Achievable logoAchievable logo
PTCE
Sign in
Sign up
Purchase
Textbook
Practice exams
Feedback
Community
How it works
Exam catalog
Mountain with a flag at the peak
Textbook
Introduction
1. Medications
2. Patient safety and quality assurance
3. Order entry and processing
4. Federal requirements
Wrapping up
Achievable logoAchievable logo
1.4.7.5 Parkinson's disease
Achievable PTCE
1. Medications
1.4. Medications by organ system
1.4.7. Drugs of the nervous system

Parkinson's disease

2 min read
Font
Discuss
Share
Feedback

Parkinson’s disease is a common degenerative disease of the brain characterized by tremors, rigidity or stiffness of muscles, and difficulty with balance. It is caused due to the loss of dopamine secreting neurons in the part of the brain called substantia nigra. Many drugs are available to manage Parkinson’s disease, with carbidopa-levodopa being the cornerstone of therapy. Levodopa is converted to dopamine in the brain, while carbidopa prevents breakdown of levodopa so that enough levodopa can be delivered to the brain from the bloodstream.

Substantia Nigra
Substantia Nigra

Table showing drugs used to treat Parkinson’s disease and their mechanism of action

Mechanism of action Generic name and common brands
Increase dopamine levels in the brain Carbidopa-levodopa (Sinemet, Parcopa, Rytary, Dhivy)
Dopamine agonists that mimic the action of dopamine Apomorphine (Apokyn, Kynmobi), pramipexole (Mirapex), ropinirole (Requip), rotigotine (Neupro)
MAO-B inhibitors that block the breakdown of dopamine Rasagiline (Azilect), selegiline (Carbex, Eldepryl)
COMT inhibitors that block the breakdown of dopamine Entacapone (Comtan), tolcapone (Tasmar), opicapone (Ongentys)
Anticholinergics that block the action of neurotransmitter acetylcholine Benztropine (Cogentin), trihexyphenidyl (Artane)
Adenosine receptor antagonist Istradefylline (Nourianz)
Increase dopamine levels in the brain Fos Levodopa-fos carbidopa (Vyalev, Produodopa)
Unknown mechanisms Amantadine (Osmolex, Gocovri, Symmetrel)

Common adverse effects include nausea, vomiting, dizziness, headache, sleepiness, postural hypotension, confusion, hallucinations, delusions, agitation, and dry mouth. Urinary retention, dry mouth, and cognitive dysfunction are more common with anticholinergics.

Sign up for free to take 5 quiz questions on this topic

All rights reserved ©2016 - 2025 Achievable, Inc.