Unit 7: CNS Drugs.Parkinson's Disease Flashcards

1
Q

cause of Parkinson’s disease

A

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

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2
Q

symptoms of Parkinson’s

A
tremor
rigidity
bradykinesia = slow movement
postural instability
flexed hips/knees
short/shuffle steps
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3
Q

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

A

70-80%

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4
Q

what is the goal in Parkinson’s treatment?

A

correct imbalance of cholinergic neurons by REPLACING DOPAMINE

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5
Q

What is the issue with Parkinson’s treatment?

A

dopamine does NOT cross the blood brain barrier

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6
Q

name the drug classes used to treat Parkinson’s

A
dopaminergic agents
MAO-B inhibitors
anticholinergics
COMT inhibitors
miscellaneous
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7
Q

Why are COMT inhibitors used to treat Parkinson’s?

A

COMT metabolizes levodopa

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8
Q

What do MAO-B inhibitors do?

A

slow the breakdown of dopamine

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9
Q

When are dopamine agonists used to treat Parkinson’s?

A

early: monotherapy
later: adjunct ot Levodopa

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10
Q

MOA for Dopamine Agonists

A

direct stimulation of dopamine receptors

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11
Q

Name 5 dopamine agonists

A
Bromocriptine
Pramipexole
Ripinirole
Roigotine
Apomorphine
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12
Q

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

A

4-8 weeks

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13
Q

adverse effects of dopamine agonists

A

N/V
dizziness
hallucinations
daytime somnolence

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14
Q

Why is Levodopa given?

A

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

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15
Q

Why is Carbidopa given with Levodopa?

A

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%.

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16
Q

Does Carbidopa cross the BBB?

A

No

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17
Q

Main effect of Carbidopa

A

increases the amount of Levodopa that makes it to the brain

18
Q

Expected effects of Carbidopa-Levodopa

A

improvement in bradykinesia

decreased mortality

19
Q

Carbidopa-Levodopa does NOT improve:

A

speech
postural instability
motor freezing
cognitive dysfunction

20
Q

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

A

in the 1st few years of treatment

21
Q

adverse effects of Carbidopa-Levodopa

A
N/V
Depression
Anxiety
tachycardia
agitation
confusion
postural hypotension
22
Q

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

A

MAO-A
MAO-B
COMT

23
Q

COMT Inhibitors are used for ____

A

adjunct treatment for Parkinson’s

24
Q

MOA for COMT inhibitors

A

inhibit COMT, which metabolizes Levodopa –> Levodopa around longer

25
Q

name 2 COMT inhibitors

A

entacapone

tolcapone

26
Q

adverse effects of COMT inhibitors

A

N/D
somnolence
hallucinations

27
Q

How do the MAO-B inhibitors work?

A

metabolize dopamine selectively

28
Q

Name 2 MAO-B inhibitiors

A

selegiline

rasagiline

29
Q

Adverse effects of MAO-B Inhibitors

A

Nausea
dizziness
sleep disorders impaired gobnition

30
Q

MAO-B inhibitors interact with…

A

tramadol
dextromethorphan
cyclobenzaprine
antidepressants

31
Q

Dietary advice for people taking MAO-B inhibitors

A

avoid tyramine containing foods

32
Q

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

A

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

33
Q

What increases tyramine in foods?

A

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

34
Q

Anticholinergics are used to treat what with Parkinson’s?

A

drooling or tremors in early disease stages

35
Q

Name 2 anticholinergics used in Parkinson’s treatment

A

benztropine

trihexyphenidyl

36
Q

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

A

avoid abrupt discontinuation

37
Q

adverse effects of the anticholinergics used to treat Parkinson’s

A
dry mouth
constipation
delirium
confusion
sedation
urinary retention
38
Q

What is Amantadine used to treat?

A

dystonias in Parkinson’s disease

uncontrollable muscle contraction that leads to repetitive movement or abnormal postures

39
Q

What effect are we hoping for with Amantadine treatment?

A

improvement in bradykinesia, rigidity, tremors

40
Q

What is the downside of Amantadine treatment?

A

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

41
Q

adverse effects of Amantadine

A
restlessness
agitation
GI disturbances
urinary retention
hypotension
insomnia