BSN 315 PHARMACOLOGY II NIGHTINGALE
COLLEGE 2025/2026 EXAM 300 ACTUAL
QUESTIONS AND CORRECT ANSWERS WITH
RATIONALE LATEST UPDATE ALREADY
GRADED A+ ASSURED PASS
SECTION 1: ADVANCED PHARMACOKINETICS &
PHARMACODYNAMICS (Questions 1–30)
1. A client is prescribed digoxin for heart failure. What is the primary mechanism
of action of digoxin?
A) Increases heart rate
B) Inhibits the sodium-potassium ATPase pump
C) Promotes vasodilation
D) Decreases contractility
Answer: B) Inhibits the sodium-potassium ATPase pump
Rationale: Digoxin inhibits the Na+/K+ ATPase pump, increasing intracellular
calcium and enhancing myocardial contractility (positive inotropic effect). This
improves cardiac output in heart failure.
2. A nurse is administering a medication with a half-life of 4 hours. If the initial
dose is 400 mg, what is the approximate amount remaining after 8 hours?
A) 100 mg
B) 200 mg
C) 300 mg
D) 400 mg
Answer: A) 100 mg
Rationale: After 8 hours (2 half-lives): 400 mg → 200 mg (4 hrs) → 100 mg (8
hrs). The half-life is the time required for the body to eliminate 50% of the drug.
3. A client taking warfarin tells the nurse, "I started drinking grapefruit juice every
morning." Which statement by the nurse is most appropriate?
A) Grapefruit juice will increase the INR; reduce your warfarin dose by half.
,B) Grapefruit juice can interact with warfarin and increase bleeding risk; notify
your provider.
C) Grapefruit juice has no effect on warfarin; continue as usual.
D) Grapefruit juice will decrease the effectiveness of warfarin.
Answer: B) Grapefruit juice can interact with warfarin and increase bleeding risk;
notify your provider.
Rationale: Grapefruit inhibits CYP3A4, which can increase warfarin levels and
bleeding risk. The nurse should advise the client to notify the provider and monitor
INR closely.
4. What is the primary route of elimination for most water-soluble drugs?
A) Lungs
B) Kidneys
C) Liver
D) Skin
Answer: B) Kidneys
Rationale: Water-soluble drugs are primarily excreted unchanged via renal
filtration. Renal impairment requires dose adjustments for many water-soluble
medications.
5. A patient starts grapefruit juice while on a CYP3A4 substrate. What is the
expected effect?
A) Decreased drug efficacy
B) Increased drug toxicity
C) No interaction
D) Reduced absorption
Answer: B) Increased drug toxicity
Rationale: Grapefruit inhibits CYP3A4, reducing metabolism of substrate drugs
and increasing drug levels, which can lead to toxicity.
6. What is the therapeutic serum range for lithium?
A) 0.2–0.4 mEq/L
B) 0.6–1.2 mEq/L
C) 1.5–2.0 mEq/L
D) 2.5–3.0 mEq/L
Answer: B) 0.6–1.2 mEq/L
,Rationale: The therapeutic range for lithium in bipolar disorder management is
0.6–1.2 mEq/L. Levels above 1.5 mEq/L are toxic.
7. Vancomycin is administered for MRSA. What is the preferred route for systemic
infection?
A) Oral
B) Intramuscular
C) Intravenous
D) Topical
Answer: C) Intravenous
Rationale: IV vancomycin is preferred for systemic MRSA infections. Oral
vancomycin is used only for C. difficile colitis because it is not absorbed
systemically.
8. A nurse is reviewing the medication profile of an 82-year-old client with chronic
renal impairment (eGFR 25 mL/min) who is prescribed gabapentin 300 mg PO
TID. Which of the following is the priority nursing action?
A) Administer the medication as prescribed because the dose is within the standard
range.
B) Contact the provider to request a dose reduction due to renal impairment.
C) Hold the dose and monitor the client's serum creatinine for 24 hours.
D) Administer the medication with a full glass of orange juice to enhance
absorption.
Answer: B) Contact the provider to request a dose reduction due to renal
impairment.
