NR 565 Final Exam Chamberlain Advanced
Pharmacology 2026
1. Which pharmacokinetic parameter is defined as the proportion of an
administered drug that reaches systemic circulation in an unchanged form?
A. Bioavailability
B. Therapeutic index
C. Half-life
D. Clearance
*Answer: A. Bioavailability. *
Rationale: Bioavailability (F) specifically measures the fraction of the administered drug
that enters systemic circulation unchanged. It is a key determinant of drug efficacy for oral
medications. The therapeutic index is a safety ratio, half-life is elimination time, and
clearance is the volume of blood cleared of drug per unit time.
2. A 65-year-old male with cirrhosis is prescribed a medication that undergoes
extensive first-pass hepatic metabolism. The nurse practitioner understands that
the bioavailability of this medication will be significantly affected by which
pharmacokinetic alteration?
A. Decreased absorption from the GI tract
B. Reduced first-pass metabolism leading to increased bioavailability
C. Enhanced renal elimination compensating for hepatic impairment
D. Increased protein binding reducing free drug concentration
*Answer: B. Reduced first-pass metabolism leading to increased bioavailability. *
Rationale: In cirrhosis, first-pass hepatic metabolism is reduced due to damaged
hepatocytes and portosystemic shunting, leading to increased bioavailability of drugs that
, normally undergo extensive first-pass metabolism. This requires dose reduction to avoid
toxicity.
3. A 42-year-old female is taking warfarin 5 mg daily for atrial fibrillation. She is
newly prescribed amiodarone for rate control. The nurse practitioner recognizes
that this drug interaction is mediated through which mechanism?
A. Amiodarone increases warfarin metabolism via CYP450 induction
B. Amiodarone inhibits warfarin metabolism via CYP2C9 inhibition
C. Amiodarone displaces warfarin from plasma protein binding sites
D. Amiodarone reduces warfarin absorption from the GI tract
*Answer: B. Amiodarone inhibits warfarin metabolism via CYP2C9 inhibition. *
Rationale: Amiodarone is a potent CYP2C9 inhibitor that reduces warfarin metabolism,
leading to increased INR and bleeding risk. The warfarin dose typically needs to be
reduced by 30-50% when amiodarone is initiated.
4. A nurse practitioner is prescribing a drug with a narrow therapeutic index. The
NP understands that therapeutic drug monitoring is most important for which
reason?
A. To ensure the drug remains below the minimum effective concentration
B. To maintain drug levels within the narrow range between efficacy and toxicity
C. To confirm patient adherence to the prescribed regimen
D. To reduce the cost of therapy by minimizing drug waste
*Answer: B. To maintain drug levels within the narrow range between efficacy and
toxicity. *
Rationale: Drugs with narrow therapeutic indices require monitoring to maintain serum
levels within the narrow window between therapeutic efficacy and toxicity. Examples
include warfarin, digoxin, and lithium.
, 5. A 70-year-old male with reduced creatinine clearance of 35 mL/min is
prescribed gentamicin for a serious infection. The NP adjusts the dosing interval
rather than the dose. This adjustment is based on which pharmacokinetic
principle?
A. Reduced renal clearance increases the volume of distribution
B. Decreased renal elimination prolongs the drug half-life requiring longer intervals
C. Renal impairment increases drug absorption from the GI tract
D. Reduced kidney function enhances hepatic metabolism of aminoglycosides
*Answer: B. Decreased renal elimination prolongs the drug half-life requiring
longer intervals. *
Rationale: In renal impairment, gentamicin elimination is reduced, prolonging the half-life.
Extending the dosing interval allows more time for drug elimination between doses,
preventing accumulation and toxicity while maintaining peak concentrations for efficacy.
6. A 55-year-old patient is taking phenytoin for seizure control. The patient
presents with nystagmus and ataxia. The NP suspects phenytoin toxicity. What is
the most likely cause of this toxicity?
