Parkinson Disease

Question 1

Pathophysiology of PD

Answer 1

Neurons in the substantia nigra die or become impaired
These cells usually produce dopamine
When 80% of these cells die, symptoms of the disease appear

Question 2

Parkinson disease symptoms

Answer 2

TRAP
Tremor
Rigidity
Akinesia/Bradykinesia
Postural Instability

Question 3

What scale is used to measure involuntary movements from medications?

Answer 3

Abnormal Involuntary Movement Scale (AIMS)

Question 4

What medications can worsen PD?

Answer 4

Phenothiazines (Prochlorperazine) used for psychosis, nausea, agitation
Butyrophenones (haloperidol, droperidol) used for psychosis and behavior disorders or nausea
First and second generation antipsychotics (risperidone, paliperidone)
Metoclopramide

Question 5

What comorbid condition commonly occurs with PD?

Answer 5

Depression

SSRIs, SNRIs, TCAs, pramipexole

Question 6

What is the antipsychotic of choice for PD? Why?

Answer 6

Quetiapine

Low risk of movement disorders but can cause metabolic complications including increased cholesterol and BG

Question 7

What medications are used to treat PD?

Answer 7

Carbidopa/Levodopa
Entacapone
Pramipexole
Ropinerole
Apomorphine
Amantadine
Selegiline
Rasagiline
Safinamide
Benztropine

Question 8

What is the primary treatment principle for PD?

Answer 8

Replace dopamine

Question 9

Why is carbidopa given with levodopa

Answer 9

To prevent peripheral metabolism of levodopa

Question 10

Why is levodopa the most effective agent for PD?

Answer 10

It is a prodrug of dopamine

Question 11

Carbidopa/levodopa MOA

Answer 11

Levodopa is a precursor to dopamine - replenishes dopamine

Carbidopa - inhibits dopa decarboxylase enzyme, preventing peripheral metabolism of levodopa

Question 12

Carbidopa/levodopa CI, SE, and notes

Answer 12

CI: Non-selective MAOi within 14 days, narrow angle glaucoma
SE: nausea, dizziness, orthostasis, dyskinesias, hallucinations, psychosis
Notes: 70-100mg/d carbidopa required to be effective

Question 13

Entacapone MOA

Answer 13

Increase duration of action of levodopa; inhibit enzyme COMT to prevent peripheral conversion of levodopa

Question 14

Pramipexole (Mirapex), Ropineral (Requip) MOA

Answer 14

Dopamine agonist

Question 15

Pramipexole (Mirapex) and Ropineral (Requip) warnings

Answer 15

Somnolence (sudden daytime sleeping attacks), orthostasis, hallucinations, dyskinesias

Question 16

Apomorphine indication, CI, SE, and notes

Answer 16

Indication: “rescue” movement drug for “off” periods; advanced disease
CI: do not use with 5HT-3 antagonist d/t severe hypotension
SE: N/V, hypotension
Must give test dose

Question 17

Amantadine MOA

Answer 17

blocks dopamine reuptake

Question 18

Amantadine warnings and SE

Answer 18

Warnings: Somnolence, psychosis
SE: dizziness, orthostatic hypotension, livedo reticularis (skin reaction)

Question 19

Selegiline, rasagiline, safinamide (selective MAO-Bi) MOA

Answer 19

block breakdown of dopamine

Question 20

Selective MAO-B inhibitor CI and warnings

Answer 20

CI: use in combo with other MAOi (including linezolid), opioids, SNRIs
Warnings: serotonin syndrome, HTN

Question 21

Benztropine (Cogentin) MOA and SE

Answer 21

MOA; anticholinergic and antihistamine effects - used for tremor
SE: anticholinergic

Question 22

Alpha/beta agonist Droxidopa (Northera) SE

Answer 22

syncope, falls, HA