Rationale: Gabapentin is primarily renally excreted unchanged, and the dose must
be reduced in renal impairment to avoid neurotoxicity. For an eGFR of 25 mL/min,
the recommended maintenance dose is 100–300 mg once daily, not TID.
9. A client is prescribed a medication with a half-life of 4 days. Approximately
how long will it take to reach steady state?
A) 4 days
B) 8 days
C) 16–20 days
D) 30 days
Answer: C) 16–20 days
, Rationale: Steady state is typically reached after 4–5 half-lives. For a drug with a
4-day half-life, steady state occurs in approximately 16–20 days.
10. Which factor most significantly affects the bioavailability of an orally
administered drug?
A) First-pass hepatic metabolism
B) Renal function
C) Protein binding
D) Volume of distribution
Answer: A) First-pass hepatic metabolism
Rationale: First-pass metabolism reduces the amount of drug reaching systemic
circulation after oral administration. Drugs with high first-pass effects have low
oral bioavailability.
11. A client is taking phenytoin and reports increased seizure activity. The nurse
notes the client recently started taking omeprazole. What is the most likely
explanation?
A) Omeprazole increases phenytoin absorption
B) Omeprazole induces CYP enzymes, decreasing phenytoin levels
C) Omeprazole inhibits CYP enzymes, increasing phenytoin levels
D) Omeprazole has no interaction with phenytoin
Answer: B) Omeprazole induces CYP enzymes, decreasing phenytoin levels
Rationale: Omeprazole is a CYP2C19 inhibitor and can increase phenytoin levels,
but it may also induce other enzymes. The decreased seizure control suggests
reduced phenytoin levels. Close monitoring is required.
12. What is the definition of "therapeutic index"?
A) The ratio of the toxic dose to the therapeutic dose
B) The ratio of the lethal dose to the effective dose
C) The ratio of the minimum effective concentration to the maximum safe
concentration
D) The ratio of the drug's half-life to its clearance
Answer: A) The ratio of the toxic dose to the therapeutic dose
Rationale: The therapeutic index is the ratio of the toxic dose (TD50) to the
therapeutic dose (ED50). A narrow therapeutic index means small differences
between therapeutic and toxic doses.
COLLEGE 2025/2026 EXAM 300 ACTUAL
QUESTIONS AND CORRECT ANSWERS WITH
RATIONALE LATEST UPDATE ALREADY
GRADED A+ ASSURED PASS
SECTION 1: ADVANCED PHARMACOKINETICS &
PHARMACODYNAMICS (Questions 1–30)
1. A client is prescribed digoxin for heart failure. What is the primary mechanism
of action of digoxin?
A) Increases heart rate
B) Inhibits the sodium-potassium ATPase pump
C) Promotes vasodilation
D) Decreases contractility
Answer: B) Inhibits the sodium-potassium ATPase pump
Rationale: Digoxin inhibits the Na+/K+ ATPase pump, increasing intracellular
calcium and enhancing myocardial contractility (positive inotropic effect). This
improves cardiac output in heart failure.
2. A nurse is administering a medication with a half-life of 4 hours. If the initial
dose is 400 mg, what is the approximate amount remaining after 8 hours?
A) 100 mg
B) 200 mg
C) 300 mg
D) 400 mg
Answer: A) 100 mg
Rationale: After 8 hours (2 half-lives): 400 mg → 200 mg (4 hrs) → 100 mg (8
hrs). The half-life is the time required for the body to eliminate 50% of the drug.
3. A client taking warfarin tells the nurse, "I started drinking grapefruit juice every
morning." Which statement by the nurse is most appropriate?
A) Grapefruit juice will increase the INR; reduce your warfarin dose by half.
,B) Grapefruit juice can interact with warfarin and increase bleeding risk; notify
your provider.
C) Grapefruit juice has no effect on warfarin; continue as usual.
D) Grapefruit juice will decrease the effectiveness of warfarin.
Answer: B) Grapefruit juice can interact with warfarin and increase bleeding risk;
notify your provider.
Rationale: Grapefruit inhibits CYP3A4, which can increase warfarin levels and
bleeding risk. The nurse should advise the client to notify the provider and monitor
INR closely.
