NCLEX-RN Pharmacology Made Easy:
Gastrointestinal System Practice
Questions |
20 ATI & NGN-Style MCQs with Detailed
Rationales |
Nursing Exam Study Guide
Question 1
Clinical Scenario
A 54-year-old male client is admitted to the medical-surgical unit
with a newly diagnosed gastric ulcer. The healthcare provider
prescribes omeprazole 20 mg orally once daily. The client asks the
nurse when the best time is to take this medication.
Question Stem
Which statement by the nurse provides the most accurate
instruction regarding the administration of omeprazole?
A. "Take this medication with your largest meal of the day to prevent
stomach upset."
B. "Take this medication 30 to 60 minutes before your first meal of
the day."
,C. "Take this medication at bedtime with a full glass of milk to
maximize absorption."
D. "Take this medication immediately after eating to coat the
stomach lining."
Correct Answer
Correct Answer: B. "Take this medication 30 to 60 minutes before
your first meal of the day."
Detailed Rationale
Omeprazole is a proton pump inhibitor (PPI) that irreversibly binds to
the H+/K+ ATPase enzyme system (the proton pump) of the gastric
parietal cell. For maximal efficacy, PPIs should be administered 30
to 60 minutes before the first meal of the day. This timing ensures
that the medication is absorbed and reaches peak plasma
concentrations just as the meal stimulates the activation of new
proton pumps, allowing the drug to effectively block acid secretion.
Taking omeprazole with food (Option A), at bedtime with milk
(Option C), or immediately after eating (Option D) significantly
delays and decreases its absorption, reducing its therapeutic effect
in healing the gastric ulcer. Nursing considerations include advising
the client to swallow the capsule whole, as it contains enteric-
coated granules that should not be crushed or chewed. Long-term
PPI use also requires monitoring for potential adverse effects such
as hypomagnesemia, vitamin B12 deficiency, and increased risk of
Clostridioides difficile infection.
Learning Objective
• Identify the optimal timing for administering proton pump
inhibitors to maximize therapeutic efficacy.
, • Explain the mechanism of action of omeprazole in relation to
meal stimulation.
• Educate patients on proper administration and long-term
monitoring requirements for PPIs.
Medication Safety Focus
Medication administration
Question 2
Clinical Scenario
A 68-year-old female client with a history of heart failure and chronic
kidney disease (stage 3) is experiencing severe postoperative
nausea. The provider prescribes ondansetron 4 mg IV push. The
nurse reviews the client’s electronic health record before
administration.
Question Stem
Which finding in the client’s medical record requires the nurse to
contact the healthcare provider before administering ondansetron?
A. Potassium level of 3.6 mEq/L
B. History of prolonged QT interval on a recent ECG
C. Blood pressure of 138/88 mm Hg
D. Reported allergy to shellfish
Correct Answer
Correct Answer: B. History of prolonged QT interval on a recent ECG
Detailed Rationale
Ondansetron, a serotonin (5-HT3) receptor antagonist, is highly
, effective for nausea and vomiting but carries a Black Box Warning
for dose-dependent QT interval prolongation, which can lead to
torsades de pointes, a life-threatening ventricular arrhythmia. This
risk is significantly heightened in clients with preexisting cardiac
conditions, electrolyte imbalances (such as hypokalemia or
hypomagnesemia), or those taking other QT-prolonging
medications. A history of a prolonged QT interval is a strong
contraindication or requires extreme caution and provider
clarification before administration. A potassium level of 3.6 mEq/L
(Option A) is within the lower limit of normal (3.5–5.0 mEq/L) and
does not independently contraindicate use, though it should be
monitored. Blood pressure of 138/88 mm Hg (Option C) is
acceptable. Ondansetron does not have cross-reactivity with
shellfish allergies (Option D), as it is not derived from marine
sources. The nurse must prioritize cardiac safety by verifying the
ECG findings with the provider.
Learning Objective
• Recognize the Black Box Warning associated with ondansetron
regarding QT prolongation.
• Prioritize assessment of cardiac history and electrolyte levels
before administering antiemetics.
• Identify when to withhold a medication and contact the
healthcare provider for clarification.
