NCLEX-RN Pharmacology Gastrointestinal
System Exam |
20 ATI & NGN-Style Practice Questions
with Rationales |
Nursing Pharmacology Study Guide
Question 1
Clinical Scenario
A 54-year-old male client is newly diagnosed with gastroesophageal
reflux disease (GERD). The provider prescribes omeprazole 20 mg
orally once daily. The client asks the nurse when is the best time to
take this medication to ensure it works effectively.
Question Stem
Which response by the nurse provides the most accurate patient
teaching regarding the administration of omeprazole?
A. "Take this medication at bedtime with a full glass of milk to
prevent stomach upset."
B. "Take this medication 30 to 60 minutes before your first meal of
the day."
C. "Take this medication immediately after your largest meal to
neutralize the acid."
,D. "Take this medication on an empty stomach right before going to
sleep."
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 must be administered 30 to
60 minutes before a meal (typically breakfast). This timing ensures
that the medication is absorbed and reaches peak plasma
concentrations precisely when the meal stimulates the activation of
new proton pumps, allowing the drug to effectively block acid
secretion. Option A is incorrect because taking it at bedtime with
milk does not align with the pharmacokinetic need for meal-
stimulated pump activation, and milk can temporarily buffer acid
but may later stimulate more acid production. Option C is incorrect
because taking it after a meal misses the window of maximal pump
activation, significantly reducing its therapeutic effect. Option D is
incorrect because taking it right before sleep on an empty stomach
does not provide the necessary meal stimulus for optimal drug
action. Nurses must emphasize this timing to ensure clinical
effectiveness and prevent treatment failure.
Learning Objective
• Explain the optimal timing for administering proton pump
inhibitors to maximize therapeutic effect.
, • Educate patients on the pharmacokinetic relationship
between meal consumption and PPI efficacy.
• Differentiate between antacid administration and PPI
administration schedules.
Medication Safety Focus
Medication administration timing
Question 2
Clinical Scenario
A 62-year-old female client with a history of heart failure and a
baseline QT interval of 480 msec is admitted for severe nausea and
vomiting secondary to chemotherapy. The provider prescribes
ondansetron 4 mg IV push.
Question Stem
Which action should the nurse take priority before administering
this medication?
A. Administer the medication slowly over 15 minutes to prevent
hypotension.
B. Assess the client’s bowel sounds to rule out a paralytic ileus.
C. Obtain a 12-lead electrocardiogram (ECG) and notify the provider
of the prolonged QT interval.
D. Request a prescription for an alternative antiemetic, such as
promethazine, due to the cardiac history.
, Correct Answer
Correct Answer: C. Obtain a 12-lead electrocardiogram (ECG) and
notify the provider of the prolonged QT interval.
Detailed Rationale
Ondansetron, a serotonin (5-HT3) receptor antagonist, carries a
known risk of dose-dependent QT interval prolongation, which can
lead to life-threatening arrhythmias such as Torsades de Pointes. A
baseline QT interval of 480 msec is already prolonged (normal is
typically < 450 msec in men and < 460 msec in women).
Administering ondansetron to a client with pre-existing QT
prolongation, electrolyte imbalances (e.g., hypokalemia,
hypomagnesemia), or concurrent use of other QT-prolonging drugs
is contraindicated or requires extreme caution. The priority nursing
action is to obtain an ECG to verify the current QT interval and notify
the provider before administration. Option A is incorrect because
while IV ondansetron should be given slowly (over at least 2-5
minutes) to prevent adverse effects, the primary safety concern here
is the arrhythmia risk, not hypotension. Option B is a good
assessment but not the priority given the specific cardiac risk.
Option D is incorrect because promethazine also carries a risk of QT
prolongation and is not a safer alternative without provider
evaluation.
Learning Objective
• Recognize QT interval prolongation as a serious adverse effect
of ondansetron.
• Prioritize cardiac assessment and provider notification for
clients with pre-existing ECG abnormalities.
