Parkinsons

Question 1

What is the primary drug to treat parkinsons & why?

Answer 1

Levodopa - it can cross the blood brain barrier, once it enters the brain it is transformed into dopamine by an enzyme

Question 2

Why can dopamine not be injected as a medication for parksinsons?

Answer 2

If dopamine was administered orally or parenterally (injection, infusion) then it would be ineffective because it can not cross the BBB

Question 3

Why would a parkinsons patient be taking both levodopa & carbidopa?

Answer 3

If levodopa is given with a peripheral decarboxylase inhibitor aka carbidopa, levodopa will reduce the amount that gets converted in the periphery (outside of the CNS)

Question 4

How does the dosage of levadopa change when it is given with carbidopa aka Sinemet?

Answer 4

Using carbidopa with levodopa allows a much smaller dosage of levodopa to be administered to limit side effects

Question 5

What is a major side effect of levadopa that is common when first starting?

Answer 5

Orthostatic hypotension: pts should be observed closely in therapy for this

Question 6

What side effect of levadopa occurs after taking levadopa for an extended time (3 mo- several years)

Answer 6

Dyskinesias (very frustrating for pt, so must find right dosage)

Question 7

Why can levadopa & carbidopa cause behavioral changes?

Answer 7

Dopamine is important in controlling mood and behavior, which is what the drugs are adding to the CNS

Question 8

Why may a patient with parkinsons not begin taking levadopa, but instead another drug and what guidelines would be followed to initiate taking levadopa?

Answer 8

Becomes less effective when its taken for a prolonged period of time (3-4 years) - This progresses to the point that the drug is ineffective.

once the sx are impairing function

Question 9

Define the on-off phenomenon

Answer 9

Effectiveness of levodopa suddenly and spontaneously decreases resulting in worse parkinsonian symptoms caused by dec dopamine levels – this is the “off” phase
-The on-off phases can occur repeatedly throughout the day

Question 10

A patient is having side effects that are too severe and are no longer tolerating the parkinsons drug. What may be a suggestion a doctor could make?

Answer 10

a drug holiday to let the body recover from any drug toxicity or tolerance due to prolonged high dose use of levodopa

Question 11

What parkinsons drugs is typically used in addition to levadopa when it has become less effective or significant on-off, but has major side effects?

Answer 11

Dopamine agonists

Question 12

What parkinsons drug impacts cholinergic pathways, but is only successful when used with levadopa?

Answer 12

Anticholinergic drugs

Question 13

What antiviral medication can be used in conjunction with levadopa?

Answer 13

Amantadine

Question 14

What drug is used during the early stages of parkinsons and is thought to slow down the progression?

Answer 14

MOA-B inhibitors

Question 15

How do MOA-B inhibitors work to decrease parkinsons symptoms?

Answer 15

MOA-B enzyme breaks down dopamine in the brain
These drugs inhibit this enzyme which allows for dopamine to have a longer effect in the brain

Question 16

T/F MOA-B inhibitors interact with specific foods?

Answer 16

False- MOA inhibitors do

Question 17

What drug (not carbidopa) can also be used to enable more levadopa to reach the brain and not get converted in the periphery?

Answer 17

Catechol-O-Methyltransferase (COMT)

Question 18

What is the peak time of levadopa?

Answer 18

1 hour after administration

Question 19

What are appropriate rehab guidelines for parkinsons patients?

Answer 19

Aggressive balance exercises, gait training and strengthening exercises are essential in promoting health and function in patients with Parkinson disease as the need for meds can reduce with good PT