Posts: 3,675,934
Threads: 734,342
Joined:
Sep 2021
Reputation:
5
16.
What is the "on-off phenomenon" that is associated with levodopa (l-dopa) therapy?
A.
Fluctuation in clinical response independent of drug levels
B.
Improvement of clinical response after a drug holiday
C.
Shortened duration of clinical response per dose
17.
A 29-year-old female has a 10-year history of migraine headaches. She can usually sense onset. Which of the following agents is the drug of choice for countering acute onset of her headaches
A.
Ergotamine
B.
Propranolol
C.
Methysergide
D.
Pseudoephedrine
E.
Aspirin
18.
Which of the following is a highly selective inhibitor of cyclooxygenase II?
A.
Aspirin
B.
Acetaminophen
C.
Ibuprofen
D.
Celecoxib
E.
Piroxicam
19.
A patient with ulcerative colitis is best treated with which of the following agents?
A.
Celecoxib
B.
Naproxen
C.
Sulfasalazine
D.
Infliximab
E.
Penicillamine
20.
A 40-year-old male with a diagnosis of moderate to severe asthma is placed on zileuton. What is the mechanism of action of zileuton?
A.
Inhibition of cytokine production
B.
Inhibition of leukotriene production
C.
Inhibition of mediator release
D.
Inhibition of muscarinic receptor action
E.
Inhibition of calcium (Ca2+) channel activity
Posts: 3,675,934
Threads: 734,342
Joined:
Sep 2021
Reputation:
5
16 a
20 b
19 c
17 a or c??
Posts: 3,675,934
Threads: 734,342
Joined:
Sep 2021
Reputation:
5
16--a
17--a
18--d
19--c
20--b
Posts: 3,675,934
Threads: 734,342
Joined:
Sep 2021
Reputation:
5
16.
What is the "on-off phenomenon" that is associated with levodopa (l-dopa) therapy?
A.
Fluctuation in clinical response independent of drug levels
B.
Improvement of clinical response after a drug holiday
C.
Shortened duration of clinical response per dose
The answer is: A
Fluctuations in clinical response to L-dopa may or may not be related to drug levels (time of last dose). The likelihood of both kinds of fluctuation increases with longer duration of treatment. When these fluctuations are unrelated to drug levels, they are termed the on-off phenomenon; the mechanism is unclear.
17.
A 29-year-old female has a 10-year history of migraine headaches. She can usually sense onset. Which of the following agents is the drug of choice for countering acute onset of her headaches
A.
Ergotamine
B.
Propranolol
C.
Methysergide
D.
Pseudoephedrine
E.
Aspirin
The answer is: A
Ergotamine has several pharmacologic properties, including the blockade of -adrenergic receptors; however, its mechanism of action in treating migraine headaches is primarily related to its agonistic interaction with serotonin receptors (5-HT1D), resulting in vasoconstriction. Although chronic treatment with this nonsedative, nonanalgesic drug does not decrease the frequency of or prevent migraine attacks, an oral dose of ergotamine is the drug of choice for combating an incipient attack of migraine headache, especially during the prodromal stage.
18.
Which of the following is a highly selective inhibitor of cyclooxygenase II?
A.
Aspirin
B.
Acetaminophen
C.
Ibuprofen
D.
Celecoxib
E.
Piroxicam
The answer is: D
Celocoxib is a cyclooxygenase-II inhibitor. Aspirin, ibuprofen, and piroxicam are relatively nonselective inhibitors of cyclooxygenases. Acetaminophen has no effect on cyclooxygenases.
19.
A patient with ulcerative colitis is best treated with which of the following agents?
A.
Celecoxib
B.
Naproxen
C.
Sulfasalazine
D.
Infliximab
E.
Penicillamine
The answer is: C
Sulfasalazine is a derivative of sulfapyridine and 5-aminosalicylic acid. It is not significantly absorbed following oral administration. The 5-aminosalicyclic acid moiety is released by intestinal bacterial action. Sulfasalazine is more effective in maintaining than causing remission in ulcerative colitis. Celocoxib (a selective cyclooxygenase inhibitor), infliximab (a chimeric monoclonal antibody), and penicillamine (an analogue of cysteine) have a role in the treatment of rheumatoid arthritis. Naproxen, a nonselective cyclooxygenase inhibitor, is indicated for usual rheumatological indications.
20.
A 40-year-old male with a diagnosis of moderate to severe asthma is placed on zileuton. What is the mechanism of action of zileuton?
A.
Inhibition of cytokine production
B.
Inhibition of leukotriene production
C.
Inhibition of mediator release
D.
Inhibition of muscarinic receptor action
E.
Inhibition of calcium (Ca2+) channel activity
The answer is: B
Zileuton is a 5-lipoxygenase inhibitor. Although it is not clear that leukotrienes are partly responsible for the symptoms of asthma, zileuton has a bronchodilator effect that is therapeutically efficacious. The 5-lipoxygenase inhibitors may be less effective than inhaled steroids, but they have the advantage that they are orally administered. This may be an advantage for those individuals who either reject steroid therapy or have difficulty using an inhaler.
