Chapter 69: Parkinson's Disease Flashcards
Parkinson’s Disease occurs when
neurons in the substantia nigra die or become impaired
The cells in the substantia nigra produce which NT?
Dopamine - which allows smooth, coordinated function of body muscles and movement
What are the TRAP major symptoms of PD (due to less dopamine)
Tremor - when resting
Rigidity - in legs, arms, trunk and face (mask-like face)
Akinesia/bradykinesia - lack of/slow start in movement
Postural instability - imbalance, falls
What can be used to measure involuntary movements (i.e., tardive dyskinesias) from medications
The Abnormal Involuntary Movement Scale (AIMS)
Which drugs can worsen PD
Any drugs that block DA such as:
- Phenothiazines (e.g., prochlorperazine) used for psychosis, nausea, agitation
- Butyrophenones (e.g., haloperidol, droperidol) used for psychosis and behavior disorders or nausea
- FGA and SGA (e.g., risperidone at higher doses, paliperidone); lowest risk with quetiapine
- Metoclopramine, a renally-cleared drug that can accumulate in elderly patients
Even with high doses of PD drugs and various combinations, the disease will progress, including extended periods of “off time.” What does this mean
When symptoms of the disease worsen before the next dose of medication is due
Patients with PD have a high incidence of ___
depression. SSRIs or SNRIs are commonly used for treatment
Besides SSRIs and SNRIs, what other treatments can be used for depression in PD
TCAs (preferably secondary amines like desipramine and nortiptyline) and the DA agonist pramipexole
What is the preferred antipsychotic drug for PD psychosis & why
Quetiapine; low risk of movement disorders, but it can cause metabolic complications, including increased cholesterol and BG
pimavanserin is indicated for what?
a 5HT2A/2C receptor inverse agonist
to treat hallucinations and delusions in PD
T/F: levodopa and dopamine agonist do NOT need to be tapered
false
must taper - risk of life-threatening condition similar to NMS
What is the most effective treatment for PD
Levodopa (a prodrug of DA)
What medication is given with Levodopa & what is the combination called (brand name)
Carbidopa
Sinemet
Why is carbidopa given with levodopa
To prevent the peripheral metabolism of levodopa, which would destroy much of the drug before it crosses the BBB
Which drug class is used commonly for initial treatment in younger patients and eventually used in most patients with PD
DA agonists
Tremor-predominant disease in younger patients can be treated with a ______
Centrally-acting anticholinergic
beers criteria for elderly individuals
Which drug is a precursor of dopamine
levodopa
sinemet generic name
carbidopa/levodopa
What is the MOA of carbidopa
Inhibits dopa decarboxylate enzyme, preventing peripheral metabolism of levodopa
What is the starting dose for Sinemet IR
25/100 mg PO TID
T/F: Sinemet ER tablet CAN be cut in half
True
T/F: Rytary (carbidopa/levodopa ER capsule) can be sprinkled on a small amount of applesauce
True
What is a CI for Sinemet
Non-selective MAO inhibitors within 14 days, narrow angle glaucoma
Side effects of Sinemet
Nausea, dizziness, orthostasis, dyskinesias, hallucinations, psychosis
Can cause brown, black, or dark discoloring of urine, saliva or sweat and can discolor clothing; positive Coombs test: discontinue drug (hemolysis risk); unusual sexual urges, priapism
How many mg/day of carbidopa is required to inhibit dopa decarboxylate
70-100
Long-term use of Sinemet can lead to
fluctuations in response and dyskinesias
MOA of COMT inhibitors
increase the duration of action of levodopa; inhibit the enzyme COMT to prevent peripheral conversion of levodopa
Which drug is a COMT inhibitor
Entacapone, opicapone, tolcapone
COMT inhibitors should only be used with ____
levodopa
Dosing for entacapone
200 mg PO with each dose of carbidopa/levodopa
Dopamine agonist MOA
act similar to DA at the DA receptor
Which medications are dopamine agonists
Pramipexole, Ropinerole, Rotigotine
Generic name for Mirapex, Mirapex ER
pramipexole
Brand name for ropinerole
Requip
Generic name for Neupro
rotigotine
Dopamine agonist warnings
Somnolence (including sudden daytime sleep attacks), orthostasis, hallucinations, dyskinesias
Which Dopamine Agonist comes as a patch
Rotigotine (Neupro)
How should Neupro be used
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
Rotigotine should be avoided if a patient has a sensitivity/allergy to ____
sulfites
T/F: Rotigotine patch does not need to be removed before an MRI
False
Which drug is a dopamine agonist injection for advanced disease (a “rescue” movement drug for “off” periods)
Apomorphine (Apokyn)
Where must the first dose of apomorphine be administered in?
Medical office (a test dose)
Contraindication for apomorphine
Do not use with 5HT3 antagonists (e.g., ondansetron) due to severe hypotension and loss of consciousness
Side effects of apomorphine
Severe nausea/vomiting, hypotension
For emesis prevention, what can be given with apomorphine 3 days prior to initial dose
trimethobenzamide (Tigan)
MOA of amantadine
blocks DA reuptake into presynaptic neurons and increases DA release from presynaptic fibers. Primarily used to treat dyskinesias associated with peak-dose of Sinemet
Amantadine warnings
Somnolence, psychosis
Amantadine side effects
dizziness, orthostatic hypotension, livedo reticularis (reddish skin mottling - can require drug d/c)
Which medications are selective MAO-B inhibitors used in PD
Selegiline, rasagiline, safinamide
Which MAO-B should not be taken at bedtime due to activating effects
Selegiline
MOA of MAO-B inhibitors
block the breakdown of DA which increases dopaminergic activity
CI of MAO-B inhibitors
Use in combination with other MAOi (including linezolid), opioids, SNRIs, TCAs
Warnings of MAO-B inhibitors
Serotonin syndrome, hypertension
Which centrally acting anticholinergic medications are used in PD
Benztropine and trihexyphenidyl
Cogentin generic name
benztropine
Side effects of benztropine
anticholinergic SEs: dry mouth, constipation, urinary retention, blurred vision, somnolence, confusion
Droxidopa is used for neurogenic orthostatic hypotension. What are the side effects
Syncope, falls, HA
MOA-B inhibitors should not be used with foods high in tryamine such as
aged or mature cheese, air-dried or cured meats, including sausages and salamis, saurkraut, fava or broad bean pods, tap/draft beers, soy sauce
rasagiline is ____ substrate
what should be done with inhibitor?
CYP1A2
limit dose to 0.5mg with cipro (or other 1A2 inhibitors)
