a long time. It may be stopped and restarted to improve how it works.

Some problems are:

• Low blood pressure
• Confusion
• Blurry eyesight
• Lack of focus
• Dry mouth
• Purplish-red blotchy skin rash
• Depression
• Nightmares
• Problems sleeping
• Seeing things that are not real
• Problems urinating

Selective Serotonin Inverse Agonist (SSIA)

Common names are:

• Pimavanserin

Pimavanserin is an antipsychotic medicine. It is used to help people with psychosis from the disease. It blocks some serotonin receptors that cause these problems. It should not be taken by people with kidney, liver, or heart problems.

Problems may be:

• Nausea
• Swelling in the lower body
• Confusion

Adenosine A2a Inhibitor

Common names are:

• Istradefylline

Istradefylline is used with levodopa/carbidopa. It is given to people who have times when medicines are not working well and symptoms worsen.

Problems may be:

• Problems passing stool
• Nausea
• Lightheadedness
• Problems sleeping