NSG533 / NSG 533 Exam Complete Review
Questions and Verified Answers | 100% Correct |
Grade A | over 80+ quiz with advanced
rationales download now
Question:
What is the mechanism of action of Histamine-2 Receptor Antagonists (H2RAs) such as
cimetidine, famotidine, nizatidine, and ranitidine?
Options:
A. Stimulate gastric acid secretion
B. Block histamine receptors in gastric parietal cells
C. Inhibit H+/K+-ATPase in parietal cells
D. Neutralize gastric acid directly
Answer:
B. Block histamine receptors in gastric parietal cells
Rationale:
H2RAs decrease acid secretion by blocking H2 receptors on gastric parietal cells. They
provide relief from acute GERD symptoms and can be used prophylactically. While more
effective than antacids for chronic GERD, they are less potent than PPIs. Famotidine is
considered the most effective in the class for acid suppression and ulcer healing.
Question:
Which statement correctly describes the action of Proton Pump Inhibitors (PPIs) like
omeprazole, pantoprazole, and lansoprazole?
Options:
A. Neutralize gastric acid immediately
B. Block histamine receptors in parietal cells
C. Inhibit H+/K+-ATPase in parietal cells
D. Stimulate gastric emptying
Answer:
C. Inhibit H+/K+-ATPase in parietal cells
Rationale:
PPIs block gastric acid secretion by irreversibly inhibiting the H+/K+-ATPase enzyme in
parietal cells, producing a profound and long-lasting antisecretory effect that maintains
,gastric pH above 4. They are the most effective for patients with moderate to severe GERD
symptoms and promote healing of gastric and esophageal ulcerations. Maintenance
therapy can include on-demand use for symptom recurrence.
Question:
Which of the following is NOT a common cause of peptic ulcer disease (PUD)?
Options:
A. H. pylori infection
B. Chronic NSAID use
C. Zollinger-Ellison syndrome
D. Short-term steroid use alone
Answer:
D. Short-term steroid use alone
Rationale:
PUD is commonly caused by H. pylori infection, chronic NSAID use (risk increased with
corticosteroids), stress-related mucosal damage in critically ill patients, and Zollinger-
Ellison syndrome (gastrinoma causing hypersecretion). Short-term steroid use by itself is
not a significant risk factor.
Question:
Scopolamine is primarily used for which purpose?
Options:
A. Treat GERD
B. Prevent and treat motion sickness and postoperative nausea and vomiting (PONV)
C. Promote gastric emptying
D. Reduce gastric acid secretion
Answer:
B. Prevent and treat motion sickness and postoperative nausea and vomiting (PONV)
Rationale:
Scopolamine is an anticholinergic that blocks muscarinic receptors in the vestibular
system, preventing signals from reaching the CNS. It can be delivered via a transdermal
patch for up to 72 hours. Side effects include dizziness, dry mouth, visual disturbances,
and sedation.
,Question:
Why are first-generation antihistamines effective in preventing nausea and vomiting?
Options:
A. They inhibit dopamine receptors in the chemoreceptor trigger zone
B. They block H1 receptors in the vestibular system
C. They inhibit gastric acid secretion
D. They enhance gastric motility
Answer:
B. They block H1 receptors in the vestibular system
Rationale:
First-generation antihistamines prevent and treat nausea and vomiting, including motion
sickness and vertigo, by acting on H1 receptors in the vestibular system. They can cause
drowsiness, blurry vision, and urinary retention. Second-generation antihistamines are
less effective for this purpose because they do not cross the blood-brain barrier.
Question:
Phenothiazines like promethazine are used for nausea and vomiting because they:
Options:
A. Act as H2 receptor antagonists
B. Block muscarinic receptors
C. Block dopamine receptors in the chemoreceptor trigger zone (CTZ)
D. Inhibit gastric acid secretion
Answer:
C. Block dopamine receptors in the chemoreceptor trigger zone (CTZ)
Rationale:
Phenothiazines treat severe motion sickness, nausea and vomiting in pregnancy (NVP),
PONV, and chemotherapy-induced nausea and vomiting (CINV). Side effects include
extrapyramidal symptoms (EPS), sedation, and orthostatic hypotension.
