Here are the basics about each of the medicines below. Only the common reactions are listed.

Medicine is used to raise dopamine or make the brain think it is getting enough dopamine. Medicines may need to be changed over time as the disease gets worse or side effects happen.

Prescription Medicines

Levodopa

  • Dopar
  • Larodopa

Levodopa and carbidopa

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

Dopamine agonists

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

Monoamine oxidase type B inhibitor

  • Selegiline
  • Rasagiline

COMT inhibitors

  • Tolcapone
  • Entacapone

Anticholinergics

  • Trihexyphenidyl
  • Benztropine

NMDA antagonist

  • Amantadine

Selective serotonin inverse agonist (SSIA)

  • Pimavanserin

Adenosine A2a inhibitor

    Prescription Medicines

     

    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
    REFERENCES:

    Burack M, Aldred J, et al. Implementing levodopa-carbidopa intestinal gel for Parkinson disease: insights from US practitioners. Mov Disord Clin Pract. 2018;5(4):383-393.

    FDA approves new add-on drug to treat off episodes in adults with Parkinson's disease. US Food and Drug Administration website. Available at: https://www.fda.gov/news-events/press-announcements/fda-approves-new-add-drug-treat-episodes-adults-parkinsons-disease. Published August 27, 2019. Accessed February 24, 2020.

    Homayoun H. Parkinson Disease. Ann Intern Med. 2018 Sep 4;169(5):ITC33-ITC48.

    Parkinson disease. EBSCO DynaMed website. Available at:https://www.dynamed.com/condition/parkinson-disease. Updated October 4, 2019. Accessed February 24, 2020.

    Parkinson disease. Merck Manual Professional Version website. Available at: http://www.merckmanuals.com/professional/neurologic-disorders/movement-and-cerebellar-disorders/parkinson-disease. Updated December 2018. Accessed February 24, 2020.

    Parkinson's disease. American Association of Neurological Surgeons website. Available at: http://www.aans.org/en/Patient%20Information/Conditions%20and%20Treatments/Parkinsons%20Disease.aspx. Accessed February 24, 2020.

    Parkinson's disease information page. National Institute of Neurological Disorders and Stroke website. Available at: https://www.ninds.nih.gov/Disorders/All-Disorders/Parkinsons-Disease-Information-Page. Updated August 28, 2019. Accessed February 24, 2020.

    Last reviewed November 2019 by EBSCO Medical Review Board Rimas Lukas, MD  Last Updated: 1/27/2021