Question 1

Catechol-O-methyltransferase (COMT)inhibitors such as entacapone (Comtan)and tolcapone (Tasmar)may enhance the effects of levodopa because these drugs&#10;A) decrease the breakdown of dopamine in the brain&#10;B) increase dopamine absorption from the GI tract&#10;C) prevent conversion of levodopa to an inactive metabolite in the bloodstream&#10;D) increase the breakdown of dopamine in the brain&#10;E) prolong the activity of acetylcholine in the brain

Accepted Answer

COMT inhibitors prevent the conversion of levodopa to an inactive metabolite in the bloodstream, thereby enhancing the availability and effectiveness of levodopa.

Question 2

All of the following drugs can be used to treat Parkinson disease EXCEPT&#10;A) L-DOPA&#10;B) dopamine antagonists&#10;C) catechol-o-methyltransferase (COMT) inhibitors&#10;D) anticholinergic drugs&#10;E) MAO type b inhibitors (e.g., selegiline)

Accepted Answer

Dopamine antagonists actually worsen symptoms of Parkinson's disease by blocking dopamine receptors, whereas the other options listed are all commonly used to treat Parkinson's disease.

Question 3

With regard to levodopa administration,&#34;end-of-dose akinesia&#34; describes the phenomenon where&#10;A) a patient experiences hallucinations and other psychotropic effects of levodopa&#10;B) drug effects follow an on-off pattern throughout the day&#10;C) levodopa seems to become less effective when it is administered for prolonged periods (3 to 4 years)&#10;D) the effectiveness of levodopa seems to wear off prior to the next dose&#10;E) none of the above are true

Accepted Answer

End-of-dose akinesia refers to a phenomenon where the effectiveness of levodopa seems to wear off before the next dose is due. This occurs towards the end of the dosing cycle and is a common problem in patients with Parkinson's disease who are being treated with levodopa.

Question 4

All of the following characteristics of dopamine agonists are true EXCEPT&#10;A) dopamine agonists cross the blood brain barrier&#10;B) all clinically useful dopamine agonists must be given by parenteral (nonoral) routes&#10;C) the half-life of a dopamine agonist is typically longer than the half-life of levodopa&#10;D) dopamine agonists tend to have a lower risk of dyskinesias and other motor side effects compared to levodopa&#10;E) some dopamine agonists can be administered transdermally by a patch

Accepted Answer

Option B is untrue because there are clinically useful dopamine agonists that can be given orally, such as pramipexole and ropinirole. Therefore, not all dopamine agonists must be given by parenteral routes. The rest of the options are true: dopamine agonists cross the blood brain barrier, their half-life is generally longer than levodopa, they have a lower risk of dyskinesias and other motor side effects compared to levodopa, and some dopamine agonists can be administered transdermally by a patch.

Question 5

Upon entering the brain,levodopa is then transformed into dopamine the enzyme&#10;A) dopa transmutase&#10;B) dopa decarboxylase&#10;C) monoamine oxidase&#10;D) acetylcholinesterase&#10;E) sodium-potassium ATPase

Accepted Answer

Levodopa is transformed into dopamine via the enzyme dopa decarboxylase.

Question 6

Drugs such as selegiline (Eldepryl)and rasagiline (Azilect)that inhibit the monoamine oxidase type B (MAOB)enzyme may be helpful in Parkinson disease because&#10;A) they increase dopamine absorption from the GI tract&#10;B) they increase the conversion of levodopa to dopamine in the bloodstream&#10;C) they decrease the movement of levodopa across the blood-brain barrier&#10;D) they decrease the breakdown of dopamine in the brain&#10;E) they increase the breakdown of acetylcholine in the brain

Accepted Answer

MAOB is responsible for the breakdown of dopamine in the brain. Therefore, inhibiting this enzyme with drugs such as selegiline and rasagiline can increase dopamine levels in the brain and improve Parkinson's symptoms. They do not affect dopamine absorption from the GI tract, the conversion of levodopa to dopamine in the bloodstream, or the movement of levodopa across the blood-brain barrier. They also do not affect the breakdown of acetylcholine in the brain.

Question 7

Neuronal death that occurs in Parkinson disease may ultimately be caused by the formation of harmful byproducts of oxygen metabolism,better know as&#10;A) free radicals&#10;B) dopamine antagonists&#10;C) cholinesterase inhibitors&#10;D) monoamine oxidase inhibitors&#10;E) decarboxylase inhibitors

Accepted Answer

The harmful byproducts of oxygen metabolism are free radicals, which can cause oxidative stress and damage to neurons in Parkinson disease. This is why antioxidants are being studied as potential treatments for Parkinson disease, as they can help neutralize free radicals and prevent further neuron damage. The other choices, dopamine antagonists, cholinesterase inhibitors, monoamine oxidase inhibitors, and decarboxylase inhibitors, are all types of medications used in the treatment of Parkinson disease, but they do not directly relate to the formation of harmful byproducts of oxygen metabolism.

Question 8

A decrease in dopamine influence in the basal ganglia leads to increased influence of ______ which can be treated to some extent by _______.&#10;A) acetylcholine; anticholinergic drugs&#10;B) norepinephrine; dopamine antagonists&#10;C) acetylcholine; cholinesterase inhibitors&#10;D) norepinephrine; anticholinergic drugs&#10;E) acetylcholine; dopamine antagonists

Accepted Answer

A decrease in dopamine in the basal ganglia leads to an increased influence of acetylcholine. This imbalance can be treated with anticholinergic drugs, which reduce the effects of acetylcholine, helping to restore balance and improve symptoms.

Question 9

Oral administration of dopamine is NOT effective in the treatment of Parkinson disease because dopamine is&#10;A) degraded into L-DOPA in the blood stream&#10;B) digested in the stomach&#10;C) unable to pass from the blood stream into the brain&#10;D) degraded by dopa decarboxylase in the blood stream&#10;E) none of the above

Accepted Answer

Dopamine cannot cross the blood-brain barrier, which prevents it from entering the brain from the bloodstream, making oral administration ineffective for treating Parkinson's disease.

Question 10

To prevent premature conversion of L-dopa to dopamine in the bloodstream,L-dopa is often administered with carbidopa because carbidopa is&#10;A) a dopamine antagonist&#10;B) an anticholinergic drug&#10;C) a cholinesterase inhibitor&#10;D) a peripheral decarboxylase inhibitor&#10;E) an antioxidant

Accepted Answer

Carbidopa is a peripheral decarboxylase inhibitor, which means it prevents the conversion of L-dopa to dopamine in the bloodstream, allowing more L-dopa to reach the brain and be converted to dopamine there. This helps to increase the effectiveness of L-dopa therapy for Parkinson's disease.

Question 11

Parkinson disease typically occurs because of the slow,progressive degeneration of specific _______-secreting neurons in the ______.&#10;A) acetylcholine; cortex&#10;B) norepinephrine; cerebellum&#10;C) dopamine; basal ganglia&#10;D) serotonin; limbic system&#10;E) glutamate; brain stem

Accepted Answer

The answer of Parkinson disease typically occurs because of the...

Question 12

Levodopa administration can help resolve the symptoms of Parkinson disease,but this drug can also cause&#10;A) gastrointestinal problems&#10;B) cardiac arrhythmias&#10;C) postural hypotension&#10;D) dyskinesias&#10;E) all the above are true

Accepted Answer

The answer of Levodopa administration can help resolve the symptoms...

Deck 10: Pharmacologic Management of Parkinson Disease