NCLEX-RN Pharmacology Exam Questions
& Answers |
Gastrointestinal System |
20 ATI & NGN-Style Practice MCQs with
Rationales
Question 1
Clinical Scenario
A 68-year-old female with a history of gastroesophageal reflux
disease (GERD) presents to the clinic complaining of new-onset
muscle cramps, tremors, and occasional palpitations. She reports
taking omeprazole 40 mg daily for the past 3 years. Her vital signs
are within normal limits, and her electrocardiogram (ECG) shows
occasional premature ventricular contractions (PVCs).
Question Stem
Which laboratory value should the nurse review first to determine
the cause of the client’s symptoms?
,A. Serum magnesium
B. Serum sodium
C. Blood urea nitrogen (BUN)
D. White blood cell count
Correct Answer
Correct Answer: A. Serum magnesium
Detailed Rationale
Long-term use of proton pump inhibitors (PPIs), such as
omeprazole, is associated with an increased risk of
hypomagnesemia, particularly after 1 year of continuous therapy.
Hypomagnesemia can manifest clinically with neuromuscular
irritability (muscle cramps, tremors, tetany) and cardiac
dysrhythmias (such as the PVCs noted in this client). The nurse
should prioritize reviewing the serum magnesium level to confirm
this adverse effect. If hypomagnesemia is confirmed, the provider
may order magnesium supplementation and evaluate the need to
discontinue or switch the PPI. Serum sodium (Option B) imbalances
typically present with confusion, lethargy, or seizures, not isolated
muscle cramps and palpitations. BUN (Option C) is used to assess
renal function and hydration status, which is not the primary
concern given the specific symptom cluster and medication history.
White blood cell count (Option D) is used to evaluate for infection or
inflammation, which is not suggested by the client’s presentation.
Learning Objective
• Identify hypomagnesemia as a potential adverse effect of long-
term proton pump inhibitor therapy.
, • Recognize the clinical manifestations of hypomagnesemia,
including neuromuscular and cardiac symptoms.
• Prioritize appropriate laboratory monitoring for clients on
chronic PPI therapy.
Medication Safety Focus
Adverse effect monitoring and long-term medication safety.
Question 2
Clinical Scenario
A 55-year-old male with a history of heart failure and a known
prolonged QT interval is admitted for chemotherapy-induced
nausea and vomiting. The provider prescribes ondansetron 8 mg IV
push prior to the chemotherapy infusion. The client’s current
potassium level is 3.4 mEq/L.
Question Stem
Which action is the priority for the nurse before administering this
medication?
A. Assess the client’s bowel sounds.
B. Administer the medication with a full glass of water.
C. Check the client’s serum potassium level again.
D. Review the client’s most recent electrocardiogram (ECG).
Correct Answer
Correct Answer: D. Review the client’s most recent
electrocardiogram (ECG).
, Detailed Rationale
Ondansetron, a serotonin (5-HT3) receptor antagonist, carries a risk
of dose-dependent QT interval prolongation, which can lead to life-
threatening dysrhythmias such as torsades de pointes. This risk is
significantly amplified in clients with preexisting heart conditions, a
known prolonged QT interval, or electrolyte imbalances (such as the
borderline low potassium of 3.4 mEq/L seen in this client). The
priority nursing action is to review the most recent ECG to assess
the current QT interval before administering the medication. If the
QT interval is significantly prolonged, the nurse must hold the
medication and notify the provider. Assessing bowel sounds (Option
A) is not a priority for an antiemetic. Ondansetron IV is not
administered with water (Option B). While checking potassium
(Option C) is relevant, the immediate safety check before giving a
QT-prolonging drug to a high-risk client is evaluating the cardiac
rhythm via ECG.
Learning Objective
• Recognize QT prolongation as a serious adverse effect of
ondansetron.
• Identify risk factors that increase the likelihood of
ondansetron-induced dysrhythmias.
• Prioritize ECG review before administering QT-prolonging
medications to high-risk clients.
Medication Safety Focus
High-alert medication administration and cardiac monitoring.
