Agents for PD and Dementia

Question 1

[Side Effects] Levodopa

Answer 1

[Dopaminergic effects]
1. N/V
2. Orthostatic hypotension
3. Hallucinations
4. Drowsiness, sudden sleep onset

L-Dopa induced dyskinesia

Question 2

Administration cautions for L-DOPA sustained release forms

Answer 2

Do NOT crush. (Sinemet SR)
Do NOT open capsule. (Madopar HBS)

Question 3

Mgmt of Levodopa - Wearing off

Answer 3

More frequent administration, Sustained release formulation

Question 4

Mgmt of Levodopa-induced Dyskinesia

Answer 4

Agents:
1. MAO-B inhibitors (Selegiline, Rasagiline)
2. Dopamine agonists (Ropinirole, Pramipexole, Rotigotine (TOP), Apomorphine (SQ))
3. COMT inhibitors (Entacapone)

Sustained-release formulation?

Question 5

[Side Effects] Anticholinergics

Answer 5

Dry mouth
Constipation
Nausea

Dilated pupils
Urinary retention

Dry Skin

Question 6

[Side Effects] MAO-Bi (Selegiline)

Answer 6

Dry mouth
Constipation
Nausea

Dilated pupils
Urinary retention

Dry Skin

(!) Orthostatic hypotension
(!) Difficulty sleeping (due to amphetamine metabolite

Question 7

Which of the following interacts with L-DOPA?
1) Iron
2) Calcium
3) Protein
4) Domperidone

Answer 7

Iron and Protein interferes w L-DOPA absorption. Iron should be taken 2 hrs apart.

Domperidone (D2 antagonist) is useful for emesis. Should NOT use Metoclopramide or Prochlorperazine.

Risperidone should also not be used.

Calcium does not interact w L-DOPA, but does with COMTi.

Question 8

Sx of L-DOPA-induced dyskinesia

Answer 8

1. Involuntary, uncontrollable
2. Twitching, jerking
3. Peak dose dyskinesia (uncontrolled shakes, tics, tremors)
4. Dystonia (involuntary muscle contraction)

Question 9

Agents for tremor control

Answer 9

1. Anticholinergics (Benzhexol, Benztropine)
2. NMDA receptor antagonist (Amantadine)

Question 10

[MoA] Amantadine

Answer 10

1. NMDA receptor antagonist
2. Dopamine receptor agonist
3. Enhanced release of stored dopamine

Question 11

[Side Effects] NMDA receptor antagonist

Answer 11

1. Cognitive impairment
2. Hallucination
3. Insomnia
4. Nightmares
5. (!) Livedo Reticularis

Question 12

[Side Effects] Ropinirole (Dopamine agonist)

Answer 12

1. N/V
2. Orthostatic hypotension
3. Hallucinations
4. Somnolence, day-time sleepiness
5. (!) Compulsive behaviours
6. (!) Leg oedema

Ergots: Fibrosis, Valvular Heart Disease

Question 13

Place in mgmt of PD - Dopamine agonists

Answer 13

Monotx in young-onset PD;
Adjunct to L-DOPA;
Mgmt of motor complications caused by L-DOPA

Question 14

Place in mgmt - L-DOPA

Answer 14

Moderate-to-severe Parkinson’s