,NU 150 — Exam 4: Advanced Pharmacology and Clinical Decision
Making; Comprehensive Questions & Verified Answers — Spring 2026
Edition
1. Which of the following best defines the therapeutic index of a drug?
A) The ratio of the median lethal dose to the median effective dose
B) The time it takes for a drug to reach peak plasma concentration
C) The percentage of drug bound to plasma proteins
D) The volume of distribution in the body
Correct Answer: The ratio of the median lethal dose to the median effective dose
Rationale: Therapeutic index is calculated as TD50/ED50 or LD50/ED50. A narrow therapeutic index
indicates a small margin between effective and toxic doses, requiring close monitoring. Plasma protein
binding, volume of distribution, and time to peak are separate pharmacokinetic parameters.
2. The nurse is caring for an older adult patient who is taking multiple medications. Which age-related
change most significantly alters drug metabolism?
A) Decreased gastric acid secretion
B) Reduced liver mass and blood flow
C) Increased adipose tissue
D) Decreased renal blood flow
Correct Answer: Reduced liver mass and blood flow
Rationale: Hepatic metabolism is the primary route of drug biotransformation, and aging reduces liver
mass and hepatic blood flow, slowing phase I oxidative reactions. Decreased gastric acid affects
absorption, increased fat alters distribution, and reduced renal flow impairs excretion.
3. The nurse is teaching a patient prescribed warfarin about potential drug interactions. Which over-the-
counter product should the patient avoid?
A) Acetaminophen
,B) Calcium carbonate
C) Aspirin
D) Diphenhydramine
Correct Answer: Aspirin
Rationale: Aspirin inhibits platelet aggregation and can cause gastric bleeding; combined with warfarin,
the risk of hemorrhage is significantly increased. Acetaminophen in high doses can also interact but is
generally safer; calcium carbonate and diphenhydramine have less interaction.
4. A patient is receiving gentamicin for a severe infection. Which laboratory test is essential to monitor
for nephrotoxicity?
A) Serum creatinine and blood urea nitrogen
B) Alanine aminotransferase
C) Complete blood count
D) Serum glucose
Correct Answer: Serum creatinine and blood urea nitrogen
Rationale: Aminoglycosides like gentamicin are nephrotoxic; rising creatinine and BUN indicate renal
impairment. Peak and trough levels are also monitored to maintain therapeutic and safe dosing. Liver
enzymes, CBC, and glucose are not primary indicators of gentamicin toxicity.
5. The nurse is caring for a patient receiving lithium. Which serum level indicates toxicity?
A) 0.8 mEq/L
B) 1.1 mEq/L
C) 1.6 mEq/L
D) 2.2 mEq/L
Correct Answer: 2.2 mEq/L
, Rationale: Therapeutic lithium levels are 0.6-1.2 mEq/L; levels above 1.5 mEq/L indicate toxicity. A level
of 2.2 mEq/L is toxic and can cause severe neurological and cardiac complications. Maintenance levels
and regular monitoring are critical.
6. The nurse is assessing a patient who is taking digoxin. Which finding would prompt the nurse to
withhold the medication and notify the provider?
A) Blood pressure 130/80 mmHg
B) Apical pulse 56 beats per minute
C) Serum potassium 4.2 mEq/L
D) Respiratory rate 18 breaths per minute
Correct Answer: Apical pulse 56 beats per minute
Rationale: Digoxin can cause bradycardia; the nurse should hold the dose if the apical pulse is below 60
bpm in adults (or per specific order). Blood pressure, normal potassium, and respiratory rate are not
reasons to withhold. Bradycardia may indicate digoxin toxicity.
7. A patient is prescribed metformin for type 2 diabetes. Which condition should the nurse identify as a
contraindication?
A) Obesity
B) Hyperlipidemia
C) Renal impairment with creatinine clearance below 30 mL/min
D) Hypertension
Correct Answer: Renal impairment with creatinine clearance below 30 mL/min
Rationale: Metformin is contraindicated in significant renal impairment because of the risk of lactic
acidosis, a rare but life-threatening complication. It is not contraindicated with obesity, hyperlipidemia,
or hypertension alone, though caution is used with hepatic disease.
