Parkinsons Disesae Flashcards
What’s the role of substantia nigra that dies or becomes impair in PD?
Dopamine (that’s why there’s a dopamine shortage in PD)
What’s Parkinson’s Dx (PD)?
Brain disorder that occurs when neurons in a part of the brain called the substantia nigra die or become impaired
Primary s/sx of PD?
TRAP
Tremor - seen during rest, usually worsened by anxiety
Rigidity - arms, legs, trunk and face (mask-like face)
Akinesia/bradykinesia - lack of movement or slow initiation of
movement
Postural instability - poor balance, which may lead to freq falls
Other signs of PD?
Small, cramped handwriting (micrographia)
Shuffling walk
Stiff facial expression, reduced eye blinking
Muffled speech, drooling, dysphagia
Depression, anxiety (psychosis in advanced dx)
Constipation, incontinence
What’s frustrating and challenging about PD complications?
Eventually, even with high doses of the 2 most effective classes of drugs (Carbidopa/Levodopa and dopamine agonists) the “off” periods will increase
What has the highest efficacy for tx in PD pts with depression?
Tricyclic antidepressants
Whats preferred antipsychotic in PD pts (psychosis can present with advanced dx)?
Quetiapine (low risk of movement disorders, but will require monitoring due to metabolic complications, including blood glucose & cholesterol)
List drugs that may induce PD (drug-induced PD)?
Phenothiazines (Prochlorperazine, etc)
FGAs (esp, haloperidol)
SGAs (Risperidone (Risperdal) at higher doses)
Metoclopramide (Reglan) - dopamine blocking agent
Which agent is most commonly used and most effective and is sometimes tolerated for initial tx in elderly?
Carbidopa-Levodopa (Sinemet)
What could be used for initial tremor in younger pts?
Anticholinergic
Amantadine
MOA of Carbidopa/Levodopa?
Carbidopa Inhibits dopa decarboxylase, preventing peripheral metabolism of levodopa
(Levodopa is a precursor of dopamine)
Brand name of Carbidopa/Levodopa
Sinemet
Sinemet CR
T/F? Sinemet SR tab can be cut into half?
T
But don’t crush or chew
How much Carbidopa is required to inhibit peripheral conversion (dopa decarboxylase) and to reduce nausea?
70-100mg of Carbidopa
SEs of Sinemet (Carbidopa/Levodopa)?
Nausea
Dizziness
Orthostasis
Dyskinesia (abnormal movement)
Brown, black or dark urine, saliva or sweat and discolor clothing
Sinemet (Carbidopa/Levodopa) and unusual sexual urges?
Sinemet (Carbidopa/Levodopa) may cause unusual sexual urges, priapism
Effect of Long-term use of Sinemet (Carbidopa/Levodopa)?
Response may fluctuate after long-term use
What does Sinemet (Carbidopa/Levodopa) need to be separated from?
Iron
May be protein
MOA of COMT-INHIBITOR?
Inhibit enzyme COMT to prevent peripheral and central conversion of levodopa
Role of COMT-inhibitor in therapy?
Used only with levodopa to increase levodopa duration of action
COMT-inhibitor agents?
Entacapone (Comtan)
Levodopa/Carbidopa + Entacapone (Stalevo)
Brand name of Entacapone? (COMT-inhibitor agent)
Comtan