Medication Safety Focus
Black Box Warning
Gastrointestinal System Practice
Questions |
20 ATI & NGN-Style MCQs with Detailed
Rationales |
Nursing Exam Study Guide
Question 1
Clinical Scenario
A 54-year-old male client is admitted to the medical-surgical unit
with a newly diagnosed gastric ulcer. The healthcare provider
prescribes omeprazole 20 mg orally once daily. The client asks the
nurse when the best time is to take this medication.
Question Stem
Which statement by the nurse provides the most accurate
instruction regarding the administration of omeprazole?
A. "Take this medication with your largest meal of the day to prevent
stomach upset."
B. "Take this medication 30 to 60 minutes before your first meal of
the day."
,C. "Take this medication at bedtime with a full glass of milk to
maximize absorption."
D. "Take this medication immediately after eating to coat the
stomach lining."
Correct Answer
Correct Answer: B. "Take this medication 30 to 60 minutes before
your first meal of the day."
Detailed Rationale
Omeprazole is a proton pump inhibitor (PPI) that irreversibly binds to
the H+/K+ ATPase enzyme system (the proton pump) of the gastric
parietal cell. For maximal efficacy, PPIs should be administered 30
to 60 minutes before the first meal of the day. This timing ensures
that the medication is absorbed and reaches peak plasma
concentrations just as the meal stimulates the activation of new
proton pumps, allowing the drug to effectively block acid secretion.
Taking omeprazole with food (Option A), at bedtime with milk
(Option C), or immediately after eating (Option D) significantly
delays and decreases its absorption, reducing its therapeutic effect
in healing the gastric ulcer. Nursing considerations include advising
the client to swallow the capsule whole, as it contains enteric-
coated granules that should not be crushed or chewed. Long-term
PPI use also requires monitoring for potential adverse effects such
as hypomagnesemia, vitamin B12 deficiency, and increased risk of
Clostridioides difficile infection.
Learning Objective
• Identify the optimal timing for administering proton pump
inhibitors to maximize therapeutic efficacy.
, • Explain the mechanism of action of omeprazole in relation to
meal stimulation.
• Educate patients on proper administration and long-term
monitoring requirements for PPIs.
Medication Safety Focus
Medication administration
Question 2
Clinical Scenario
A 68-year-old female client with a history of heart failure and chronic
kidney disease (stage 3) is experiencing severe postoperative
nausea. The provider prescribes ondansetron 4 mg IV push. The
nurse reviews the client’s electronic health record before
administration.
Question Stem
Which finding in the client’s medical record requires the nurse to
contact the healthcare provider before administering ondansetron?
A. Potassium level of 3.6 mEq/L
B. History of prolonged QT interval on a recent ECG
C. Blood pressure of 138/88 mm Hg
D. Reported allergy to shellfish
Correct Answer
Correct Answer: B. History of prolonged QT interval on a recent ECG
Detailed Rationale
Ondansetron, a serotonin (5-HT3) receptor antagonist, is highly
, effective for nausea and vomiting but carries a Black Box Warning
for dose-dependent QT interval prolongation, which can lead to
torsades de pointes, a life-threatening ventricular arrhythmia. This
risk is significantly heightened in clients with preexisting cardiac
conditions, electrolyte imbalances (such as hypokalemia or
hypomagnesemia), or those taking other QT-prolonging
medications. A history of a prolonged QT interval is a strong
contraindication or requires extreme caution and provider
clarification before administration. A potassium level of 3.6 mEq/L
(Option A) is within the lower limit of normal (3.5–5.0 mEq/L) and
does not independently contraindicate use, though it should be
monitored. Blood pressure of 138/88 mm Hg (Option C) is
acceptable. Ondansetron does not have cross-reactivity with
shellfish allergies (Option D), as it is not derived from marine
sources. The nurse must prioritize cardiac safety by verifying the
ECG findings with the provider.
Learning Objective
• Recognize the Black Box Warning associated with ondansetron
regarding QT prolongation.
• Prioritize assessment of cardiac history and electrolyte levels
before administering antiemetics.
• Identify when to withhold a medication and contact the
healthcare provider for clarification.
Medication Safety Focus
Black Box Warning