Making; Comprehensive Questions & Verified Answers — Spring 2026
Edition
1. Which of the following best defines the therapeutic index of a drug?
A) The ratio of the median lethal dose to the median effective dose
B) The time it takes for a drug to reach peak plasma concentration
C) The percentage of drug bound to plasma proteins
D) The volume of distribution in the body
Correct Answer: The ratio of the median lethal dose to the median effective dose
Rationale: Therapeutic index is calculated as TD50/ED50 or LD50/ED50. A narrow therapeutic index
indicates a small margin between effective and toxic doses, requiring close monitoring. Plasma protein
binding, volume of distribution, and time to peak are separate pharmacokinetic parameters.
2. The nurse is caring for an older adult patient who is taking multiple medications. Which age-related
change most significantly alters drug metabolism?
A) Decreased gastric acid secretion
B) Reduced liver mass and blood flow
C) Increased adipose tissue
D) Decreased renal blood flow
Correct Answer: Reduced liver mass and blood flow
Rationale: Hepatic metabolism is the primary route of drug biotransformation, and aging reduces liver
mass and hepatic blood flow, slowing phase I oxidative reactions. Decreased gastric acid affects
absorption, increased fat alters distribution, and reduced renal flow impairs excretion.
3. The nurse is teaching a patient prescribed warfarin about potential drug interactions. Which over-the-
counter product should the patient avoid?
A) Acetaminophen
,B) Calcium carbonate
C) Aspirin
D) Diphenhydramine
Correct Answer: Aspirin
Rationale: Aspirin inhibits platelet aggregation and can cause gastric bleeding; combined with warfarin,
the risk of hemorrhage is significantly increased. Acetaminophen in high doses can also interact but is
generally safer; calcium carbonate and diphenhydramine have less interaction.
4. A patient is receiving gentamicin for a severe infection. Which laboratory test is essential to monitor
for nephrotoxicity?
A) Serum creatinine and blood urea nitrogen
B) Alanine aminotransferase
C) Complete blood count
D) Serum glucose
Correct Answer: Serum creatinine and blood urea nitrogen
Rationale: Aminoglycosides like gentamicin are nephrotoxic; rising creatinine and BUN indicate renal
impairment. Peak and trough levels are also monitored to maintain therapeutic and safe dosing. Liver
enzymes, CBC, and glucose are not primary indicators of gentamicin toxicity.
5. The nurse is caring for a patient receiving lithium. Which serum level indicates toxicity?
A) 0.8 mEq/L
B) 1.1 mEq/L
C) 1.6 mEq/L
D) 2.2 mEq/L
Correct Answer: 2.2 mEq/L
, Rationale: Therapeutic lithium levels are 0.6-1.2 mEq/L; levels above 1.5 mEq/L indicate toxicity. A level
of 2.2 mEq/L is toxic and can cause severe neurological and cardiac complications. Maintenance levels
and regular monitoring are critical.
6. The nurse is assessing a patient who is taking digoxin. Which finding would prompt the nurse to
withhold the medication and notify the provider?
A) Blood pressure 130/80 mmHg
B) Apical pulse 56 beats per minute
C) Serum potassium 4.2 mEq/L
D) Respiratory rate 18 breaths per minute
Correct Answer: Apical pulse 56 beats per minute
Rationale: Digoxin can cause bradycardia; the nurse should hold the dose if the apical pulse is below 60
bpm in adults (or per specific order). Blood pressure, normal potassium, and respiratory rate are not
reasons to withhold. Bradycardia may indicate digoxin toxicity.
7. A patient is prescribed metformin for type 2 diabetes. Which condition should the nurse identify as a
contraindication?
A) Obesity
B) Hyperlipidemia
C) Renal impairment with creatinine clearance below 30 mL/min
D) Hypertension
Correct Answer: Renal impairment with creatinine clearance below 30 mL/min
Rationale: Metformin is contraindicated in significant renal impairment because of the risk of lactic
acidosis, a rare but life-threatening complication. It is not contraindicated with obesity, hyperlipidemia,
or hypertension alone, though caution is used with hepatic disease.
