Parkinson disease (PD) is a
neurological disorder
PD occurs when
neurons in the substantia nigra (a part of the brain) die or become impaired
The neurons that die or become impaired produce
the neurotransmitter dopamine which allows smooth, coordinated function and movement of body muscles
Pathophysiology of PD
less dopamine --> less instructions to the brain --> movement problems (TRAP symptoms)
Symptoms of PD (TRAP)
tremor: when resting
rigidity: in legs, arms, trunk and face
akinesia/bradykinesia: lack of/ slow start in movement
postural instability: imbalance, falls
What can be used to measure involuntary movements from medications
The Abnormal Involuntary Movement Scale (AIMS)
Dopamine blocking drugs that can worsen PD
phenothiazines (prochlorperazine), butyrophenones (haloperidol), first and second generations antipsychotics, metoclopramide
Psychosis can occur with
advanced disease or can be due to side effects of drug treatment
Preferred antipsychotic for psychosis due to low risk of movement disorders
quetiapine
______ has a low risk of worsening movement disorders but has a high risk of seizures, agranulocytosis and other serious complications
clozapine
MOA of Nuplazid
5HT2A/2C receptor inverse agonist (FDA approved to treat hallucinations and delusions in PD)
Rapid withdrawal of levodopa or dopamine agonist can lead to a condition called
neuroleptic malignant syndrome (NMS)
Prodrug of dopamine and is the most effective agent
levodopa
Why is carbidopa given with levodopa
to prevent the peripheral metabolism of levodopa, which would destroy most of the drug before it crosses the blood-brain barrier
MOA of carbidopa/levodopa
levodopa is the precursor of dopamine, carbidopa inhibits dopa decarboxylase enzyme preventing peripheral metabolism of levodopa
Brand name of carbidopa/levodopa
Sinemet
if this test is positive, carbidopa/levodopa should be discontinued due to hemolysis risk
Coombs test
Brand name of carbidopa/levodopa ER
Rytary (can take whole or sprinkle on a small amount of applesauce)
Side effects of carbidopa/levodopa
can cause brown/black/dark discoloring of urine/saliva/sweat, priapism, orthostatis, psychosis, hallucinations, xerostomia
How many mg/day of carbidopa is required to inhibit dopa decarboxylase
70-100 mg/day
MOA of COMT inhibitors
increase the duration of action of levodopa; inhibit the enzyme catechol-O-methyltransferase (COMT) to prevent peripheral conversion of levodopa
Which drugs are COMT inhibitors
entacapone, opicapone, tolcapone
Brand name of entacapone
Comtan
Brand name carbidopa/levodopa/entacapone
Stalevo
How many of entacapone is needed with each dose of carbidopa/levodopa
200 mg PO
Brand name of opicapone
Ongentys
Brand name of tolcapone
Tasmar
Drugs thats are dopamine agonist
pramipexole, ropinirole, rotigotine, apomorphine
Brand name for pramipexole
Mirapex
Brand name of ropinirole
Requip XL
Brand name of rotigotine
Neupro (patch)
How to apply neupro (patch)
apply once daily at the same time each day to the stomach, thigh, hip, side of body, shoulder or upper arm; do not use the same site for at least 14 days
Which dopamine agonist is used as a "rescue" movement drug for "off" periods
apomorphine (injection)
MOA of amantadine
blocks dopamine reuptake into presynaptic neurons and increases dopamine release from presynaptic fibers, primarily used to treat TD associated with peak-dose of carbidopa/levodopa
Brand name for amantadine
Gocovri
amantadine can cause
cutaneous reaction called livedo reticularis (reddish skin mottling)
MOA of selective MAO-B inhibitors
blocks the breakdown of dopamine which increases dopaminergic activity
Drugs that are MAO-B inhibitors
selegiline, rasagiline, safinamide
Brand name selegiline
Emsam
Brand name of rasagiline
Azilect
What are centrally acting anticholinergics used for in PD
tremors
MOA of istradefylline
adenosine receptor antagonist
Brand name istradefylline
Nourianz
alpha/beta agonist that is used for neurogenic orthostatic hypotension
droxidopa
Brand name for droxidopa
Northera
While taking MAO-B inhibitors, what foods should you avoid
foods high in tyramine, including aged or matured cheese, air-dried or cured meats, sauerkraut, fava