UST ABSN PATHOPHARMACOLOGY 1 ACTUAL EXAM
2026/2027 | Updated Correct Answers | Pass Guaranteed - A+
Graded
SECTION 1: Fundamentals of Pathophysiology & Pharmacology (Q1-Q15)
Q1: A nurse is reviewing pharmacokinetics with a nursing student. The student asks
which organ is primarily responsible for the metabolism of most drugs. Which response
by the nurse is correct?
A. Kidneys are the primary site of drug metabolism.
B. The liver is the primary site of drug metabolism via cytochrome P450 enzymes.
[CORRECT]
C. The lungs metabolize the majority of drugs through first-pass effects.
D. The skin is responsible for biotransformation of lipophilic drugs.
Correct Answer: B
Rationale: The liver is the primary organ for drug metabolism, predominantly through the
cytochrome P450 enzyme system. While kidneys are the main organ for excretion, they
play a minimal role in biotransformation compared to hepatic enzymes.
Q2: A patient asks why their oral nitroglycerin tablet is ineffective for relieving chest
pain. The nurse explains that this is primarily due to which pharmacokinetic process?
A. Enterohepatic recycling prevents oral nitroglycerin from reaching therapeutic levels.
B. The first-pass effect extensively metabolizes nitroglycerin in the liver before it
reaches systemic circulation. [CORRECT]
C. Zero-order kinetics causes unpredictable plasma concentrations of oral nitroglycerin.
D. Redistribution of nitroglycerin into adipose tissue limits its cardiac effects.
Correct Answer: B
Rationale: Nitroglycerin undergoes extensive first-pass hepatic metabolism, rendering
oral administration ineffective; sublingual administration bypasses this effect by
entering systemic circulation directly. Enterohepatic recycling involves biliary excretion
and intestinal reabsorption, not first-pass metabolism.
,Q3: A 70-year-old patient with decreased serum albumin is prescribed a highly
protein-bound drug. The nurse anticipates which clinical effect?
A. Decreased drug effect due to reduced protein binding in plasma.
B. Increased free drug concentration and potential for toxicity. [CORRECT]
C. No change in drug distribution because albumin does not affect pharmacokinetics.
D. Increased drug metabolism due to enhanced hepatic blood flow.
Correct Answer: B
Rationale: Decreased albumin reduces protein binding, increasing the free (unbound,
pharmacologically active) fraction of highly protein-bound drugs, which can lead to
enhanced effects and toxicity. Free drug is the active form available to exert
pharmacologic effects and be metabolized.
Q4: A drug has a half-life of 6 hours. Approximately how long will it take to reach
steady-state concentration with continuous administration?
A. 6 hours, which represents one half-life.
B. 12 hours, which represents two half-lives.
C. 24 hours, which represents four half-lives.
D. 30 hours, which represents five half-lives. [CORRECT]
Correct Answer: D
Rationale: Steady-state concentration is typically reached after 4-5 half-lives; with a
6-hour half-life, this equals 24-30 hours. At steady state, the rate of drug administration
equals the rate of elimination, resulting in stable plasma concentrations.
Q5: A patient is prescribed a loading dose of 500 mg followed by a maintenance dose of
100 mg every 6 hours. The drug has a volume of distribution of 50 L. What is the
expected plasma concentration immediately after the loading dose?
A. 5 mcg/mL
B. 10 mcg/mL [CORRECT]
C. 15 mcg/mL
D. 20 mcg/mL
Correct Answer: B
Rationale: Concentration = Dose / Vd = 500 mg / 50 L = 10 mg/L = 10 mcg/mL. Loading
doses rapidly achieve therapeutic concentrations by filling the volume of distribution,
allowing immediate therapeutic effect before steady state is reached.
,Q6: A nurse is teaching a patient about pharmacodynamics. Which statement best
describes the mechanism of action of a drug agonist?
