Antiparkinsons drugs Flashcards
what is the intracytoplasmic aggregate in parkinsons disease?
alpha synuclein
PD is characterized by loss of what NT? where? what is the result?
dopamine
substantia nigra, projecting to striatum
increased activity of cholinergic pathways (Ach)
what are the cardinal signs and symptoms of PD?
bradykinesia
muscular rigidity
resting tremor
postural instability
what is the result of SN pars compacta degeneration in PD? what is the net effect?
overactivity of indirect pathway from striatum to pallidum
neurons in SN pars reticulata and globus pallidus (internal) become more active
increased inhibition of VA/VL thalamus
reduced excitatory input to cortex
diminished execution of motor movement
what are the treatment strategies for PD?
DA replacement DA receptor agonists L-DOPA degradation inhibitors increase in DA release anticholinergic agents
what is the most common drug used to treat PD? which symptoms does is primarily improve?
L-DOPA
bradykinesia and rigidity
what is carbidopa?
inhibitor of dopa decarboxylase in the periphery
what does carbidopa do?
inhibits premature breakdown of levodopa in periphery
what are the adverse effects of levodopa?
dyskinesias response fluctuations GI disturbance - nausea, vomiting CV - postural hypotension, tachycardia behavioral
what are the drug interactions with levodopa?
pyridoxine (vitamin B6) MAOIs antipsychotics protein rich meals anticholingergics
what are the DA receptor agonist agents?
pramipexole
ropinirole
apomorphine
what is the MOA of the DA receptor agonists?
agonists at D2 receptors
what are the adverse effects of DA receptor agonists?
GI, CV, dyskinesias, behavioral, headache, impulse control
what are the MAO-B inhibitor L-DOPA degradation blockers?
rasagiline
selegiline
what is the MOA of the L-DOPA degradation blockers?
inhibits MAO-B selectively at lower doses and decreases breakdown of DA
