Parkinsons Pharm Flashcards
What are 3 chemical toxins involved in the development of Parkinsons
Heavy metal poisoning
Anticholinesterase
MPTP
What is the problem with taking L-DOPA alone?
peripheral side fx: fast, irregular, pounding heart beat Constipation, ab pain N/V urinary hesitancy dilated pupils postural hypotension
How do you solve the problem of peripherally active L-DOPA? (2 ways)
administer L-DOPA with CARBIDOPA and ENTECAPONE
–carbidopa is a peripherally acting L-amnio acid decarboxylase inhibitor
–entecapone - peripheral COMT inhibitor
= (prevents peripheral conversion into dopamine)
= More dopamine in the CNS
What is the On-Off phenomenon of parkinson’s? what are Sx of this?
The beneficial time period that L-dopa is effective is shortened
= increase sensitivity to dyskinesia
Dyskinesia =
1. Athetosis - slow involuntary, writhing movements
2. Chorea - quick movements of feet/hands
What are Pramipexole, Ropinirole, Apomorphine?
Dopamine Receptor Agonists
what are some Dopamine Receptor Agonists? What 2 situiations are they useful?
Pramipexole, Ropinirole, Apomorphine
Uses:
- Early in mild Parkinsons
- Later in disease in pts w on-off phenomenon on L-DOPA
What are contraindications of Dopamine Agonists?
history of psychosis
recent myocardial infarction
How do you protect against MPTP toxicity?
MAO-B inhibitors (Selegiline)
What is Selegiline?`
MAO-B inhibitor - used to prevent MPTP toxicity
-minimize on-off fx when used with L-DOPA/carbidopa
What are drug interactions of Selegiline
may cause pt to fail a drug test
- inhibited by oral contraceptives
what is Entacapone?
peripheral COMT inhibitor - increases Dopamine in the CNS
How is Amantadine used in Parkinson’s?
inhibition of neuronal dopamine reuptake
What is the use of Trihexyphenidyl and Benztropine in Parkinsons?
Anticholinergics - reduce trmoe and rigidity in patients on L-DOPA therapy