A. An agonist blocks receptor activation without producing a response.
B. An agonist binds to a receptor and produces a physiologic response. [CORRECT]
C. An agonist increases the metabolism of other drugs at hepatic enzyme sites.
D. An agonist prevents drug absorption in the gastrointestinal tract.
Correct Answer: B
Rationale: An agonist binds to receptors and activates them to produce a physiologic
response, whereas antagonists block receptor activation without producing a response.
Partial agonists produce submaximal responses even at full receptor occupancy.
Q7: A patient taking warfarin is started on a new medication that induces cytochrome
P450 enzymes. The nurse anticipates which clinical change?
A. Increased warfarin effect and elevated bleeding risk.
B. Decreased warfarin effect and potential for thromboembolic events. [CORRECT]
C. No change in warfarin plasma concentration or anticoagulant effect.
D. Increased warfarin absorption from the gastrointestinal tract.
Correct Answer: B
Rationale: CYP450 enzyme induction increases warfarin metabolism, decreasing its
plasma concentration and anticoagulant effect, potentially leading to thromboembolic
events. Enzyme inducers such as rifampin and carbamazepine accelerate drug
clearance and may necessitate warfarin dose increases.
Q8: A patient on warfarin with a therapeutic INR of 2.5 is prescribed
trimethoprim-sulfamethoxazole for a urinary tract infection. The nurse should monitor
closely for which potential interaction?
A. Decreased INR and risk of clot formation.
B. Increased INR and elevated bleeding risk. [CORRECT]
C. No clinically significant interaction exists between these medications.
D. Decreased effectiveness of the antibiotic due to warfarin binding.
Correct Answer: B
Rationale: TMP-SMX inhibits CYP2C9 metabolism of warfarin and displaces it from
protein binding sites, increasing INR and bleeding risk. Antibiotics also alter gut flora
that produce vitamin K, further potentiating warfarin's anticoagulant effect.
, Q9: A nurse is reviewing a drug's therapeutic index with a student nurse. Which
statement about therapeutic index is correct?
A. A narrow therapeutic index indicates a wide safety margin between effective and
toxic doses.
B. A drug with a narrow therapeutic index requires frequent therapeutic drug monitoring
to prevent toxicity. [CORRECT]
C. The therapeutic index is calculated as the ratio of ED50 to LD50.
D. Drugs with wide therapeutic indices never cause adverse effects or toxicity.
Correct Answer: B
Rationale: A narrow therapeutic index (small ratio of toxic to therapeutic dose) requires
frequent drug level monitoring to prevent toxicity, as seen with digoxin, lithium,
phenytoin, and warfarin. The therapeutic index is actually the ratio of TD50 to ED50 (or
LD50 to ED50 in animals).
Q10: A patient has been taking maximum daily doses of acetaminophen for 3 weeks for
chronic osteoarthritis pain. The nurse should monitor for which adverse effect?
A. Gastrointestinal bleeding and peptic ulcer disease.
B. Hepatotoxicity from accumulation of the toxic metabolite NAPQI. [CORRECT]
C. Nephrotoxicity manifesting as acute tubular necrosis.
D. Ototoxicity with tinnitus and hearing loss.
Correct Answer: B
Rationale: Chronic high-dose acetaminophen exhausts hepatic glutathione stores,
leading to hepatic necrosis via toxic NAPQI metabolite accumulation. Unlike NSAIDs,
acetaminophen does not typically cause GI bleeding, and it is not associated with
nephrotoxicity or ototoxicity at therapeutic doses.
Q11: Which phase of pharmacokinetics is primarily affected by hepatic blood flow,
protein binding, and enzyme activity?
A. Absorption is primarily affected by hepatic blood flow and protein binding.
B. Distribution depends mainly on hepatic blood flow and enzyme activity.
C. Metabolism is significantly influenced by hepatic blood flow and protein binding.
[CORRECT]
D. Excretion is primarily determined by hepatic blood flow and enzyme activity.
Correct Answer: C
Rationale: Hepatic metabolism depends on hepatic blood flow (delivering drug to the
liver), protein binding (only free drug is available for metabolism), and enzymatic
2026/2027 | Updated Correct Answers | Pass Guaranteed - A+
Graded
SECTION 1: Fundamentals of Pathophysiology & Pharmacology (Q1-Q15)
Q1: A nurse is reviewing pharmacokinetics with a nursing student. The student asks
which organ is primarily responsible for the metabolism of most drugs. Which response
by the nurse is correct?
