AGENTS, CONTROLLING THE FUNCTIONS OF THE CENTRAL NERVOUS SYSTEM - Antiparkinsonian agents Flashcards
Which neurons are involved in parkinsonism?
- Cholinergic neurons
- GABAergic neurons
- Dopaminergic neurons
The pathophysiologic basis for antiparkinsonism therapy is
A selective loss of dopaminergic neurons
Which neurotransmitters is involved in Parkinson′s disease?
- Acetylcholine
- Glutamate
- Dopamine
True or False. The concentration of dopamine in the basal ganglia of the brain is reduced in parkinsonism.
TRUE
Principal aim for treatment of Parkinsonian disorders is
- To restore the normal balance of cholinergic and dopaminergic influences on the basal ganglia with antimuscarinic drugs
- To restore dopaminergic activity with levodopa and dopamine agonists
- To decrease glutamatergic activity with glutamate antagonists
Indicate the drug that induces parkinsonian syndromes
Chlorpromazine
Which drugs is used in the treatment of Parkinsonian disorders
Selegiline
Select the agent, which is preferred in the treatment of the drug-induced form of parkinsonism
Benztropine
Which agents is the precursor of dopamine?
Levodopa
The main reason for giving levodopa, the precursor of dopamine, instead of dopamine is
Dopamine does not cross the blood-brain barrier
Indicate a peripheral dopa decarboxylase inhibitor
Carbidopa
The mechanism of carbidopa′s action is
Inhibition of dopa decarboxilase
True or False. Carbidopa is unable to penetrate the blood-brain barrier, it acts to reduce the peripheral conversion of levodopa to dopamine.
TRUE
When carbidopa and levodopa are given concomitantly
- Levodopa blood levels are increased, and drug half-life is lengthened
- The dose of levodopa can be significantly reduced (by 75%), also reducing toxic side effects
- A shorter latency period precedes the occurrence of beneficial effects
Which preparations combines carbidopa and levodopa in a fixed proportion?
Sinemet
Which statements is correct for levodopa?
- Tolerance to both beneficial and adverse effects develops gradually
- Levodopa is most effective in the first 2-5 years of treatment
- After 5 years of therapy, patients have dose-related dyskinesias, inadequate response or toxicity
Gastrointestinal irritation, cardiovascular effects, including tachycardia, arrhythmias, and orthostatic hypotension, mental disturbances, and withdrawal are possible adverse effects of
Levodopa
Which agents is the most helpful in counteracting the behavioral complications of levodopa?
Clozapine
Which vitamins reduces the beneficial effects of levodopa by enhancing its extracerebral metabolism?
Pyridoxine
Which drugs antagonizes the effects of levodopa because it leads to a junctional blockade of dopamine action?
- Reserpine
- Haloperidol
- Chlorpromazine
Levodopa should not be given to patients taking
Monoamine oxydase A inhibitors
Indicate D2 receptor agonist with antiparkinsonian activity
Bromocriptine
Which antiparkinsonian drugs has also been used to treat hyperprolactinemia?
Bromocriptine
Indicate a selective inhibitor of monoamine oxidase B
Selegiline
True or False. MAO-A metabolizes norepinephrine and serotonin; MAO-B metabolizes dopamine
TRUE
True or False. Treatment with selegilin postpones the need for levodopa for 3-9 months and may retard the progression of Parkinson′s disease.
TRUE
The main reason for avoiding the combined administration of levodopa and an inhibitor of both forms of monoamine oxidase is
Hypertensive emergency
Indicate selective catechol-O-methyltransferase inhibitor, which prolongs the action of levodopa by diminishing its peripheral metabolism
Tolcapone
Which antiparkinsonian drugs is an antiviral agent used in the prophylaxis of influenza A2?
Amantadine
The mechanism of amantadine action is
Stimulating the glutamatergic neurotransmission
Which antiparkinsonism drugs is an anticholinergic agent?
Trihexyphenidyl
Mental confusion and hallucinations, peripheral atropine like toxicity (e.g. Cycloplegia, tachycardia, urinary retention, and constipation) are possible adverse effects of
Benztropine
Indicate the antiparkinsonism drug which should be avoided in patients with glaucoma
Trihexyphenidyl