& Answers |
Gastrointestinal System |
20 ATI & NGN-Style Practice MCQs with
Rationales
Question 1
Clinical Scenario
A 68-year-old female with a history of gastroesophageal reflux
disease (GERD) presents to the clinic complaining of new-onset
muscle cramps, tremors, and occasional palpitations. She reports
taking omeprazole 40 mg daily for the past 3 years. Her vital signs
are within normal limits, and her electrocardiogram (ECG) shows
occasional premature ventricular contractions (PVCs).
Question Stem
Which laboratory value should the nurse review first to determine
the cause of the client’s symptoms?
,A. Serum magnesium
B. Serum sodium
C. Blood urea nitrogen (BUN)
D. White blood cell count
Correct Answer
Correct Answer: A. Serum magnesium
Detailed Rationale
Long-term use of proton pump inhibitors (PPIs), such as
omeprazole, is associated with an increased risk of
hypomagnesemia, particularly after 1 year of continuous therapy.
Hypomagnesemia can manifest clinically with neuromuscular
irritability (muscle cramps, tremors, tetany) and cardiac
dysrhythmias (such as the PVCs noted in this client). The nurse
should prioritize reviewing the serum magnesium level to confirm
this adverse effect. If hypomagnesemia is confirmed, the provider
may order magnesium supplementation and evaluate the need to
discontinue or switch the PPI. Serum sodium (Option B) imbalances
typically present with confusion, lethargy, or seizures, not isolated
muscle cramps and palpitations. BUN (Option C) is used to assess
renal function and hydration status, which is not the primary
concern given the specific symptom cluster and medication history.
White blood cell count (Option D) is used to evaluate for infection or
inflammation, which is not suggested by the client’s presentation.
Learning Objective
• Identify hypomagnesemia as a potential adverse effect of long-
term proton pump inhibitor therapy.
, • Recognize the clinical manifestations of hypomagnesemia,
including neuromuscular and cardiac symptoms.
• Prioritize appropriate laboratory monitoring for clients on
chronic PPI therapy.
Medication Safety Focus
Adverse effect monitoring and long-term medication safety.
Question 2
Clinical Scenario
A 55-year-old male with a history of heart failure and a known
prolonged QT interval is admitted for chemotherapy-induced
nausea and vomiting. The provider prescribes ondansetron 8 mg IV
push prior to the chemotherapy infusion. The client’s current
potassium level is 3.4 mEq/L.
Question Stem
Which action is the priority for the nurse before administering this
medication?
A. Assess the client’s bowel sounds.
B. Administer the medication with a full glass of water.
C. Check the client’s serum potassium level again.
D. Review the client’s most recent electrocardiogram (ECG).
Correct Answer
Correct Answer: D. Review the client’s most recent
electrocardiogram (ECG).
, Detailed Rationale
Ondansetron, a serotonin (5-HT3) receptor antagonist, carries a risk
of dose-dependent QT interval prolongation, which can lead to life-
threatening dysrhythmias such as torsades de pointes. This risk is
significantly amplified in clients with preexisting heart conditions, a
known prolonged QT interval, or electrolyte imbalances (such as the
borderline low potassium of 3.4 mEq/L seen in this client). The
priority nursing action is to review the most recent ECG to assess
the current QT interval before administering the medication. If the
QT interval is significantly prolonged, the nurse must hold the
medication and notify the provider. Assessing bowel sounds (Option
A) is not a priority for an antiemetic. Ondansetron IV is not
administered with water (Option B). While checking potassium
(Option C) is relevant, the immediate safety check before giving a
QT-prolonging drug to a high-risk client is evaluating the cardiac
rhythm via ECG.
Learning Objective
• Recognize QT prolongation as a serious adverse effect of
ondansetron.
• Identify risk factors that increase the likelihood of
ondansetron-induced dysrhythmias.
• Prioritize ECG review before administering QT-prolonging
medications to high-risk clients.
Medication Safety Focus
High-alert medication administration and cardiac monitoring.