System Exam |
20 ATI & NGN-Style Practice Questions
with Rationales |
Nursing Pharmacology Study Guide
Question 1
Clinical Scenario
A 54-year-old male client is newly diagnosed with gastroesophageal
reflux disease (GERD). The provider prescribes omeprazole 20 mg
orally once daily. The client asks the nurse when is the best time to
take this medication to ensure it works effectively.
Question Stem
Which response by the nurse provides the most accurate patient
teaching regarding the administration of omeprazole?
A. "Take this medication at bedtime with a full glass of milk to
prevent stomach upset."
B. "Take this medication 30 to 60 minutes before your first meal of
the day."
C. "Take this medication immediately after your largest meal to
neutralize the acid."
,D. "Take this medication on an empty stomach right before going to
sleep."
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 must be administered 30 to
60 minutes before a meal (typically breakfast). This timing ensures
that the medication is absorbed and reaches peak plasma
concentrations precisely when the meal stimulates the activation of
new proton pumps, allowing the drug to effectively block acid
secretion. Option A is incorrect because taking it at bedtime with
milk does not align with the pharmacokinetic need for meal-
stimulated pump activation, and milk can temporarily buffer acid
but may later stimulate more acid production. Option C is incorrect
because taking it after a meal misses the window of maximal pump
activation, significantly reducing its therapeutic effect. Option D is
incorrect because taking it right before sleep on an empty stomach
does not provide the necessary meal stimulus for optimal drug
action. Nurses must emphasize this timing to ensure clinical
effectiveness and prevent treatment failure.
Learning Objective
• Explain the optimal timing for administering proton pump
inhibitors to maximize therapeutic effect.
, • Educate patients on the pharmacokinetic relationship
between meal consumption and PPI efficacy.
• Differentiate between antacid administration and PPI
administration schedules.
Medication Safety Focus
Medication administration timing
Question 2
Clinical Scenario
A 62-year-old female client with a history of heart failure and a
baseline QT interval of 480 msec is admitted for severe nausea and
vomiting secondary to chemotherapy. The provider prescribes
ondansetron 4 mg IV push.
Question Stem
Which action should the nurse take priority before administering
this medication?
A. Administer the medication slowly over 15 minutes to prevent
hypotension.
B. Assess the client’s bowel sounds to rule out a paralytic ileus.
C. Obtain a 12-lead electrocardiogram (ECG) and notify the provider
of the prolonged QT interval.
D. Request a prescription for an alternative antiemetic, such as
promethazine, due to the cardiac history.
, Correct Answer
Correct Answer: C. Obtain a 12-lead electrocardiogram (ECG) and
notify the provider of the prolonged QT interval.
Detailed Rationale
Ondansetron, a serotonin (5-HT3) receptor antagonist, carries a
known risk of dose-dependent QT interval prolongation, which can
lead to life-threatening arrhythmias such as Torsades de Pointes. A
baseline QT interval of 480 msec is already prolonged (normal is
typically < 450 msec in men and < 460 msec in women).
Administering ondansetron to a client with pre-existing QT
prolongation, electrolyte imbalances (e.g., hypokalemia,
hypomagnesemia), or concurrent use of other QT-prolonging drugs
is contraindicated or requires extreme caution. The priority nursing
action is to obtain an ECG to verify the current QT interval and notify
the provider before administration. Option A is incorrect because
while IV ondansetron should be given slowly (over at least 2-5
minutes) to prevent adverse effects, the primary safety concern here
is the arrhythmia risk, not hypotension. Option B is a good
assessment but not the priority given the specific cardiac risk.
Option D is incorrect because promethazine also carries a risk of QT
prolongation and is not a safer alternative without provider
evaluation.
Learning Objective
• Recognize QT interval prolongation as a serious adverse effect
of ondansetron.
• Prioritize cardiac assessment and provider notification for
clients with pre-existing ECG abnormalities.