4. What is the primary route of elimination for most water-soluble drugs?
A) Lungs
B) Kidneys
C) Liver
D) Skin
Answer: B) Kidneys
Rationale: Water-soluble drugs are primarily excreted unchanged via renal
filtration. Renal impairment requires dose adjustments for many water-soluble
medications.
5. A patient starts grapefruit juice while on a CYP3A4 substrate. What is the
expected effect?
A) Decreased drug efficacy
B) Increased drug toxicity
C) No interaction
D) Reduced absorption
Answer: B) Increased drug toxicity
Rationale: Grapefruit inhibits CYP3A4, reducing metabolism of substrate drugs
and increasing drug levels, which can lead to toxicity.
6. What is the therapeutic serum range for lithium?
A) 0.2–0.4 mEq/L
B) 0.6–1.2 mEq/L
C) 1.5–2.0 mEq/L
D) 2.5–3.0 mEq/L
Answer: B) 0.6–1.2 mEq/L
,Rationale: The therapeutic range for lithium in bipolar disorder management is
0.6–1.2 mEq/L. Levels above 1.5 mEq/L are toxic.
7. Vancomycin is administered for MRSA. What is the preferred route for systemic
infection?
A) Oral
B) Intramuscular
C) Intravenous
D) Topical
Answer: C) Intravenous
Rationale: IV vancomycin is preferred for systemic MRSA infections. Oral
vancomycin is used only for C. difficile colitis because it is not absorbed
systemically.
8. A nurse is reviewing the medication profile of an 82-year-old client with chronic
renal impairment (eGFR 25 mL/min) who is prescribed gabapentin 300 mg PO
TID. Which of the following is the priority nursing action?
A) Administer the medication as prescribed because the dose is within the standard
range.
B) Contact the provider to request a dose reduction due to renal impairment.
C) Hold the dose and monitor the client's serum creatinine for 24 hours.
D) Administer the medication with a full glass of orange juice to enhance
absorption.
Answer: B) Contact the provider to request a dose reduction due to renal
impairment.
Rationale: Gabapentin is primarily renally excreted unchanged, and the dose must
be reduced in renal impairment to avoid neurotoxicity. For an eGFR of 25 mL/min,
the recommended maintenance dose is 100–300 mg once daily, not TID.
9. A client is prescribed a medication with a half-life of 4 days. Approximately
how long will it take to reach steady state?
A) 4 days
B) 8 days
C) 16–20 days
D) 30 days
Answer: C) 16–20 days
, Rationale: Steady state is typically reached after 4–5 half-lives. For a drug with a
4-day half-life, steady state occurs in approximately 16–20 days.
10. Which factor most significantly affects the bioavailability of an orally
administered drug?
A) First-pass hepatic metabolism
B) Renal function
C) Protein binding
D) Volume of distribution
Answer: A) First-pass hepatic metabolism
Rationale: First-pass metabolism reduces the amount of drug reaching systemic
circulation after oral administration. Drugs with high first-pass effects have low
oral bioavailability.
11. A client is taking phenytoin and reports increased seizure activity. The nurse
notes the client recently started taking omeprazole. What is the most likely
explanation?
A) Omeprazole increases phenytoin absorption
B) Omeprazole induces CYP enzymes, decreasing phenytoin levels
C) Omeprazole inhibits CYP enzymes, increasing phenytoin levels
D) Omeprazole has no interaction with phenytoin
Answer: B) Omeprazole induces CYP enzymes, decreasing phenytoin levels
Rationale: Omeprazole is a CYP2C19 inhibitor and can increase phenytoin levels,
but it may also induce other enzymes. The decreased seizure control suggests
reduced phenytoin levels. Close monitoring is required.
12. What is the definition of "therapeutic index"?
A) The ratio of the toxic dose to the therapeutic dose
B) The ratio of the lethal dose to the effective dose
C) The ratio of the minimum effective concentration to the maximum safe
concentration
D) The ratio of the drug's half-life to its clearance
Answer: A) The ratio of the toxic dose to the therapeutic dose
Rationale: The therapeutic index is the ratio of the toxic dose (TD50) to the
therapeutic dose (ED50). A narrow therapeutic index means small differences
between therapeutic and toxic doses.