Question:
Butyrophenones such as droperidol and haloperidol are primarily used for:
Options:
A. GERD
B. PONV and CINV
C. Acid suppression
D. Motion sickness
, Answer:
B. PONV and CINV
Rationale:
Butyrophenones are effective antiemetics for postoperative and chemotherapy-induced
nausea and vomiting but carry a Black Box warning for prolonged QT interval, which can
increase the risk of cardiac arrhythmias.
Question:
Prokinetic agents like metoclopramide and domperidone work by:
Options:
A. Inhibiting H2 receptors
B. Increasing lower esophageal sphincter (LES) tone and promoting gastric motility
C. Blocking serotonin receptors
D. Reducing CNS dopamine activity exclusively
Answer:
B. Increasing lower esophageal sphincter (LES) tone and promoting gastric motility
Rationale:
Prokinetic agents improve LES tone and enhance gastric emptying, making them useful for
PONV, CINV, gastroparesis, and GERD. Metoclopramide crosses the blood-brain barrier,
which can contribute to central nervous system side effects.
Question:
Corticosteroids like dexamethasone and methylprednisolone are used in antiemetic
therapy because they:
Options:
A. Inhibit H+/K+-ATPase in parietal cells
B. Reduce gastric acid secretion
C. Prevent and treat PONV, CINV, and radiation-induced nausea
D. Act as dopamine antagonists in the CTZ
Answer:
C. Prevent and treat PONV, CINV, and radiation-induced nausea
Rationale:
Corticosteroids are effective antiemetics when used alone or in combination with other
agents. Their precise mechanism in preventing nausea is not fully understood but is highly
effective for postoperative, chemotherapy, and radiation-induced nausea and vomiting.
Questions and Verified Answers | 100% Correct |
Grade A | over 80+ quiz with advanced
rationales download now
Question:
What is the mechanism of action of Histamine-2 Receptor Antagonists (H2RAs) such as
cimetidine, famotidine, nizatidine, and ranitidine?
Options:
A. Stimulate gastric acid secretion
B. Block histamine receptors in gastric parietal cells
C. Inhibit H+/K+-ATPase in parietal cells
D. Neutralize gastric acid directly
Answer:
B. Block histamine receptors in gastric parietal cells
Rationale:
H2RAs decrease acid secretion by blocking H2 receptors on gastric parietal cells. They
provide relief from acute GERD symptoms and can be used prophylactically. While more
effective than antacids for chronic GERD, they are less potent than PPIs. Famotidine is
considered the most effective in the class for acid suppression and ulcer healing.
Question:
Which statement correctly describes the action of Proton Pump Inhibitors (PPIs) like
omeprazole, pantoprazole, and lansoprazole?
Options:
A. Neutralize gastric acid immediately
B. Block histamine receptors in parietal cells
C. Inhibit H+/K+-ATPase in parietal cells
D. Stimulate gastric emptying
Answer:
C. Inhibit H+/K+-ATPase in parietal cells
Rationale:
PPIs block gastric acid secretion by irreversibly inhibiting the H+/K+-ATPase enzyme in
parietal cells, producing a profound and long-lasting antisecretory effect that maintains
,gastric pH above 4. They are the most effective for patients with moderate to severe GERD
symptoms and promote healing of gastric and esophageal ulcerations. Maintenance
therapy can include on-demand use for symptom recurrence.
Question:
Which of the following is NOT a common cause of peptic ulcer disease (PUD)?
