movement disorders pharm Flashcards
(18 cards)
what is the main adverse effect of L-dopa? how should it be managed? what is another main adverse effect?
GI: N/V, anorexia->avoid antiemetics
CV: arrhythmias, orthostatic hypotension
what is an added adverse effect of carbidopa? what is associated with long-term use of L-dopa/carbidopa?
behavioral changes
dyskinesias
what shouldn’t be given with L-dopa?
pharmacologic doses of B6: increases dopa metabolism
MAO-A inhibitors: HTN crisis
when shouldn’t L-dopa be given?
during or after meal
glaucoma, psychotic patients, cardiac disease
what are the selectivities of the dopamine agonists?
apomorphine: D1/2
bromocriptine: D2, partial D1
pramipexole: D2
ropinirole: D2
when is apomorphine primarily used?
rescue drug for disabling on-off phenomenon
which dopamine agonist also acts as free radical scavenger? which is metabolized by CYP1A2?
pramipexole
ropinirole
what adverse effects do dopamine agonists have in addition to those of L-dopa?
- impulse control disorders (D2-selective agents)
2. hallucinations, confusions, delusions
what does an overdose of amantadine cause? when is it contraindicated?
psychosis
history of seizures or heart failure
what are two reasons MAO-B inhibitors are useful in Parkinson’s?
prevent breakdown of dopamine/reduce on-off
reduce free radical production by MAO-B
what 3 drugs are contraindicated with MAO-B inhibitors?
meperidine, TCA’s, SSRI’s
what are the two MAO-B inhibitors and which is preferred?
selegiline: little effect used alone
rasagiline: preferred, more potent
what drug has amphetamine/metamphetamine as metabolites?
selegiline
what are two reasons COMT inhibitors are useful in PD?
prevent breakdown of L-dopa/reduce on-off
reduce 30MD production (competes with L-dopa for absorption/crossing BBB)
what are the two COMT inhibitors? which is preferred?
entacapone: preferred, only peripheral actions
tolcapone: hepatotoxicity, central and peripheral
what three antimuscarinics are used in PD and why?
benztropine, diphenhydramine, trihexyphenidyl
block cholinergic activity in striatum that opposes dopaminergic activity
how do reserpine and tetrabenazine work? which is preferred?
central dopamine-depleting agents used to treat chorea of HD
tetrabenazine has less troublesome adverse effects
how do chlorpromazine and haloperidol work?
D2-antagonists used for chorea in HD
block inhibition of indirect pathway so more inhibition of motor thalamus
