IC17 Flashcards
What is levodopa usually combined with
inhibitor of DOPA decarboxylase;
benserazide/ carbidopa
Does dopamine cross BBB?
No
Does levodopa cross BBB?
No
Purpose of DCI
Prevent peripheral conversion of levodopa to dopamine, thereby reducing side effects
How long does dyskinesia develop aft starting levodopa tx?
3-5 yrs later
Examples of non-ergot dopamine agonist
Ropinirole & Pramipexole
Which MAO-B inhibitor is hepatically metabolised into amphetamines?
Selegiline
Examples of MAO-B inhibitors
Selegiline, rasagiline
COMT stands for
Catechol-O-Methyl Transferase
One of the chemicals a/w neurotoxicity is____
glutamate
How does glutamate act on NMDA receptor
glutamate binds & activate NMDA receptor, activating processes that encourage cell death
Anti-emetic of choice in PD
Domperidone
Example of anticholinergic
trihexyphenidyl
Dose of levodopa needed to saturate DOPA-carboxylase
75-100mg daily
Levodopa: adverse effects
- N/V, orthostatic hypotension
- drowsiness, sudden onset of sleepiness
- hallucination, psychosis
- dyskinesia
Levodopa: DDI
- pyridoxine
- iron
- protein
- dopamine antagonist e.g. metoclopramide, typical antipsychotics, risperidone
Example of non-ergot dopamine agonist
ropinirole, pramipexole
Ropinirole: metabolism
mainly metabolised by liver, to inactive metabolite
Pramipexole: metabolism
excreted largely unchanged in urine
Adverse effects for non-ergot dopamine agonist
Peripheral
- N/V, orthostatic hypotension
- leg edema
Central
- hallucination
- drowsiness, daytime sleepiness
- compulsive behaviour
Adverse effects for ergot dopamine agonist
- valvular heart disease
- fibrosis
Medications that need 2nd dose in afternoon
- MAO-B inhibitor (selegiline)
- Amantadine
Amantadine: adverse effects
- hallucination, insomnia
- confusion
- nausea
- light-headedness
- livedo reticularis
