ANTI-PARKINSONS DRUGS
Definition
• It is a chronic, progressive degenerative disorder, which impairs
the patient’s motor skills, speech and other functions.
• It belongs to a group of conditions called movement disorders.
Epidemiology
• PD prevalence increases with age. More common in men, than
in women. (male: female ratio between 2.3)
• Race group: Hispanics followed by non-Hispanic whites.
Causes of
Parkinson’s
Disease
Loss of dopaminergic neurons
from the substantia nigra,
leading to reduced production of
dopamine.
• https://youtu.be/pFLC9C-xH8E
Difference Between Parkinson’s Disease,
Parkinsonism and Schizophrenia.
Parkinson’s Disease
Parkinsonism
Schizophrenia
Due to little dopamine
No change in dopamine, usually induced by
drugs and toxins
Due to too much dopamine
Tremors, rigidity, stiffness, dysfunctional
posture etc.
Rapidly progressive and could have
additional features to the ones of
Parkinson’s disease such as hallucinations,
delusions and dementia.
Hallucinations and delusions.
Notable Figures With Parkinson’s Disease
Mohammad Ali
George Bush
Robin Williams
Treatment
Classification, MoA and ADRS
• Classification:
Replacing
dopamine
Dopamine agonists
Monoamine oxidase Catechol-O-Methyl
inhibitors
transferase (COMT)
inhibitors
Anticholinergic
drugs
levodopa with
DOPA
decarboxylase
inhibitors
Bromocriptine
Pergolide
Pramipexole
Ropinirole
Selegiline
Rasagiline
Benztropine
Biperidene
Trihexypheni
Tolcapone
Entacapone
•ADRs:
Drug
Adverse Effect
Levodopa
Nausea, sleepiness
Nonergot dopamine receptor agonists
Orthostatic hypotension, hepatic dysfunction
MAO-B Inhibitors
Sleeplessness, dry mouth
Anticholinergics
Constipation, blurry vision, confusion
NMDA Antagonist
Anxiety, Delirium
COMT inhibitors
Dyskinesia, vomiting
Test Your Knowledge !
• Parkinson disease is marked by a lack of which chemical in the brain?
A. Serotonin
B. GABA
C. Dopamine
D. Norepinephrine
E. None of the above
c
Test Your Knowledge !
• GG is a 63-year-old male who was diagnosed with Parkinson’s disease (PD) two years ago
with a primary symptom of uncontrollable tremor. He was well controlled with
amantadine up until recently when his disease progressed with increasing rigidity and
bradykinesia. The neurologist has decided to prescribe dopamine agonist for GG. Patient
counseling to GG regarding dopamine agonist therapy should include which of the
following? (Select all that apply.)
A. Delusions and hallucinations are more common with dopamine agonists compared to
levodopa
B. Dopamine agonists have been shown to slow disease progression
C. Doses should be tapered slowly if therapy is discontinued
D. Involuntary movements (dyskinesias) are more common with dopamine agonists
compared to levodopa
E. Sleep attacks similar to narcolepsy are a potential side effect
• A, C and E
Test Your Knowledge !
• Reason that dopamine itself is not used to treat in Parkinson's
disease:
A) too expensive
B) the problem is cholinergic in nature
C) dopamine does not cross the blood-brain barrier
D) levodopa has a higher affinity for the D2 receptor
Test Your Knowledge !
• Antiviral drug found to have anti-Parkinson's properties:
A) procyclidine
B) pergolide
C) amantadine
D) Levodopa
E) reserpine
•C
References
• https://www.parkinson.org/understanding-parkinsons/what-isparkinsons
• https://www.pharmacology2000.com/Central/Parkinson/exam1frame
.htm#m3
• https://www.ncbi.nlm.nih.gov/books/NBK536722/
• https://www.sciencedirect.com/topics/pharmacology-toxicology-andpharmaceutical-science/parkinson-disease