NR 565 Advanced Pharmacology
Chamberlain University (Midterm) Study
Guide & Practice Questions with Answers
latest update
SECTION I: PHARMACOKINETICS & PHARMACODYNAMICS
1. A 72-year-old patient with heart failure and reduced ejection fraction is
prescribed a drug that undergoes extensive first-pass hepatic metabolism. The
nurse practitioner understands that which of the following pharmacokinetic
alterations is MOST likely to occur in this patient?
A. Enhanced first-pass metabolism due to hepatic congestion
B. Reduced first-pass metabolism leading to increased bioavailability
C. Decreased gastrointestinal absorption due to bowel edema
D. Increased renal elimination compensating for hepatic impairment
Correct Answer: B
Rationale: In heart failure with hepatic congestion, first-pass metabolism
is reduced due to impaired hepatic blood flow and hepatocyte function. This leads
to increased bioavailability of drugs that normally undergo extensive first-pass
metabolism, requiring potential dose reduction to avoid toxicity. Option A is
incorrect because hepatic congestion impairs, rather than enhances, metabolism.
Option C is possible but not the primary mechanism described. Option D is
incorrect because renal elimination is often impaired, not increased, in heart
failure.
2. Which of the following statements BEST describes the difference between
pharmacokinetics and pharmacodynamics?
,A. Pharmacokinetics studies drug effects on the body; pharmacodynamics studies
drug movement.
B. Pharmacokinetics studies drug absorption, distribution, metabolism, and
excretion; pharmacodynamics studies drug effects on the body.
C. Pharmacokinetics studies receptor binding; pharmacodynamics studies drug
metabolism.
D. Pharmacokinetics studies toxic effects; pharmacodynamics studies therapeutic
effects.
Correct Answer: B
Rationale: Pharmacokinetics (PK) describes what the body does to the
drug — absorption, distribution, metabolism, and excretion (ADME).
Pharmacodynamics (PD) describes what the drug does to the body — the
biochemical and physiologic effects and mechanisms of action. Options A, C, and
D incorrectly reverse or mischaracterize these definitions.
3. A drug is a weak acid with a pKa of 4.5. In a patient with acidic urine (pH 5.0),
which of the following BEST describes the drug's ionization state and renal
excretion?
A. The drug will be primarily ionized and rapidly excreted.
B. The drug will be primarily unionized and reabsorbed.
C. The drug will be primarily ionized and reabsorbed.
D. The drug will be primarily unionized and excreted.
Correct Answer: B
Rationale: Weak acids are more unionized in acidic environments (pH <
pKa). Unionized drugs are lipid-soluble and are readily reabsorbed across renal
tubular membranes, leading to prolonged action and decreased excretion. In
alkaline urine, weak acids become ionized and are trapped in the tubule for
excretion. This principle underlies urinary alkalinization for salicylate overdose.
,4. A nurse practitioner is reviewing the concept of therapeutic index (TI). Which of
the following drugs is MOST likely to require careful monitoring due to a narrow
therapeutic index?
A. Amoxicillin
B. Digoxin
C. Loratadine
D. Acetaminophen
Correct Answer: B
Rationale: Digoxin has a narrow therapeutic index, meaning there is a
small margin between therapeutic and toxic doses. Drugs with narrow TIs require
therapeutic drug monitoring to prevent toxicity. Amoxicillin, loratadine, and
acetaminophen (at therapeutic doses) have wider safety margins.
5. Which cytochrome P450 enzyme is responsible for the metabolism of the
LARGEST number of clinically used drugs?
A. CYP1A2
B. CYP2D6
C. CYP3A4
D. CYP2C9
Correct Answer: C
Rationale: CYP3A4 is the most abundant CYP450 enzyme in the liver and
intestinal wall and is responsible for the metabolism of approximately 50% of
clinically used drugs, including many statins, calcium channel blockers,
benzodiazepines, and immunosuppressants. CYP2D6 is involved in ~25%, and
CYP2C9 and CYP1A2 are also important but less broadly involved.
6. A patient taking warfarin is prescribed a medication that is a potent CYP2C9
inhibitor. The nurse practitioner should anticipate which of the following?
A. Decreased warfarin effect due to enhanced metabolism.
B. Increased warfarin effect due to inhibited metabolism.
, C. No change in warfarin effect because CYP2C9 is not involved.
D. Increased warfarin effect due to enhanced protein binding.
Correct Answer: B
Rationale: Warfarin is metabolized primarily by CYP2C9. Inhibiting this
enzyme decreases warfarin metabolism, leading to increased plasma levels and
enhanced anticoagulant effect, increasing bleeding risk. This requires close INR
monitoring and potential dose reduction. Option A is incorrect because inhibition
decreases metabolism. Option C is incorrect because CYP2C9 is a major metabolic
pathway for warfarin. Option D is incorrect because protein binding displacement
is not the mechanism here.
7. Which of the following BEST defines pharmacogenomics?
A. The study of how drugs affect gene expression.
B. The study of how genes affect a person's response to drugs.
C. The study of drug interactions with genetic material.
D. The study of inherited drug allergies.
Correct Answer: B
Rationale: Pharmacogenomics combines genomics and pharmacology to
study how genetic variations influence individual drug responses, including
efficacy and toxicity. This enables personalized, targeted drug therapy. Option A
describes pharmacogenetics in reverse (drug effects on genes), and options C and
D are not accurate definitions.
8. A 68-year-old patient is prescribed a drug that is highly protein-bound (98%).
The patient has hypoalbuminemia due to cirrhosis. What is the MOST likely
clinical consequence?