A. Decreased protein binding
B. Saturation of metabolic pathways
C. Increased renal clearance
D. Enhanced GI absorption
*Answer: B. Saturation of metabolic pathways. *
Rationale: Phenytoin exhibits nonlinear pharmacokinetics due to saturation of hepatic
metabolic enzymes at therapeutic concentrations. Small increases in dose can lead to
large increases in serum concentration, causing toxicity. Signs of toxicity include
nystagmus, ataxia, and diplopia.
7. What occurs during Phase 1 metabolism of drugs via CYP450?
A. Drugs are conjugated to increase water solubility
, B. Drugs are oxidized, reduced, or hydrolyzed
C. Drugs are excreted unchanged
D. Drugs are bound to plasma proteins
*Answer: B. Drugs are oxidized, reduced, or hydrolyzed. *
Rationale: Phase 1 metabolism involves oxidation, reduction, or hydrolysis reactions,
typically mediated by the CYP450 enzyme system. These reactions prepare drugs for Phase
2 conjugation reactions.
8. What occurs during Phase 2 metabolism of drugs?
A. Oxidation and reduction reactions
B. Conjugation reactions (e.g., glucuronidation, sulfation)
C. Drug absorption from the GI tract
D. Drug distribution to tissues
*Answer: B. Conjugation reactions (e.g., glucuronidation, sulfation). *
Rationale: Phase 2 metabolism involves conjugation reactions that increase water
solubility, facilitating renal excretion. Examples include glucuronidation, sulfation, and
acetylation.
9. A medication with a narrow therapeutic index requires careful monitoring
because:
A. It is rapidly absorbed
B. Toxicity can occur with small dosage changes
C. It has a long half-life
D. It is poorly distributed
*Answer: B. Toxicity can occur with small dosage changes. *
Rationale: Narrow therapeutic index drugs have a small margin between therapeutic and
toxic doses. Examples include warfarin, digoxin, and lithium. Even small dosage changes
can lead to toxicity or subtherapeutic effects.
Pharmacology 2026
1. Which pharmacokinetic parameter is defined as the proportion of an
administered drug that reaches systemic circulation in an unchanged form?
A. Bioavailability
B. Therapeutic index
C. Half-life
D. Clearance
*Answer: A. Bioavailability. *
Rationale: Bioavailability (F) specifically measures the fraction of the administered drug
that enters systemic circulation unchanged. It is a key determinant of drug efficacy for oral
medications. The therapeutic index is a safety ratio, half-life is elimination time, and
clearance is the volume of blood cleared of drug per unit time.
2. A 65-year-old male with cirrhosis is prescribed a medication that undergoes
extensive first-pass hepatic metabolism. The nurse practitioner understands that
the bioavailability of this medication will be significantly affected by which
pharmacokinetic alteration?
A. Decreased absorption from the GI tract
B. Reduced first-pass metabolism leading to increased bioavailability
C. Enhanced renal elimination compensating for hepatic impairment
D. Increased protein binding reducing free drug concentration
*Answer: B. Reduced first-pass metabolism leading to increased bioavailability. *
Rationale: In cirrhosis, first-pass hepatic metabolism is reduced due to damaged
hepatocytes and portosystemic shunting, leading to increased bioavailability of drugs that
, normally undergo extensive first-pass metabolism. This requires dose reduction to avoid
toxicity.
3. A 42-year-old female is taking warfarin 5 mg daily for atrial fibrillation. She is
newly prescribed amiodarone for rate control. The nurse practitioner recognizes
that this drug interaction is mediated through which mechanism?
A. Amiodarone increases warfarin metabolism via CYP450 induction
B. Amiodarone inhibits warfarin metabolism via CYP2C9 inhibition
C. Amiodarone displaces warfarin from plasma protein binding sites
D. Amiodarone reduces warfarin absorption from the GI tract
*Answer: B. Amiodarone inhibits warfarin metabolism via CYP2C9 inhibition. *
Rationale: Amiodarone is a potent CYP2C9 inhibitor that reduces warfarin metabolism,
leading to increased INR and bleeding risk. The warfarin dose typically needs to be
reduced by 30-50% when amiodarone is initiated.