Options:
A. H. pylori infection
B. Chronic NSAID use
C. Zollinger-Ellison syndrome
D. Short-term steroid use alone
Answer:
D. Short-term steroid use alone
Rationale:
PUD is commonly caused by H. pylori infection, chronic NSAID use (risk increased with
corticosteroids), stress-related mucosal damage in critically ill patients, and Zollinger-
Ellison syndrome (gastrinoma causing hypersecretion). Short-term steroid use by itself is
not a significant risk factor.
Question:
Scopolamine is primarily used for which purpose?
Options:
A. Treat GERD
B. Prevent and treat motion sickness and postoperative nausea and vomiting (PONV)
C. Promote gastric emptying
D. Reduce gastric acid secretion
Answer:
B. Prevent and treat motion sickness and postoperative nausea and vomiting (PONV)
Rationale:
Scopolamine is an anticholinergic that blocks muscarinic receptors in the vestibular
system, preventing signals from reaching the CNS. It can be delivered via a transdermal
patch for up to 72 hours. Side effects include dizziness, dry mouth, visual disturbances,
and sedation.
,Question:
Why are first-generation antihistamines effective in preventing nausea and vomiting?
Options:
A. They inhibit dopamine receptors in the chemoreceptor trigger zone
B. They block H1 receptors in the vestibular system
C. They inhibit gastric acid secretion
D. They enhance gastric motility
Answer:
B. They block H1 receptors in the vestibular system
Rationale:
First-generation antihistamines prevent and treat nausea and vomiting, including motion
sickness and vertigo, by acting on H1 receptors in the vestibular system. They can cause
drowsiness, blurry vision, and urinary retention. Second-generation antihistamines are
less effective for this purpose because they do not cross the blood-brain barrier.
Question:
Phenothiazines like promethazine are used for nausea and vomiting because they:
Options:
A. Act as H2 receptor antagonists
B. Block muscarinic receptors
C. Block dopamine receptors in the chemoreceptor trigger zone (CTZ)
D. Inhibit gastric acid secretion
Answer:
C. Block dopamine receptors in the chemoreceptor trigger zone (CTZ)
Rationale:
Phenothiazines treat severe motion sickness, nausea and vomiting in pregnancy (NVP),
PONV, and chemotherapy-induced nausea and vomiting (CINV). Side effects include
extrapyramidal symptoms (EPS), sedation, and orthostatic hypotension.
Question:
Butyrophenones such as droperidol and haloperidol are primarily used for:
Options:
A. GERD
B. PONV and CINV
C. Acid suppression
D. Motion sickness
, Answer:
B. PONV and CINV
Rationale:
Butyrophenones are effective antiemetics for postoperative and chemotherapy-induced
nausea and vomiting but carry a Black Box warning for prolonged QT interval, which can
increase the risk of cardiac arrhythmias.
Question:
Prokinetic agents like metoclopramide and domperidone work by:
Options:
A. Inhibiting H2 receptors
B. Increasing lower esophageal sphincter (LES) tone and promoting gastric motility
C. Blocking serotonin receptors
D. Reducing CNS dopamine activity exclusively
Answer:
B. Increasing lower esophageal sphincter (LES) tone and promoting gastric motility
Rationale:
Prokinetic agents improve LES tone and enhance gastric emptying, making them useful for
PONV, CINV, gastroparesis, and GERD. Metoclopramide crosses the blood-brain barrier,
which can contribute to central nervous system side effects.
Question:
Corticosteroids like dexamethasone and methylprednisolone are used in antiemetic
therapy because they:
Options:
A. Inhibit H+/K+-ATPase in parietal cells
B. Reduce gastric acid secretion
C. Prevent and treat PONV, CINV, and radiation-induced nausea
D. Act as dopamine antagonists in the CTZ
Answer:
C. Prevent and treat PONV, CINV, and radiation-induced nausea
Rationale:
Corticosteroids are effective antiemetics when used alone or in combination with other
agents. Their precise mechanism in preventing nausea is not fully understood but is highly
effective for postoperative, chemotherapy, and radiation-induced nausea and vomiting.