A. Decreased free drug concentration and reduced effect.
B. Increased free drug concentration and enhanced effect.
C. No change because protein binding is not clinically relevant.
D. Decreased total drug concentration with no change in free drug.
Chamberlain University (Midterm) Study
Guide & Practice Questions with Answers
latest update
SECTION I: PHARMACOKINETICS & PHARMACODYNAMICS
1. A 72-year-old patient with heart failure and reduced ejection fraction is
prescribed a drug that undergoes extensive first-pass hepatic metabolism. The
nurse practitioner understands that which of the following pharmacokinetic
alterations is MOST likely to occur in this patient?
A. Enhanced first-pass metabolism due to hepatic congestion
B. Reduced first-pass metabolism leading to increased bioavailability
C. Decreased gastrointestinal absorption due to bowel edema
D. Increased renal elimination compensating for hepatic impairment
Correct Answer: B
Rationale: In heart failure with hepatic congestion, first-pass metabolism
is reduced due to impaired hepatic blood flow and hepatocyte function. This leads
to increased bioavailability of drugs that normally undergo extensive first-pass
metabolism, requiring potential dose reduction to avoid toxicity. Option A is
incorrect because hepatic congestion impairs, rather than enhances, metabolism.
Option C is possible but not the primary mechanism described. Option D is
incorrect because renal elimination is often impaired, not increased, in heart
failure.
2. Which of the following statements BEST describes the difference between
pharmacokinetics and pharmacodynamics?
,A. Pharmacokinetics studies drug effects on the body; pharmacodynamics studies
drug movement.
B. Pharmacokinetics studies drug absorption, distribution, metabolism, and
excretion; pharmacodynamics studies drug effects on the body.
C. Pharmacokinetics studies receptor binding; pharmacodynamics studies drug
metabolism.
D. Pharmacokinetics studies toxic effects; pharmacodynamics studies therapeutic
effects.
Correct Answer: B
Rationale: Pharmacokinetics (PK) describes what the body does to the
drug — absorption, distribution, metabolism, and excretion (ADME).
Pharmacodynamics (PD) describes what the drug does to the body — the
biochemical and physiologic effects and mechanisms of action. Options A, C, and
D incorrectly reverse or mischaracterize these definitions.
3. A drug is a weak acid with a pKa of 4.5. In a patient with acidic urine (pH 5.0),
which of the following BEST describes the drug's ionization state and renal
excretion?
A. The drug will be primarily ionized and rapidly excreted.
B. The drug will be primarily unionized and reabsorbed.
C. The drug will be primarily ionized and reabsorbed.
D. The drug will be primarily unionized and excreted.
Correct Answer: B
Rationale: Weak acids are more unionized in acidic environments (pH <
pKa). Unionized drugs are lipid-soluble and are readily reabsorbed across renal
tubular membranes, leading to prolonged action and decreased excretion. In
alkaline urine, weak acids become ionized and are trapped in the tubule for
excretion. This principle underlies urinary alkalinization for salicylate overdose.
,4. A nurse practitioner is reviewing the concept of therapeutic index (TI). Which of
the following drugs is MOST likely to require careful monitoring due to a narrow
therapeutic index?
A. Amoxicillin
B. Digoxin
C. Loratadine
D. Acetaminophen
Correct Answer: B
Rationale: Digoxin has a narrow therapeutic index, meaning there is a
small margin between therapeutic and toxic doses. Drugs with narrow TIs require
therapeutic drug monitoring to prevent toxicity. Amoxicillin, loratadine, and
acetaminophen (at therapeutic doses) have wider safety margins.
5. Which cytochrome P450 enzyme is responsible for the metabolism of the
LARGEST number of clinically used drugs?
A. CYP1A2
B. CYP2D6
C. CYP3A4
D. CYP2C9
Correct Answer: C
Rationale: CYP3A4 is the most abundant CYP450 enzyme in the liver and
intestinal wall and is responsible for the metabolism of approximately 50% of
clinically used drugs, including many statins, calcium channel blockers,
benzodiazepines, and immunosuppressants. CYP2D6 is involved in ~25%, and
CYP2C9 and CYP1A2 are also important but less broadly involved.
6. A patient taking warfarin is prescribed a medication that is a potent CYP2C9
inhibitor. The nurse practitioner should anticipate which of the following?
A. Decreased warfarin effect due to enhanced metabolism.
B. Increased warfarin effect due to inhibited metabolism.
, C. No change in warfarin effect because CYP2C9 is not involved.
D. Increased warfarin effect due to enhanced protein binding.
Correct Answer: B
Rationale: Warfarin is metabolized primarily by CYP2C9. Inhibiting this
enzyme decreases warfarin metabolism, leading to increased plasma levels and
enhanced anticoagulant effect, increasing bleeding risk. This requires close INR
monitoring and potential dose reduction. Option A is incorrect because inhibition
decreases metabolism. Option C is incorrect because CYP2C9 is a major metabolic
pathway for warfarin. Option D is incorrect because protein binding displacement
is not the mechanism here.
7. Which of the following BEST defines pharmacogenomics?
A. The study of how drugs affect gene expression.
B. The study of how genes affect a person's response to drugs.
C. The study of drug interactions with genetic material.
D. The study of inherited drug allergies.
Correct Answer: B
Rationale: Pharmacogenomics combines genomics and pharmacology to
study how genetic variations influence individual drug responses, including
efficacy and toxicity. This enables personalized, targeted drug therapy. Option A
describes pharmacogenetics in reverse (drug effects on genes), and options C and
D are not accurate definitions.
8. A 68-year-old patient is prescribed a drug that is highly protein-bound (98%).
The patient has hypoalbuminemia due to cirrhosis. What is the MOST likely
clinical consequence?
A. Decreased free drug concentration and reduced effect.
B. Increased free drug concentration and enhanced effect.
C. No change because protein binding is not clinically relevant.
D. Decreased total drug concentration with no change in free drug.
