Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
20 Cards in this Set
- Front
- Back
|
Dopamine: structure and effect on pharmacokinetics.
|
Relatively polar
Does not cross the BBB |
|
|
L-DOPA: what is it? pharmacokinetics?
|
Neutral AA that is the immediate precursor of dopamine
Crosses the BBB via a saturable, active transport mechanism |
|
|
What happens when you take L-DOPA by itself?
|
Frequent adverse effects due to peripheral conversion of L-DOPA to dopamine. Dopaminergic stimulation of the area postrema leads to nausea and vomiting.
|
|
|
What must be given with L-DOPA to prevent side effects and what does this result in?
|
Carbidopa, an AA decarboxylase inhibitor.
Reduces peripheral production of dopamine. Metabolite is 3-O-methyldopa that provides no benefit and may complete with L-DOPA for active transport into the blodstream and across the BBB. |
|
|
How do pharmacokinetics of L-DOPA change as the disease progresses?
|
Duration of response shortens
Therapeutic window narrows - more susceptible to L-DOPA induced motor fluctuations. |
|
|
Carbidopa: BBB? MOA?
|
Doesn't cross the BBB
Selective reversible inhibitor of AADC (which converts L-DOPA to dopamine) |
|
|
What antiemetic is used with L-DOPA?
|
Domperidone
|
|
|
Domperidone: MOA?
|
Dopamine antagonist that does not cross the BBB
|
|
|
Why don't conventional antiemetics not work in Parkinson's?
|
Work to block central dopamine
|
|
|
List 3 dopamine agonists. Disadvantages?
|
Ropinirole
Pramipexole Apomorphine More expensive Less favorable adverse effects |
|
|
Anticholinergics: MOA? advantages? disadvantages?
|
Restore the dopamine/acetylcholine balance
Inexpensive, helpful for tremor Limited by dose dependent anticholinergic adverse effects (dry eyes, dry mouth, etc.) |
|
|
MAO type B inhibitors: name 1. MOA?
|
Selegiline
Blocks one of the central pathways of dopamine metabolism |
|
|
COMT inhibitors: name 2. MOA?
|
Tolcapone
Entacapone Block metabolism of L-DOPA to 3-O-methyldopa |
|
|
What are 3 strategies to decreased L-DOPA induced chorea?
|
Amantadine
Decreased protein in diet More continuous dopaminergic stimulation |
|
|
Amantadine: MOA? effect?
|
Unknown - may act as mild direct dopamine agonist
Mild symptomatic benefit |
|
|
Why might decreasing protein in diet help?
|
Neutral AAs may compete with L-DOPA for absorption and transport across the BBB
|
|
|
List the dopaminergic adverse effects.
|
Nausea
Orthostatic hypotension Nightmares/hallucinations Suppression of lactation Sleep attacks Impulse control disorder |
|
|
List the non-motor symptoms of Parkinson's disease.
|
Cognitive difficulty
Depression Constipation Sexual dysfunction Sleep disorders |
|
|
What syndrome can result from abrupt cessation of dopaminergic medications in patients with Parkinson's disease?
|
Neuroleptic Malignant-like Syndrome
|
|
|
Neuroleptic malignant-like syndrome: symptoms? treatment?
|
Rigidity, fever, myoglobinuria
Restart medication Supportive care |
