Unit 7: CNS Drugs.Parkinson's Disease

Question 1

cause of Parkinson’s disease

Answer 1

depletion of dopamine-containing neurons in SUBSTANTIA NIGRA –> loss of normal inhibition

Question 2

symptoms of Parkinson’s

Answer 2

tremor
rigidity
bradykinesia = slow movement
postural instability
flexed hips/knees
short/shuffle steps

Question 3

how much dopamine is usually lost by the time a patient presents with symptoms?

Answer 3

70-80%

Question 4

what is the goal in Parkinson’s treatment?

Answer 4

correct imbalance of cholinergic neurons by REPLACING DOPAMINE

Question 5

What is the issue with Parkinson’s treatment?

Answer 5

dopamine does NOT cross the blood brain barrier

Question 6

name the drug classes used to treat Parkinson’s

Answer 6

dopaminergic agents
MAO-B inhibitors
anticholinergics
COMT inhibitors
miscellaneous

Question 7

Why are COMT inhibitors used to treat Parkinson’s?

Answer 7

COMT metabolizes levodopa

Question 8

What do MAO-B inhibitors do?

Answer 8

slow the breakdown of dopamine

Question 9

When are dopamine agonists used to treat Parkinson’s?

Answer 9

early: monotherapy
later: adjunct ot Levodopa

Question 10

MOA for Dopamine Agonists

Answer 10

direct stimulation of dopamine receptors

Question 11

Name 5 dopamine agonists

Answer 11

Bromocriptine
Pramipexole
Ripinirole
Roigotine
Apomorphine

Question 12

How long must a dopamine agonist be tried in order to see if it works?

Answer 12

4-8 weeks

Question 13

adverse effects of dopamine agonists

Answer 13

N/V
dizziness
hallucinations
daytime somnolence

Question 14

Why is Levodopa given?

Answer 14

Levodopa is a precursor to dopamine.
Dopamine does not cross the BBB.
Levodopa does

Question 15

Why is Carbidopa given with Levodopa?

Answer 15

If given alone, Levodopa would require HIGH doses because it gets decarboxylated (1-3% would make it to the brain).
When given together, Carbidopa decreases the required Levodopa dose by 75%.

Question 16

Does Carbidopa cross the BBB?

Answer 16

No

Question 17

Main effect of Carbidopa

Answer 17

increases the amount of Levodopa that makes it to the brain

Question 18

Expected effects of Carbidopa-Levodopa

Answer 18

improvement in bradykinesia

decreased mortality

Question 19

Carbidopa-Levodopa does NOT improve:

Answer 19

speech
postural instability
motor freezing
cognitive dysfunction

Question 20

When a patient is taking Carbidopa-Levodopa, when are the best results expected?

Answer 20

in the 1st few years of treatment

Question 21

adverse effects of Carbidopa-Levodopa

Answer 21

N/V
Depression
Anxiety
tachycardia
agitation
confusion
postural hypotension

Question 22

What metabolizes dopamine (hint: parkinson’s drug classes)

Answer 22

MAO-A
MAO-B
COMT

Question 23

COMT Inhibitors are used for ____

Answer 23

adjunct treatment for Parkinson’s

Question 24

MOA for COMT inhibitors

Answer 24

inhibit COMT, which metabolizes Levodopa –> Levodopa around longer

Question 25

name 2 COMT inhibitors

Answer 25

entacapone | tolcapone

Question 26

adverse effects of COMT inhibitors

Answer 26

N/D somnolence hallucinations

Question 27

How do the MAO-B inhibitors work?

Answer 27

metabolize dopamine selectively

Question 28

Name 2 MAO-B inhibitiors

Answer 28

selegiline | rasagiline

Question 29

Adverse effects of MAO-B Inhibitors

Answer 29

Nausea dizziness sleep disorders impaired gobnition

Question 30

MAO-B inhibitors interact with...

Answer 30

tramadol dextromethorphan cyclobenzaprine antidepressants

Question 31

Dietary advice for people taking MAO-B inhibitors

Answer 31

avoid tyramine containing foods

Question 32

Why should tyramine be avoided when taking MAO-B inhibitors?

Answer 32

MAO breaks down tyramine in the body; tyramine affects BP; too much tyramine can spike BP (medical emergency)

Question 33

What increases tyramine in foods?

Answer 33

tyramine occurs naturally in some foods and increases with age cooking does not decrease it

Question 34

Anticholinergics are used to treat what with Parkinson's?

Answer 34

drooling or tremors in early disease stages

Question 35

Name 2 anticholinergics used in Parkinson's treatment

Answer 35

benztropine | trihexyphenidyl

Question 36

What is important to remember about anticholinergic dosing with Parkinson's?

Answer 36

avoid abrupt discontinuation

Question 37

adverse effects of the anticholinergics used to treat Parkinson's

Answer 37

``` dry mouth constipation delirium confusion sedation urinary retention ```

Question 38

What is Amantadine used to treat?

Answer 38

dystonias in Parkinson's disease | uncontrollable muscle contraction that leads to repetitive movement or abnormal postures

Question 39

What effect are we hoping for with Amantadine treatment?

Answer 39

improvement in bradykinesia, rigidity, tremors

Question 40

What is the downside of Amantadine treatment?

Answer 40

drug loses effectiveness in 4-8 weeks --> TAPER off

Question 41

adverse effects of Amantadine

Answer 41

``` restlessness agitation GI disturbances urinary retention hypotension insomnia ```