Parkinson's + alzheimer's

Question 1

Cause of parkinson’s

Answer 1

selective loss of dopaminergic neurons in substantia nigra

Question 2

Parkinson’s 4 cardinal signs + other symtpoms

Answer 2

• postural instability
• tremor
• rigidity
• bradykinesia
• mask like face
• freezing
• loss of smell
• depression + anxiety

Question 3

L-dopa MOA

Answer 3

• precursor for dopamine
• crosses BBB bc dopamine can’t, then broken down once in brain into dopamine
  -> increases dopamine therefore decrease motor symtpoms eg. bradykinesia, tremors, rigidity

-> must be taken with carbidopa/benserazide

Question 4

Carbidopa/benserazide class + MOA

Answer 4

• peripheral dopa-decarboxylase inhibitors
• inhibits enzymes AADC to prevent conversion of L-dopa to dopamine in the peripheries
• therefore more crosses BBB + can be broken down into dopamine

-> taken w/ L-dopa

Question 5

Basagiline/selegiline MOA

Answer 5

• MAO-B inhibitors
  -> decrease breakdown of dopamine in the CNS

Question 6

Entacapone MOA

Answer 6

• inhibits COMT to stop breakdown of L-dopa in periphery

Question 7

What is ‘wearing off’ and what does this look like for a patient + how to reduce this

Answer 7

• when medication X get person through to next dose
• motor symptoms gradually come back
• use modified release formula or lower dose more frequently

Question 8

Benzatropine class + MOA + adverse effects

Answer 8

• anticholinergic
• reverse the high ACh + lowe dopamine
• blocks ACh from binding to muscarinic receptors to decrease excessive cholinergic activity + reduce tremor
• dry mouth
• urinary retention

Question 9

Why do some antiemetics eg. metoclopramide need to be avoided in PD

Answer 9

• antiemetic = stop vomiting
• act as dopamine antagonists + cross BBB to prevent dopamine binding
• cause worsening of symptoms

Question 10

Rivastigmine MOA + adverse effects

Answer 10

• alzheimer’s = decreased ACh available
• rivastigmine decreases breakdown of ACh therefore delay degradation
• decreased HR
• increased parasympathetic activity

Question 11

Memantine class + MOA

Answer 11

• NMDA receptor antagonist
• targets elevated glutamate levels in AD
• blocks NMDA receptors
• prevents glutamate binding so reduces associated damage