T3-Parkinson's Disease Medications-MJ Flashcards
What are the cardinal symptoms of Parkinson’s?
Tremor
Rigidity
Postural instability
Slowed movements
Tremor, rigidity, postural instability, and slowed movements are all motor muscular symptoms of Parkinson’s. What are some “other symptoms”?
Depression
Psychosis
Eventually leads to dementia
What does Parkinson’s disease eventually lead to?
Dementia
What are the 5 early symptoms of Parkinson’s?
Decreased smell Increase salivation Clumsiness of hands Micrographia Decrease voice volume
What is micrographia?
Small handwriting
What is the pathophysiology of Parkinson’s?
The substantia nigra (black substance) is part of the EPS. The substantia nigra is the part that is broken. Neurons from this region release DOPAMINE to another part. So when the substantia nigra is broken/dying, there is DECREASED dopamine and INCREASE acetycholine
What are possible treatment options for Parkinson’s?
Increase dopamine
Decrease Ach levels
Or try doing both
What are some of the challenges when trying to treat Parkinson’s?
“off times”
Drug-induced dyskinesias (ticks)
Loss of effect (the wear off)
What does “off time” mean when referring to Parkinson’s treatment?
The drug randomly stops working for a period of time
What are the major drug classes for Parkinson’s?
Levodopa/carbidopa
Dopamine agonists
MOA-B inhibitors
Why can’t we just give dopamine to the patient with Parkinson’s when that is all they need?
Dopamine can’t cross BBB easily, and even if it could it has a short half life!
Does dopamine cross BBB easily?
No
Does dopamine have a long or short half life?
Short
Levodopa: Can this drug cross the BBB?
Yes!
Levodopa: What happens when levodopa crosses the BBB into the CNS?
Levodopa is accepted into dopaminergic receptors where it gets converted into dopamine
Why do we have to add Carbidopa with levodopa?
Once levodopa is converted to dopamine, it can spread into the periphery. Adding carbidopa allows this to not happen as much. This keeps the dopamine in the brain (where we want it), which allows us to decrease the dose, which in turn, decreases the side-effects (cardiovascular)
How effective is the levodopa/carbidopa combo?
VERY; there is a 50% reduction in Parkinson’s symptoms
T or F: Levodopa/carbidopa combo is so effective that if a client doesn’t respond, maybe they don’t have Parkinson’s. Maybe they were mis-diagnosed.
TRUE
How long does it take for the levodopa/carbidopa combo to work?
Several months before it reaches full effect!
After 5 years or so, the drug won’t work anymore. It does not last forever
What are the major side-effects of the levodopa/carbidopa combo?
N/V Dyskinesias Postural hypotension Dyshrythmias Impulse control
Levodopa/carbidopa: N/V
What happens if the patient is experiencing a lot of N/V. What can we suggest?
- Suggest to the patient to talk to their prescriber about temporalrly lowering their dose until their bodies adjust
- Take the drug with a LOW protein snack
Levodopa/carbidopa: N/V
Why should the patient take low protein snack instead of high?
Low protein will slow down the absorption so N/V will decrease. Taking too much protein will cause competion with the levodopa and slows the transport of levodopa through the BBB
Levodopa/carbidopa: Dyskinesias
What can we suggest to the patient if they are experiencing too much of this?
Tell them they may need to talk to their provider about lowering their dose
Levodopa/carbidopa: Postural hypotension
What should we suggest to the patient if they are experiening this?
Tell them the importance of increasing sodium and water levels. This will add more fluid to the vascular space, so the patient doesn’t get dizzy when they stand
Levodopa/carbidopa: Why do Parkinson’s patients have similar symptoms to schizophrenic patients?
Schizophrinic patients are thought to have problems due to increase dopamine. Having the lev/car combo may add more dopamine than we want and that can cause some psychosis symptoms
Can we give an antipsychotic to a patient with Parkinsons? Antipsychotics block dopamine??
Yes, we can. But only certain kinds!
Why can’t we give a first generation antipsychotic to help treat psychosis symptoms?
They will block too much dopamine
What antipsychotic drugs can we give to help treat the psychosis symptoms without it having major interactions?
Second generation antipsychotics!
Clozapine (remember agranulocytosis) and Quetiapine
What are the three major interactions when giving levodopa/carbidopa combo?
- First generation antipsychotics
- MAOI
- High protein meals
Why can’t we give a MAOI when giving the lev/car combo?
Way too much dopamine; MAOI will totally prevent the destruction of dopamine causing levels to increase too high
Why can’t patients eat high protein meals when taking the lev/car combo?
Protein competes with levodopa and slows the transport of levodopa through the BBB
What is the patient education we should give when talking about the lev/car combo mixed with protein?
It is still important to have adequate protein in the diet but instead of eating high protein meals, spread out the daily protein evenly throughout the day
Dopamine agonists: These aren’t dopamine drugs, but they activate ______ receptors.
Dopamine
What are the pros of dopamine agonists?
- No enzyme issue
- No dietary protein interactions
- Fewer dyskinesias
What are the cons of dopamine agonists?
- Not as effective (as lev/car)
- Hallucinations
- Daytime sleepiness
- Postural hypotension
What are the two kinds of dopamine agonists?
Ergot derived
Nonergot derived
Dopamine agonists: Which is better–ergot derived or nonergot derived. Why?
Nonergot derived; they are more selective–they activate fewer receptors
What are the dopamine agonists UNUSUAL SIDE-EFFECTS?
Impulse control disorders!
Dopamine agonists unusual side-effects: What are some examples and what should we teach the patient?
Gambling, shopping, hyper sexuality
This usually occurs after 9 months of treatment. If a patient already has problems with this, it is IMPORTANT for them to understand this unusual side-effect.
Patient education about this to the family and patient MUST BE KNOWN
What do MOA-B inhibitors do?
Increase dopamine
What is the example of the MOA-B inhibitor given in the PPT?
Selegiline
MOA-B: Why is selegiline good?
Very low risk of hypertensive crisis (what we usually would see with MAOIs)
MOA-B: What is the main side effect of selegiline?
Insomnia
MOA-B: If a younger patient is diagnosed with Parkinson’s, why may we start them on selegiline instead of one of the other drugs?
There is some thought that selegiline protects some of the neurons in the brain that are being attacked. There is no evidence to support this. but there is a CHANCE that there may be some neuroprotection so we start them on this one just in case there is neuroprotection