A. Kidneys are the primary site of drug metabolism.
B. The liver is the primary site of drug metabolism via cytochrome P450 enzymes.
[CORRECT]
C. The lungs metabolize the majority of drugs through first-pass effects.
D. The skin is responsible for biotransformation of lipophilic drugs.
Correct Answer: B
Rationale: The liver is the primary organ for drug metabolism, predominantly through the
cytochrome P450 enzyme system. While kidneys are the main organ for excretion, they
play a minimal role in biotransformation compared to hepatic enzymes.
Q2: A patient asks why their oral nitroglycerin tablet is ineffective for relieving chest
pain. The nurse explains that this is primarily due to which pharmacokinetic process?
A. Enterohepatic recycling prevents oral nitroglycerin from reaching therapeutic levels.
B. The first-pass effect extensively metabolizes nitroglycerin in the liver before it
reaches systemic circulation. [CORRECT]
C. Zero-order kinetics causes unpredictable plasma concentrations of oral nitroglycerin.
D. Redistribution of nitroglycerin into adipose tissue limits its cardiac effects.
Correct Answer: B
Rationale: Nitroglycerin undergoes extensive first-pass hepatic metabolism, rendering
oral administration ineffective; sublingual administration bypasses this effect by
entering systemic circulation directly. Enterohepatic recycling involves biliary excretion
and intestinal reabsorption, not first-pass metabolism.
,Q3: A 70-year-old patient with decreased serum albumin is prescribed a highly
protein-bound drug. The nurse anticipates which clinical effect?
A. Decreased drug effect due to reduced protein binding in plasma.
B. Increased free drug concentration and potential for toxicity. [CORRECT]
C. No change in drug distribution because albumin does not affect pharmacokinetics.
D. Increased drug metabolism due to enhanced hepatic blood flow.
Correct Answer: B
Rationale: Decreased albumin reduces protein binding, increasing the free (unbound,
pharmacologically active) fraction of highly protein-bound drugs, which can lead to
enhanced effects and toxicity. Free drug is the active form available to exert
pharmacologic effects and be metabolized.
Q4: A drug has a half-life of 6 hours. Approximately how long will it take to reach
steady-state concentration with continuous administration?
A. 6 hours, which represents one half-life.
B. 12 hours, which represents two half-lives.
C. 24 hours, which represents four half-lives.
D. 30 hours, which represents five half-lives. [CORRECT]
Correct Answer: D
Rationale: Steady-state concentration is typically reached after 4-5 half-lives; with a
6-hour half-life, this equals 24-30 hours. At steady state, the rate of drug administration
equals the rate of elimination, resulting in stable plasma concentrations.
Q5: A patient is prescribed a loading dose of 500 mg followed by a maintenance dose of
100 mg every 6 hours. The drug has a volume of distribution of 50 L. What is the
expected plasma concentration immediately after the loading dose?
A. 5 mcg/mL
B. 10 mcg/mL [CORRECT]
C. 15 mcg/mL
D. 20 mcg/mL
Correct Answer: B
Rationale: Concentration = Dose / Vd = 500 mg / 50 L = 10 mg/L = 10 mcg/mL. Loading
doses rapidly achieve therapeutic concentrations by filling the volume of distribution,
allowing immediate therapeutic effect before steady state is reached.
,Q6: A nurse is teaching a patient about pharmacodynamics. Which statement best
describes the mechanism of action of a drug agonist?
