NR565 Advanced Pharmacology Week 4 Midterm
Exam - 150 Practice Questions with Answers
PHARMACOKINETICS & PHARMACODYNAMICS
Domain 1: Drug Absorption and Ionization
Q1: A drug that is a weak acid with a pKa of 4.4 will be mostly non-ionized and well-
absorbed in which part of the gastrointestinal tract?
A) Small intestine (pH 7.4)
B) Stomach (pH 1.5–3.5)
C) Colon (pH 5.5–7.0)
D) Blood (pH 7.35)
Correct Answer: B) Stomach (pH 1.5–3.5)
Rationale: Weak acids are predominantly non-ionized in acidic environments (low pH)
according to the Henderson-Hasselbalch equation. The stomach's low pH favors non-
ionization of weak acids, allowing passive diffusion across the gastric mucosa. Weak bases
are better absorbed in the small intestine (pH ~7.4) .
Q2: A patient is prescribed a drug that is a weak base with a pKa of 8.4. In which part of
the body will this drug be most highly ionized?
A) Small intestine (pH 7.4)
B) Stomach (pH 1.5–3.5)
C) Blood (pH 7.35–7.45)
D) Urine (pH 5.0–8.0)
Correct Answer: B) Stomach (pH 1.5–3.5)
Rationale: Weak bases are more ionized in acidic environments (low pH). Ionized drugs are
poorly absorbed across lipid membranes. Weak acids are better absorbed in the stomach;
weak bases are better absorbed in the small intestine .
Q3: Which statement best describes the therapeutic index (TI)?
A) The ratio of the dose required to produce a toxic effect to the dose required to produce a
therapeutic effect
B) The time required for drug concentration to drop by 50%
C) The fraction of drug that reaches systemic circulation unchanged
D) The rate at which a drug is removed from the body
Correct Answer: A) The ratio of the dose required to produce a toxic effect to the dose
required to produce a therapeutic effect
,Rationale: The therapeutic index = TD50 (toxic dose in 50% of population) / ED50 (effective
dose in 50% of population). A narrow TI (e.g., warfarin, digoxin, phenytoin) indicates a small
margin between efficacy and toxicity, requiring careful dose titration and serum level
monitoring .
Q4: A drug with a narrow therapeutic index (e.g., lithium, warfarin) requires:
A) Less frequent monitoring
B) More frequent monitoring of serum drug levels
C) Administration with food only
D) Use only in pediatric patients
Correct Answer: B) More frequent monitoring of serum drug levels
Rationale: Drugs with a narrow therapeutic index have a small margin between therapeutic
and toxic doses. Frequent monitoring of serum levels is required to ensure the dose remains
within the safe and effective window .
Q5: A patient with severe liver cirrhosis is prescribed a medication with high first-pass
metabolism. The nurse practitioner should expect:
A) Reduced bioavailability and need for higher oral doses
B) Increased bioavailability and increased risk of toxicity
C) No change in drug response
D) Faster elimination of the drug
Correct Answer: B) Increased bioavailability and increased risk of toxicity
Rationale: First-pass metabolism occurs in the liver. In severe cirrhosis, hepatocyte function
and portal blood flow are reduced, diminishing first-pass extraction. This results in a higher
fraction of the oral dose reaching systemic circulation (increased bioavailability), which can
lead to supratherapeutic effects and toxicity .
Q6: Which pharmacokinetic process is most affected by first-pass metabolism?
A) Distribution
B) Metabolism
C) Oral absorption
D) Renal excretion
Correct Answer: C) Oral absorption
Rationale: First-pass metabolism occurs in the liver and gut wall after oral administration,
reducing the amount of active drug reaching systemic circulation. Drugs with extensive first-
pass effect often require higher oral doses or alternative routes (IV, sublingual,
transdermal) .
Q7: A medication with a half-life of 24 hours is administered once daily. Approximately
how many days will it take to reach steady-state concentration?
,A) 2 days
B) 3 days
C) 5 days
D) 10 days
Correct Answer: C) 5 days
Rationale: Steady-state is achieved after approximately 4–5 half-lives of continuous dosing.
With a 24-hour half-life, steady-state will be reached in 4–5 days .
Q8: The time required for half of a drug concentration to be eliminated from the body is
called:
A) Peak level
B) Bioavailability
C) Half-life
D) Potency
Correct Answer: C) Half-life
Rationale: Half-life determines dosing intervals and duration of action. It is the time required
for the drug concentration in the body to be reduced by 50% .
Q9: The primary purpose of a loading dose is to:
A) Maintain steady-state concentration over a long period
B) Achieve therapeutic concentration rapidly
C) Reduce the risk of adverse effects
D) Prolong the half-life of the drug
Correct Answer: B) Achieve therapeutic concentration rapidly
Rationale: A loading dose is a larger initial dose given to rapidly achieve therapeutic plasma
concentrations before steady-state is reached with maintenance dosing. It is used for drugs
with long half-lives (e.g., amiodarone, digoxin, phenytoin) when immediate effect is needed .
