Parkinsons Stuff Flashcards
(35 cards)
What are some theroies for PD and it’s etiology?
Viral infection, brain injuries, genetic component
What is PD characterized by?
Loss of DA neurons in the substantia niagra
What causes pseudoparkinsoism?
DA receptor antagonists like antipsychotics and antiemetics
Toxins like MPTP
What does MPTP break down into because of MAO-B?
MPP+
What is PD triad symptoms?
Bradykinesia/akinesia- Difficulty initiating movements
Resting tremor
Skeletal muscle rigidity or hypertonicity
Given the pathophys of PD, what two broad therapies are indicated?
Replacement therapy for DA
Decreasing cholinergic transmission
What are the main muscarinic anticholinergic drugs for PD?
Trihexyphenidyl and BENZTROPINE
What are the side effects of anticholinergics?
Drowsiness, mental slowness, tachycardia, dry mouth, constipation
What are contraindications to anticholinergics?
Prostate hyperplasia, obstructive GI disease, angle-closure glaucoma
What is the rate limiting step in the production of dopamine?
Tyrosine to dopa by the enzyme tyrosine hydroxylate
Which crosses the BBB? L-Dopa or dopamine?
L-dopa
Whats the pathway to create dopamine?
Tyrosine, to Dopa, to dopamine
What does dopamine stimulate once in the brain?
Basal ganglia
What are the problems with L-dopa?
Diminished effectiveness after 4-6 years (Wearing off effect, and on-off phenomenon)
Does not stop progression of PD
What are the side effects to L-dopa?
GI disturbances (Avoid dopaminergic antiemetics like prochlorperazine)
Tachycardia, orthostatic hypotension
Dyskinesia- up to 80% patients
Behavioral issues-agitation,delerium, etc
Hormonal-inhibition of the HPA axis and prolactin
What are the drug interactions with L dopa?
Pyridone(Vit B6)
MAOI inhibitors
Antipsychotics- strictly prohibited
High protein diet needed for absorption and transport
Why is carbidopa added with L dopa?
Reduces daily requirement of levodopa by 75% through reduced metabolism in the GI tract
What are the dopamine receptor agonists for PD?
Bromocriptine, ropinirole. pramipexole, and roigotine
What receptor affinity does bromocriptine and ropinirole have?
D2 agonist
What receptor affinity does pramipexole have?
D3 agonist
What is the administration of rotigotine?
Patch
What is the contraindications for DA in PD?
Psychotic illness history, recent MI, or GI ulcers
What is the age DA agonist are no longer recommended?
60
What are side effects of DA agonists?
GI issues
CV problems- orthostatic hypotension, arrhythmias
Dyskinesia
Mental disturbances
