AGENTS, CONTROLLING THE FUNCTIONS OF THE CENTRAL NERVOUS SYSTEM - Antiparkinsonian agents

Question 1

Which neurons are involved in parkinsonism?

Answer 1

• Cholinergic neurons
• GABAergic neurons
• Dopaminergic neurons

Question 2

The pathophysiologic basis for antiparkinsonism therapy is

Answer 2

A selective loss of dopaminergic neurons

Question 3

Which neurotransmitters is involved in Parkinson′s disease?

Answer 3

• Acetylcholine
• Glutamate
• Dopamine

Question 4

True or False. The concentration of dopamine in the basal ganglia of the brain is reduced in parkinsonism.

Answer 4

TRUE

Question 5

Principal aim for treatment of Parkinsonian disorders is

Answer 5

• 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

Question 6

Indicate the drug that induces parkinsonian syndromes

Answer 6

Chlorpromazine

Question 7

Which drugs is used in the treatment of Parkinsonian disorders

Answer 7

Selegiline

Question 8

Select the agent, which is preferred in the treatment of the drug-induced form of parkinsonism

Answer 8

Benztropine

Question 9

Which agents is the precursor of dopamine?

Answer 9

Levodopa

Question 10

The main reason for giving levodopa, the precursor of dopamine, instead of dopamine is

Answer 10

Dopamine does not cross the blood-brain barrier

Question 11

Indicate a peripheral dopa decarboxylase inhibitor

Answer 11

Carbidopa

Question 12

The mechanism of carbidopa′s action is

Answer 12

Inhibition of dopa decarboxilase

Question 13

True or False. Carbidopa is unable to penetrate the blood-brain barrier, it acts to reduce the peripheral conversion of levodopa to dopamine.

Answer 13

TRUE

Question 14

When carbidopa and levodopa are given concomitantly

Answer 14

• 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

Question 15

Which preparations combines carbidopa and levodopa in a fixed proportion?

Answer 15

Sinemet

Question 16

Which statements is correct for levodopa?

Answer 16

• 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

Question 17

Gastrointestinal irritation, cardiovascular effects, including tachycardia, arrhythmias, and orthostatic hypotension, mental disturbances, and withdrawal are possible adverse effects of

Answer 17

Levodopa

Question 18

Which agents is the most helpful in counteracting the behavioral complications of levodopa?

Answer 18

Clozapine

Question 19

Which vitamins reduces the beneficial effects of levodopa by enhancing its extracerebral metabolism?

Answer 19

Pyridoxine

Question 20

Which drugs antagonizes the effects of levodopa because it leads to a junctional blockade of dopamine action?

Answer 20

• Reserpine
• Haloperidol
• Chlorpromazine

Question 21

Levodopa should not be given to patients taking

Answer 21

Monoamine oxydase A inhibitors

Question 22

Indicate D2 receptor agonist with antiparkinsonian activity

Answer 22

Bromocriptine

Question 23

Which antiparkinsonian drugs has also been used to treat hyperprolactinemia?

Answer 23

Bromocriptine

Question 24

Indicate a selective inhibitor of monoamine oxidase B

Answer 24

Selegiline

Question 25

True or False. MAO-A metabolizes norepinephrine and serotonin; MAO-B metabolizes dopamine

Answer 25

TRUE

Question 26

True or False. Treatment with selegilin postpones the need for levodopa for 3-9 months and may retard the progression of Parkinson′s disease.

Answer 26

TRUE

Question 27

The main reason for avoiding the combined administration of levodopa and an inhibitor of both forms of monoamine oxidase is

Answer 27

Hypertensive emergency

Question 28

Indicate selective catechol-O-methyltransferase inhibitor, which prolongs the action of levodopa by diminishing its peripheral metabolism

Answer 28

Tolcapone

Question 29

Which antiparkinsonian drugs is an antiviral agent used in the prophylaxis of influenza A2?

Answer 29

Amantadine

Question 30

The mechanism of amantadine action is

Answer 30

Stimulating the glutamatergic neurotransmission

Question 31

Which antiparkinsonism drugs is an anticholinergic agent?

Answer 31

Trihexyphenidyl

Question 32

Mental confusion and hallucinations, peripheral atropine like toxicity (e.g. Cycloplegia, tachycardia, urinary retention, and constipation) are possible adverse effects of

Answer 32

Benztropine

Question 33

Indicate the antiparkinsonism drug which should be avoided in patients with glaucoma

Answer 33

Trihexyphenidyl