Q10: What does bioavailability refer to?
A) The amount of drug that reaches systemic circulation unchanged
B) The rate at which drug is metabolized
C) The time it takes for drug to be eliminated
D) The volume of distribution
Correct Answer: A) The amount of drug that reaches systemic circulation unchanged
Rationale: Bioavailability (F) is the fraction of the administered dose that reaches systemic
circulation unchanged. IV drugs have 100% bioavailability; oral drugs have variable
bioavailability due to incomplete absorption and first-pass metabolism .
, Domain 2: Drug Distribution and Protein Binding
Q11: A patient is prescribed a drug that is 95% protein-bound. Which condition would
most likely increase the free (active) fraction of this drug?
A) Hypoalbuminemia (e.g., malnutrition, nephrotic syndrome)
B) Obesity
C) Young age
D) Concurrent administration of a drug with low protein binding
Correct Answer: A) Hypoalbuminemia (e.g., malnutrition, nephrotic syndrome)
Rationale: Drugs bind primarily to albumin. Hypoalbuminemia reduces available binding
sites, increasing the free (unbound) fraction of highly protein-bound drugs (e.g., phenytoin,
warfarin). This can lead to toxicity even with normal total drug concentrations, as only free
drug is pharmacologically active .
Q12: A 70-year-old patient with heart failure is started on a new medication with high
protein-binding affinity. Which pharmacokinetic change related to aging most increases
the risk of toxicity?
A) Increased glomerular filtration rate
B) Decreased alpha-1-acid glycoprotein levels leading to increased free drug fraction
C) Increased hepatic first-pass effect
D) Decreased adipose tissue distribution
Correct Answer: B) Decreased alpha-1-acid glycoprotein levels leading to increased free
drug fraction
Rationale: Age-related decrease in serum albumin and alpha-1-acid glycoprotein increases
free drug concentration for highly protein-bound drugs, risking toxicity. Free drug is
pharmacologically active .
Q13: Which factors contribute to age-related changes in drug distribution? (Select all that
apply)
A) Increased body fat
B) Decreased lean body mass
C) Decreased total body water
D) Decreased serum albumin
E) Decreased cardiac output
Correct Answer: A, B, C, D, E
Rationale: All five factors are correct: aging increases body fat (lipophilic drug reservoir),
decreases lean body mass, decreases total body water (affects hydrophilic drug distribution),
decreases serum albumin (increases free drug fraction for protein-bound drugs), and
decreases cardiac output (slows drug delivery to tissues) .
Q14: What is the clinical significance of enterohepatic recirculation?
Exam - 150 Practice Questions with Answers
PHARMACOKINETICS & PHARMACODYNAMICS
Domain 1: Drug Absorption and Ionization
Q1: A drug that is a weak acid with a pKa of 4.4 will be mostly non-ionized and well-
absorbed in which part of the gastrointestinal tract?
A) Small intestine (pH 7.4)
B) Stomach (pH 1.5–3.5)
C) Colon (pH 5.5–7.0)
D) Blood (pH 7.35)
Correct Answer: B) Stomach (pH 1.5–3.5)
Rationale: Weak acids are predominantly non-ionized in acidic environments (low pH)
according to the Henderson-Hasselbalch equation. The stomach's low pH favors non-
ionization of weak acids, allowing passive diffusion across the gastric mucosa. Weak bases
are better absorbed in the small intestine (pH ~7.4) .
Q2: A patient is prescribed a drug that is a weak base with a pKa of 8.4. In which part of
the body will this drug be most highly ionized?
A) Small intestine (pH 7.4)
B) Stomach (pH 1.5–3.5)
C) Blood (pH 7.35–7.45)
D) Urine (pH 5.0–8.0)
Correct Answer: B) Stomach (pH 1.5–3.5)
Rationale: Weak bases are more ionized in acidic environments (low pH). Ionized drugs are
poorly absorbed across lipid membranes. Weak acids are better absorbed in the stomach;
weak bases are better absorbed in the small intestine .
Q3: Which statement best describes the therapeutic index (TI)?
A) The ratio of the dose required to produce a toxic effect to the dose required to produce a
therapeutic effect
B) The time required for drug concentration to drop by 50%
C) The fraction of drug that reaches systemic circulation unchanged
D) The rate at which a drug is removed from the body
Correct Answer: A) The ratio of the dose required to produce a toxic effect to the dose
required to produce a therapeutic effect
,Rationale: The therapeutic index = TD50 (toxic dose in 50% of population) / ED50 (effective
dose in 50% of population). A narrow TI (e.g., warfarin, digoxin, phenytoin) indicates a small
margin between efficacy and toxicity, requiring careful dose titration and serum level
monitoring .
Q4: A drug with a narrow therapeutic index (e.g., lithium, warfarin) requires:
A) Less frequent monitoring
B) More frequent monitoring of serum drug levels
C) Administration with food only
D) Use only in pediatric patients
Correct Answer: B) More frequent monitoring of serum drug levels
Rationale: Drugs with a narrow therapeutic index have a small margin between therapeutic
and toxic doses. Frequent monitoring of serum levels is required to ensure the dose remains
within the safe and effective window .
