Parkinson's Disease Flashcards
1
Q
Levodopa
A
- Levodopa is used as a shuttle to transport precursor to dopamine across the BBB.
- The precursors are converted to dopamine, which is stored in the surviving nigrostratial nerve terminals.
- It is administered with carbidopa or benzerazide to block peripheral conversion of levodopa to dopamine.
- Adverse effects include nausea, vomiting, postural hypotension, involuntary movements, restlessness and cardiac arrhythmias.
2
Q
Carbidopa
A
- Administered with levodopa to block peripheral conversion of levodopa to dopamine.
- Metabolism of L-Dopa in GI tract and peripheral tissues is decreased, therefor increasing L-Dopa levels in CNS.
- Carbidopa is highly emetogenic as it stimulates the CTZ.
- Side effects include nausea, abdo pain, constipation, orthostatic hypotension, dizziness, sedation, confusion, and hallucination.
3
Q
Benzerazide
A
- Blocks peripheral conversion of levodopa to dopamine. Combined with levodopa.
4
Q
Pramipexole or Bromocriptine
A
- Dopamine agonist.
- Used to delay the onset of L-Dopa therapy and prolong the effective treatment period in patients with deteriorating response.
- Also can be given to those who cannot tolerate L-Dopa.
- Crosses the BBB.
- Potential side effects include somnolence, dyskinesia, nausea, vomiting, orthostatic hypotension, nightmares, hallucination, confusion and dizziness.
5
Q
What is the difference between pramipexole and bromocriptine?
A
- Bromocriptine is an ergot, so it also targets serotonin receptors.
- Pramipexole is a non-ergot so it does not target serotonin receptors.
6
Q
Entacapone
A
- COMT inhibitor.
- Inhibits degradation of dopamine.
- Increases the duration of effect of levodopa dose. Can increase peak levels of levodopa, and should be taken with carbidopa/levodopa.
- Can reduce the required dosage of levodopa/carbidopa.
7
Q
Selegiline
A
- Selective MAOI (MAO-B).
- Reduces degradation of synaptic dopamine and prolonged dopaminergic activity.
- When used as a mono therapy delays the need for L-Dopa by an average of nine months.
- Possible side effects includes nausea, dizziness, abdominal pain, confusion, and exacerbation of L-dopa side effects.
8
Q
Benztropine
A
- Anticholinergic.
- Used in patients to reduce the side effects of antipsychotic medications. Antipsychotic medications can lead to pseudo-parkinsonism and dystonia.
- Also a second line drug for the treatment of Parkinson’s. Improves tremor but not rigidity or bradykinesia.
9
Q
Amantadine
A
- Inhibits dopamine reuptake and blocks ACh and glutamate receptors.
- Currently being used to reduce involuntary spasmodic twitching movements. Was used as an anti-viral, now used as an antiparkinsonian drug.
- Effect on Parkinson’s not understood.
- Amantadine is cautioned in renal failure patients and has a narrow TI.
- Side effects include nausea, dizziness, confusion, hallucinations, nightmares, dry mouth, peripheral oedema and livedo reticularis.
10
Q
What is Parkinson’s disease?
A
- Parkinson’s is a degenerative brain disorder affecting movement, and it is characterized by EPSE symptoms.
- The cause is a deficiency of dopamine, but how this happens is unknown. It is a progressive and incurable disease, and severely affects quality of life.
11
Q
What are the major symptoms of Parkinson’s Disease?
A
TRAP - Tremor - Rigidity - Akinesia and bradykinesia - Postural instability and gait instability (shuffling feet).
12
Q
What are the non-motor related conditions associated with PD?
A
- Depression and Anxiety
- Cognitive disorders such as dementia
- Sleep abnormalities
- Autonomic dysfunction e.g. constipation
- Sensory e.g. olfactory dysfunction
- Fatigue and weight loss