4. A nurse practitioner is prescribing a drug with a narrow therapeutic index. The
NP understands that therapeutic drug monitoring is most important for which
reason?
A. To ensure the drug remains below the minimum effective concentration
B. To maintain drug levels within the narrow range between efficacy and toxicity
C. To confirm patient adherence to the prescribed regimen
D. To reduce the cost of therapy by minimizing drug waste
*Answer: B. To maintain drug levels within the narrow range between efficacy and
toxicity. *
Rationale: Drugs with narrow therapeutic indices require monitoring to maintain serum
levels within the narrow window between therapeutic efficacy and toxicity. Examples
include warfarin, digoxin, and lithium.
, 5. A 70-year-old male with reduced creatinine clearance of 35 mL/min is
prescribed gentamicin for a serious infection. The NP adjusts the dosing interval
rather than the dose. This adjustment is based on which pharmacokinetic
principle?
A. Reduced renal clearance increases the volume of distribution
B. Decreased renal elimination prolongs the drug half-life requiring longer intervals
C. Renal impairment increases drug absorption from the GI tract
D. Reduced kidney function enhances hepatic metabolism of aminoglycosides
*Answer: B. Decreased renal elimination prolongs the drug half-life requiring
longer intervals. *
Rationale: In renal impairment, gentamicin elimination is reduced, prolonging the half-life.
Extending the dosing interval allows more time for drug elimination between doses,
preventing accumulation and toxicity while maintaining peak concentrations for efficacy.
6. A 55-year-old patient is taking phenytoin for seizure control. The patient
presents with nystagmus and ataxia. The NP suspects phenytoin toxicity. What is
the most likely cause of this toxicity?
A. Decreased protein binding
B. Saturation of metabolic pathways
C. Increased renal clearance
D. Enhanced GI absorption
*Answer: B. Saturation of metabolic pathways. *
Rationale: Phenytoin exhibits nonlinear pharmacokinetics due to saturation of hepatic
metabolic enzymes at therapeutic concentrations. Small increases in dose can lead to
large increases in serum concentration, causing toxicity. Signs of toxicity include
nystagmus, ataxia, and diplopia.
7. What occurs during Phase 1 metabolism of drugs via CYP450?
A. Drugs are conjugated to increase water solubility
, B. Drugs are oxidized, reduced, or hydrolyzed
C. Drugs are excreted unchanged
D. Drugs are bound to plasma proteins
*Answer: B. Drugs are oxidized, reduced, or hydrolyzed. *
Rationale: Phase 1 metabolism involves oxidation, reduction, or hydrolysis reactions,
typically mediated by the CYP450 enzyme system. These reactions prepare drugs for Phase
2 conjugation reactions.
8. What occurs during Phase 2 metabolism of drugs?
A. Oxidation and reduction reactions
B. Conjugation reactions (e.g., glucuronidation, sulfation)
C. Drug absorption from the GI tract
D. Drug distribution to tissues
*Answer: B. Conjugation reactions (e.g., glucuronidation, sulfation). *
Rationale: Phase 2 metabolism involves conjugation reactions that increase water
solubility, facilitating renal excretion. Examples include glucuronidation, sulfation, and
acetylation.
9. A medication with a narrow therapeutic index requires careful monitoring
because:
A. It is rapidly absorbed
B. Toxicity can occur with small dosage changes
C. It has a long half-life
D. It is poorly distributed
*Answer: B. Toxicity can occur with small dosage changes. *
Rationale: Narrow therapeutic index drugs have a small margin between therapeutic and
toxic doses. Examples include warfarin, digoxin, and lithium. Even small dosage changes
can lead to toxicity or subtherapeutic effects.
