Parkinsons Disease

Question 1

Treatment of tremors in PD

Answer 1

Antimuscarinics
Benztropine (cogentin)
used at low dose

Question 2

L-DOPA starting dose, SE, and clinical pearls
- must know structure

Answer 2

Starting dose: 25/100mg CD/LD PO BID-TID with meals

• First line for initial PD therapy

SE: Nausea/vomiting, LD motor fluctuations/ dyskinesias, hallucinations

Clinical pearls: increase absorption with food, titrate dose to balance efficacy and side effects

Question 3

how does carbidopa lower the dose of L-DOPA

Answer 3

L-DOPA is converted to dopamine in the SN but not in the periphery because carbidopa inhibits the convertion of L-DOPA to dopamine but carbidopa cannot cross BBB

Question 4

apomorphine (Apokyn) MOA

Answer 4

A mixed D1/D2 agonist
Can be administered subq in late stage PD to provide rapid relief of the off state

Question 5

DA receptor agonists: non-ergolines starting dose, clinical pearls and side effects

Answer 5

First line for initial PD therapy
Ropinirole (requip)
pramipexole (mirapex)
rotigotine (neuropro)
Apomorphine (apokyn)
SE: Nausea, vomiting, sudden onset sleep, hallucinations, ICD, Edema, orthostatic hypotention
Starting doses
pramipexole IR 0.125 mg PO
TID; ER 0.375 mg PO daily
- ropinirole IR 0.25 mg PO TID; ER 2 mg PO daily
- rotigotine 2 mg patch applied to the skin Q24H
- apomorphine 2 mg SC injection prn up to 5 x daily or 10 mg SL Film up to 5 x daily

Question 6

Inhibitors of dopamine metabolism

Answer 6

First line for mild symptoms
Second line for adjunct therapy
SE: nausea/vomiting, headache, insomnia, hypotension/hypertension
Starting dose:
Selegiline (deprenyl)
- 5mg PO BID
Rasagiline (Azilect)
- o.5mg PO daily

Question 7

reversible Inhibitors of dopamine metabolism

Answer 7

SE: nausea/vomiting, headache, insomnia, hypotension/hypertension

Safinamide (xadago)
- 50mg PO daily
used in adjunct to L-DOPA

Question 8

Treatment initiation

Answer 8

• Dopamine agonist for age < 60 and high risk of dyskinesia (uncontrolled movement)
• start with lowest effective dose

Question 9

When to avoid dopamine agonists as initial treatment

Answer 9

age > 70 OR
history of ICD OR
cognitive impairment OR
excessive daytime sleepiness OR
hallucinations

Question 10

Stepwise therapy

Answer 10

Initial treatment patient should be started on dopamine antagonist if less than age 60
if patient has one of the following start L-DOPA (older than 70, ICD, cognitive impairment, excessive daytime sleepiness, hallucinations)
if symptoms are not managed with dopamine antagonist add MAO-B inhibitor

Question 11

COMT inhibitors

Answer 11

In combination to manage symptom fluctuation (waring off)
Entacapone (comtan)
- 200mg PO with each LDOPA dose
Opicapone (ongentys)
- 50mg PO QHS
Tolcapone (tasmar)
- 100mg PO TID
SE: Nausea, vomiting, brown/orange urine, hepatotoxicity

Question 12

Amantadine (symmetrel)

Answer 12

management of LD motor fluctuations
SE: insomnia, confusion/hallucinations, livedo reticularis

Clinical pearls
- starting dose 100mg PO BID

Question 13

Anticholinergic

Answer 13

Benztropine (cogentin)
- 0.5mg PO QHS
Trihexyphenidyl (artane)
- 1mg PO daily
SE: confusion/ dementia, blurry vision, urinary retention, dry mouth, constipation