A. An agonist blocks receptor activation without producing a response.
B. An agonist binds to a receptor and produces a physiologic response. [CORRECT]
C. An agonist increases the metabolism of other drugs at hepatic enzyme sites.
D. An agonist prevents drug absorption in the gastrointestinal tract.
Correct Answer: B
Rationale: An agonist binds to receptors and activates them to produce a physiologic
response, whereas antagonists block receptor activation without producing a response.
Partial agonists produce submaximal responses even at full receptor occupancy.
Q7: A patient taking warfarin is started on a new medication that induces cytochrome
P450 enzymes. The nurse anticipates which clinical change?
A. Increased warfarin effect and elevated bleeding risk.
B. Decreased warfarin effect and potential for thromboembolic events. [CORRECT]
C. No change in warfarin plasma concentration or anticoagulant effect.
D. Increased warfarin absorption from the gastrointestinal tract.
Correct Answer: B
Rationale: CYP450 enzyme induction increases warfarin metabolism, decreasing its
plasma concentration and anticoagulant effect, potentially leading to thromboembolic
events. Enzyme inducers such as rifampin and carbamazepine accelerate drug
clearance and may necessitate warfarin dose increases.
Q8: A patient on warfarin with a therapeutic INR of 2.5 is prescribed
trimethoprim-sulfamethoxazole for a urinary tract infection. The nurse should monitor
closely for which potential interaction?
A. Decreased INR and risk of clot formation.
B. Increased INR and elevated bleeding risk. [CORRECT]
C. No clinically significant interaction exists between these medications.
D. Decreased effectiveness of the antibiotic due to warfarin binding.
Correct Answer: B
Rationale: TMP-SMX inhibits CYP2C9 metabolism of warfarin and displaces it from
protein binding sites, increasing INR and bleeding risk. Antibiotics also alter gut flora
that produce vitamin K, further potentiating warfarin's anticoagulant effect.
, Q9: A nurse is reviewing a drug's therapeutic index with a student nurse. Which
statement about therapeutic index is correct?
A. A narrow therapeutic index indicates a wide safety margin between effective and
toxic doses.
B. A drug with a narrow therapeutic index requires frequent therapeutic drug monitoring
to prevent toxicity. [CORRECT]
C. The therapeutic index is calculated as the ratio of ED50 to LD50.
D. Drugs with wide therapeutic indices never cause adverse effects or toxicity.
Correct Answer: B
Rationale: A narrow therapeutic index (small ratio of toxic to therapeutic dose) requires
frequent drug level monitoring to prevent toxicity, as seen with digoxin, lithium,
phenytoin, and warfarin. The therapeutic index is actually the ratio of TD50 to ED50 (or
LD50 to ED50 in animals).
Q10: A patient has been taking maximum daily doses of acetaminophen for 3 weeks for
chronic osteoarthritis pain. The nurse should monitor for which adverse effect?
A. Gastrointestinal bleeding and peptic ulcer disease.
B. Hepatotoxicity from accumulation of the toxic metabolite NAPQI. [CORRECT]
C. Nephrotoxicity manifesting as acute tubular necrosis.
D. Ototoxicity with tinnitus and hearing loss.
Correct Answer: B
Rationale: Chronic high-dose acetaminophen exhausts hepatic glutathione stores,
leading to hepatic necrosis via toxic NAPQI metabolite accumulation. Unlike NSAIDs,
acetaminophen does not typically cause GI bleeding, and it is not associated with
nephrotoxicity or ototoxicity at therapeutic doses.
Q11: Which phase of pharmacokinetics is primarily affected by hepatic blood flow,
protein binding, and enzyme activity?
A. Absorption is primarily affected by hepatic blood flow and protein binding.
B. Distribution depends mainly on hepatic blood flow and enzyme activity.
C. Metabolism is significantly influenced by hepatic blood flow and protein binding.
[CORRECT]
D. Excretion is primarily determined by hepatic blood flow and enzyme activity.
Correct Answer: C
Rationale: Hepatic metabolism depends on hepatic blood flow (delivering drug to the
liver), protein binding (only free drug is available for metabolism), and enzymatic
