Antiparkinson's

Question 1

Selegiline

Answer 1

• MAO-B inhibitor
• Prevents enzyme from degrading or removing dopamine, is believed to help delay nigral brain cell degeneration.
• Side effects: loss of appetite, nausea, vomiting, diarrhoea, nightmare, palpitation, hallucination

Question 2

Amantadine

Answer 2

• Antiviral agent
• helps treat dyskinesia in PD patients
• side effect: livedo reticularis
• MOA:
  » inhibit reuptake of catecholamine
  » dopamine agonist
  » glutamate NMDA receptor antagonist
• used as systemic monotherapy or adjunct to levodopa.

Question 3

Pergolide

Answer 3

• is a dopamine agonist
• replenishes levels of dopamine in the body
• prevents onset and delays motor complications
• can cause restrictive valvular disease
• dopamine agonists are used in the early stages to treat PD
• other side effects include:
  » similar to levodopa
  » ergot - fibrosis
  » pedal edema
  » arrythymias

Question 4

Ropinirole

Answer 4

• is a dopamine agonist

- can cause somnolence

Question 5

Levodopa

Answer 5

• gold standard for treating PD
• dopamine precursor, “2-in-1” with peripheral decarboxylase inhibitors (benserazide + levodopa –> madopar)
• Short-term side effects: nausea, insomnia, postural hypotension
• Long-term side effects: motor fluctuations, dyskinesia
• must always be titrated to the lowest dose, no matter which stage of PD the patient is in to ensure good motor function.
• Available as normal and long-acting drug

Question 6

Entacapone

Answer 6

• COM-T inhibitor
• can be used only as adjunct to levodopa, to prevent an enzyme from converting levodopa to its inactive form
• Side effects:
  » dyskinesia
  » urinary discoloration
  » visual hallucination
  » nausea, diarrhoea
  » daytime drowsiness, sleep disturbance

Question 7

Bromocriptine

Answer 7

• dopamine agonist

Question 8

Trihexyphenidyl

Answer 8

• Artane (2-15mg/day)
• Anticholinergic agent
• Usefull in treating tremors, peripherally acting agents may help in controlling sialorrhea
• Anticholinergic side effects include: dry mouth, sedation, blurred vision, hallucinations, delirium, constipation
• Anticholinergics can be used as symptomatic monotherapy or adjunct to levodopa to treat PD.