Q5: A patient with severe liver cirrhosis is prescribed a medication with high first-pass
metabolism. The nurse practitioner should expect:
A) Reduced bioavailability and need for higher oral doses
B) Increased bioavailability and increased risk of toxicity
C) No change in drug response
D) Faster elimination of the drug
Correct Answer: B) Increased bioavailability and increased risk of toxicity
Rationale: First-pass metabolism occurs in the liver. In severe cirrhosis, hepatocyte function
and portal blood flow are reduced, diminishing first-pass extraction. This results in a higher
fraction of the oral dose reaching systemic circulation (increased bioavailability), which can
lead to supratherapeutic effects and toxicity .
Q6: Which pharmacokinetic process is most affected by first-pass metabolism?
A) Distribution
B) Metabolism
C) Oral absorption
D) Renal excretion
Correct Answer: C) Oral absorption
Rationale: First-pass metabolism occurs in the liver and gut wall after oral administration,
reducing the amount of active drug reaching systemic circulation. Drugs with extensive first-
pass effect often require higher oral doses or alternative routes (IV, sublingual,
transdermal) .
Q7: A medication with a half-life of 24 hours is administered once daily. Approximately
how many days will it take to reach steady-state concentration?
,A) 2 days
B) 3 days
C) 5 days
D) 10 days
Correct Answer: C) 5 days
Rationale: Steady-state is achieved after approximately 4–5 half-lives of continuous dosing.
With a 24-hour half-life, steady-state will be reached in 4–5 days .
Q8: The time required for half of a drug concentration to be eliminated from the body is
called:
A) Peak level
B) Bioavailability
C) Half-life
D) Potency
Correct Answer: C) Half-life
Rationale: Half-life determines dosing intervals and duration of action. It is the time required
for the drug concentration in the body to be reduced by 50% .
Q9: The primary purpose of a loading dose is to:
A) Maintain steady-state concentration over a long period
B) Achieve therapeutic concentration rapidly
C) Reduce the risk of adverse effects
D) Prolong the half-life of the drug
Correct Answer: B) Achieve therapeutic concentration rapidly
Rationale: A loading dose is a larger initial dose given to rapidly achieve therapeutic plasma
concentrations before steady-state is reached with maintenance dosing. It is used for drugs
with long half-lives (e.g., amiodarone, digoxin, phenytoin) when immediate effect is needed .
Q10: What does bioavailability refer to?
A) The amount of drug that reaches systemic circulation unchanged
B) The rate at which drug is metabolized
C) The time it takes for drug to be eliminated
D) The volume of distribution
Correct Answer: A) The amount of drug that reaches systemic circulation unchanged
Rationale: Bioavailability (F) is the fraction of the administered dose that reaches systemic
circulation unchanged. IV drugs have 100% bioavailability; oral drugs have variable
bioavailability due to incomplete absorption and first-pass metabolism .
, Domain 2: Drug Distribution and Protein Binding
Q11: A patient is prescribed a drug that is 95% protein-bound. Which condition would
most likely increase the free (active) fraction of this drug?
A) Hypoalbuminemia (e.g., malnutrition, nephrotic syndrome)
B) Obesity
C) Young age
D) Concurrent administration of a drug with low protein binding
Correct Answer: A) Hypoalbuminemia (e.g., malnutrition, nephrotic syndrome)
Rationale: Drugs bind primarily to albumin. Hypoalbuminemia reduces available binding
sites, increasing the free (unbound) fraction of highly protein-bound drugs (e.g., phenytoin,
warfarin). This can lead to toxicity even with normal total drug concentrations, as only free
drug is pharmacologically active .
Q12: A 70-year-old patient with heart failure is started on a new medication with high
protein-binding affinity. Which pharmacokinetic change related to aging most increases
the risk of toxicity?
A) Increased glomerular filtration rate
B) Decreased alpha-1-acid glycoprotein levels leading to increased free drug fraction
C) Increased hepatic first-pass effect
D) Decreased adipose tissue distribution
Correct Answer: B) Decreased alpha-1-acid glycoprotein levels leading to increased free
drug fraction
Rationale: Age-related decrease in serum albumin and alpha-1-acid glycoprotein increases
free drug concentration for highly protein-bound drugs, risking toxicity. Free drug is
pharmacologically active .
Q13: Which factors contribute to age-related changes in drug distribution? (Select all that
apply)
A) Increased body fat
B) Decreased lean body mass
C) Decreased total body water
D) Decreased serum albumin
E) Decreased cardiac output
Correct Answer: A, B, C, D, E
Rationale: All five factors are correct: aging increases body fat (lipophilic drug reservoir),
decreases lean body mass, decreases total body water (affects hydrophilic drug distribution),
decreases serum albumin (increases free drug fraction for protein-bound drugs), and
decreases cardiac output (slows drug delivery to tissues) .
Q14: What is the clinical significance of enterohepatic recirculation?
