Parkinson Quiz Flashcards
Dopamine does not cross the BBB and if given into the peripheral circulation has no therapeutic effect in parkinsonism. However, Levodopa, the immediate metabolic precursor of dopamine, does enter the brain, where it is decarboxylated to dopamine. Which response is correct?
A) Levodopa is an opiate/hypnotic
B) Levodopa is a serotonin antagonist
C) Carbidopa, a peripheral dopa decarboxylase inhibitor, reduces peripheral conversion of levodopa to dopamine but does not interfere with central decarboxylation of levodopa.
D) Levodopa is an anticholinergic
C
Match the medication with its principle MOA
Selegiline
Pramiprexole
Levodopa
Cabergoline
Dopamine agonist
Dopamine precursor
MAO inhibitor/antagonist
Selegiline – MAO inhibitor
Pramiprexole – dopamine agonist
Levodopa – dopamine precursor
Cabergoline – dopamine agonist
Match:
Pramiprexole
Rasagiline
Cowage
Supplement that contains levodopa
Mechanistic neuroprotective effect is possible due to its ability to scavenge hydrogen peroxide
A clinical trial found neuroprotective effects in the low dose arm, but the high dose arm failed to demonstrate protective action
Pramiprexole – mechanistic neuroprotective effect is possible due to its ability to scavenge hydrogen peroxide
Rasagiline - a clinical trial found neuroprotective effects in the low dose arm, but the high dose arm failed to demonstrate protective action
Cowage – a supplement that contains levodopa
Which statement concerning the drugs used in parkinsonism is accurate?
A) Dopamine receptor agonists should never be used in Parkinson’s disease before a trial of levodopa
B) Selegiline is a selective inhibitor of COMT
C) Levodopa causes mydriasis and may precipitate an acute attack of glaucoma
D) The primary benefit of antimuscarinic drugs in parkinsonism is their ability to relieve bradykinesia
E) Therapeutic effects of amantadine continue for several years
C – the non-ergot dopamine agonists (pramiprexole, ropinirole) are commonly used prior to levodopa in mild parkinsonism. The mydriatic action of levodopa may increase intraocular pressure; drug should be used cautiously in patients with open angle glaucoma and is contraindicated in those with angle-closure glaucoma. Antimuscarinic drugs may improve the tremor and rigidity of parkinsonism but have little effect on bradykinesia. Selegiline is a selective inhibitor of MAO type B. amantadine is effective for only a few weeks.
Which of the following medications is most suitable for management of essential tremor in a patient who has pulmonary disease?
A) Diazepam
B) Levodopa
C) Propranolol
D) Metoprolol
E) Albuterol
D – increased activation of beta adrenergic receptors is implicated in essential tremor, and management commonly involves administration of a beta adrenergic antagonist. The more selective B1 blocker, metoprolol, is equally effective as propranolol and is a better option for a patient with pulmonary disease because it does not block pulmonary adrenoreceptors.
Management of Off Episodes. Identify the statement that is not correct.
A) Increase the frequency of carbidopa/levodopa
B) Add a dopamine agonist
C) Use an extended release version of carbidopa/levodopa
D) Levodopa inhalation powder is proven superior to the above options
D – levodopa inhalation powder was only compared to placebo. Reserve this highly irritating and costly option for patients who do not respond to the addition of other dopamine enhancing medications, or to extended release carbidopa/levodopa.
Which statement is correct?
Levodopa:
A) Causes fewer CNS adverse effects when combined with carbidopa
B) Fluctuates in effectiveness over time
C) Prevents extrapyramidal effects of antipsychotic medications
D) Pulmonary toxicity is the major concern
B – carbidopa/levodopa causes less peripheral toxicity than levodopa alone. There is more CNS toxicity due to greater availability of levodopa in the CNS. This medication is NOT effective for antagonizing the effects of dopamine antagonists such as antipsychotic medications.
Apomorphine is used for temporary relief of “off periods” of akinesia in parkinsonian patients managed with optimal dopaminergic therapy. Three days of pretretment with trimethobenzomide are necessary before initiation of apomorphine.
Which statement about apomorphine is correct?
A) It is a highly potent and rapid acting dopamine agonist
B) Is a morphine antagonist
C) Is taken orally
D) Is a serotonin agonist
A
A 70 y/o M with advanced PD asks your opinion about deep brain stimulation (DBS). He has been taking carbidopa/levodopa plus selegiline for more than a decase. His dyskinesia is intolerable. Your advice about DBS treatment:
A) DBS treated patients continuing medication have less dyskinesia
B) DBS treated patients can have marked improvement in off medication motor function
C) Speech, freezing of gait, and cognition may worsen following DBS
D) All are correct
D
