3.3 Anti-Parkinson Drugs

Question 1

What environmental factor causes parkinson-like syndrome?

Answer 1

MPTP (dopamine neurotoxin)

Question 2

A balance between what activity controls voluntary movements?

Answer 2

Dopaminergic + Cholinergic Activity

Question 3

What was the first drug used to tx Parkinson’s?

Answer 3

Levodopa (L-dopa)

Question 4

What does the drug interaction of Levodopa with sympathomimetic drugs (b-agonists) cause?

Answer 4

Cardiac stimulation

Question 5

What does the drug interaction of Levodopa with Pyridoxine (vit B6) cause?

Answer 5

Dec efficacy of Levodopa

Question 6

What does the drug interaction of Levodopa with antipsychotic drugs cause?

Answer 6

Dec efficacy of levodopa

Question 7

What does the drug interaction of Levodopa with MAOI’s cause?

Answer 7

Hypertensive crisis

Question 8

What is the peripheral decarboxylase inhibitor?

Answer 8

Carbidopa

Usually given as Sinemet = levodopa + carbidopa

Question 9

What are the advantages of Carbidopa (Sinemet)?

Answer 9

• Inc 1/2 life of levodopa
• Dec peripheral side effects
• Diminished CNS (dopamine) fluctuations

Question 10

What are the disadvantages of Carbidopa (Sinemet)?

Answer 10

Increased CNS side effects

Question 11

What drug increases the synaptic [dopamine]?

Answer 11

Amantadine

Question 12

What are the dopamine receptor agonists?

Answer 12

Bromocriptine + Pergolide

(ergot alkaloids)

Question 13

Why is pergolide no longer available?

Answer 13

Assoc with valvular heart disease

Question 14

What drug is a D₃ agonist?

Answer 14

Pramipexole

Question 15

What drug is a D₂ agonist?

Answer 15

Ropinirole

Question 16

What drugs are synthetic and sometimes used alone in early stage disease?

Answer 16

Pramipexole + Ropinirole

Question 17

What drug can have an adverse interaction with ropinirole?

Answer 17

Ciprofloxacin

• Can inhibit CYP1A2 (metabolizes ropinirole)
• Dec metabolism + inc blood [ropinirole] = inc side effects

Question 18

What drugs are linked to the rare side effect of compulsive gambling?

Answer 18

Pramipexole + Ropinirole

Question 19

What are pramipexole + ropinirole also Rx for?

Answer 19

Restless leg syndrome

Question 20

What drug is used for rescue of akinesia in “off” periods (when pt is unable to move)?

Answer 20

Apomorphine

Question 21

How is Apomorphine delivered?

Answer 21

Subcutaneously, fast action

Question 22

What should you pretreat Apomorphine with to prevent nausea?

Answer 22

trimethobenzamide

Question 23

What is the function of Selegiline the MAO-B inhibitor?

Answer 23

• Dec “on-off” fluctuations
• Prolong usefullness of levodopa (# of yrs overwhich DOPA will be effective)

Question 24

What is a newer MAO-B inhibitor?

Answer 24

Rasagiline

Question 25

What are the COMT Inhibitors?

Answer 25

Entacapone + Tolcapone

Question 26

What is the MOA of COMT inhibitors, Entacapone, Tolcapone?

Answer 26

• Inhibit peripheral metab of levodopa to 3-O-methyldopa (inhibits uptake of levodopa)
• Enhance uptake of levodopa

Question 27

What are the anticholinergic drugs used to tx Parkinsonism?

Answer 27

Benztropine + Trihexyphenidyl

Question 28

What are the potential drug interactions with anti-parkinson drugs?

Answer 28

• MAOI
• Catecholamines
• Anti-muscarinics