WGU D398 Introduction to
Pharmacology | Objective
Assessments | OA V1, V2 and V3
| All OA Versions | 234 Questions
and Answers | Update | 100%
Correct.
Q1. A drug with high first-pass effect is administered orally. What
adjustment is most likely needed?
A) Lower oral dose
B) Higher oral dose
C) Change to intravenous bolus without dose change
D) Administer with a CYP450 inhibitor
✅ Correct Answer: B
Rationale: High first-pass metabolism means the liver metabolizes a large
portion of the drug before it reaches systemic circulation, reducing
bioavailability. A higher oral dose compensates for this loss. (A) Lower dose
would worsen subtherapeutic levels. (C) IV bypasses first-pass but requires a
lower dose, not the same dose. (D) CYP450 inhibitor increases toxicity risk and
is not standard for first-pass compensation.
Q2. A patient takes a drug that is a weak acid (aspirin) and
simultaneously ingests a drug that raises gastric pH. What effect on
aspirin absorption is expected?
A) Increased absorption
B) Decreased absorption
C) No change in absorption
D) Complete prevention of absorption
,✅ Correct Answer: B
Rationale: Weak acids are better absorbed in acidic environments (non-
ionized form). Raising gastric pH makes the environment more alkaline,
causing aspirin to become ionized, which reduces its absorption. (A) would
occur if pH were lowered. (C) is incorrect because pH change directly affects
ionization. (D) is too absolute.
Q3. Which pharmacokinetic process is defined as the movement of a
drug from the bloodstream into the tissues?
A) Absorption
B) Distribution
C) Metabolism
D) Excretion
✅ Correct Answer: B
Rationale: Distribution is the process by which a drug reversibly leaves the
bloodstream and enters interstitial fluid and tissues. (A) Absorption is
movement from administration site into blood. (C) Metabolism is
biotransformation. (D) Excretion is elimination from the body.
Q4. A patient with severe liver failure receives a drug that is highly
metabolized by the liver. What change in half-life is expected?
A) Decreased half-life
B) Increased half-life
C) No change in half-life
D) Half-life becomes unpredictable but usually shorter
✅ Correct Answer: B
Rationale: Reduced liver function slows drug metabolism, prolonging half-life
and increasing risk of toxicity. (A) would occur with increased metabolism. (C)
is incorrect because liver failure directly alters metabolism. (D) is incorrect;
half-life predictably increases.
,Q5. Which route of administration completely bypasses the first-pass
effect?
A) Oral
B) Sublingual
C) Rectal
D) Intramuscular
✅ Correct Answer: B
Rationale: Sublingual administration allows drug to absorb directly into
systemic circulation via the sublingual vein, bypassing the portal system and
liver. (A) Oral undergoes first-pass. (C) Rectal partially bypasses but not
completely. (D) Intramuscular bypasses first-pass but is not the classic
"complete bypass" example; sublingual is the best answer.
Q6. A drug has a volume of distribution (Vd) of 500 L in a 70 kg adult.
This suggests the drug:
A) Is confined to the plasma
B) Is highly bound to plasma proteins
C) Is extensively distributed into tissues
D) Cannot cross the blood-brain barrier
✅ Correct Answer: C
Rationale: Normal plasma volume is ~3 L; total body water is ~42 L. A Vd of
500 L greatly exceeds total body water, indicating extensive tissue
binding/sequestration. (A) and (B) would produce low Vd (~3-5 L). (D) is
unrelated to high Vd.
Q7. Which statement best describes the blood-brain barrier (BBB)?
A) It allows all lipid-soluble drugs to freely enter
B) It consists of tight junctions that restrict passage of water-soluble drugs
, C) It is absent in neonates
D) It actively pumps all drugs out of the brain
✅ Correct Answer: B
Rationale: The BBB is formed by endothelial tight junctions that restrict
paracellular diffusion, especially for water-soluble drugs. (A) is false; lipid-
soluble drugs do cross but not all "freely" without transporters. (C) is false;
BBB is present but immature. (D) is false; only some drugs are actively effluxed.
Q8. A medication follows zero-order kinetics. What does this mean for
drug elimination?
A) A constant fraction of the drug is eliminated per unit time
B) A constant amount of the drug is eliminated per unit time
C) Elimination rate increases proportionally with concentration
D) Elimination is fastest at low concentrations
✅ Correct Answer: B
Rationale: Zero-order kinetics = constant amount per time (e.g., 10 mg/hour
regardless of concentration). (A) describes first-order kinetics. (C) describes
first-order. (D) is opposite of zero-order behavior.
Q9. Phenytoin follows zero-order kinetics at therapeutic doses. If a
patient's dose is increased slightly, what will happen?
A) Proportionally small increase in drug levels
B) Disproportionately large increase in drug levels
C) No change in drug levels
D) Decrease in drug levels due to auto-induction
✅ Correct Answer: B
Rationale: With zero-order kinetics, metabolic enzymes are saturated. A small
dose increase causes a large, unpredictable rise in serum levels, risking toxicity.
(A) describes first-order kinetics. (C) is false. (D) is false; auto-induction is not
relevant here.
Pharmacology | Objective
Assessments | OA V1, V2 and V3
| All OA Versions | 234 Questions
and Answers | Update | 100%
Correct.
Q1. A drug with high first-pass effect is administered orally. What
adjustment is most likely needed?
A) Lower oral dose
B) Higher oral dose
C) Change to intravenous bolus without dose change
D) Administer with a CYP450 inhibitor
✅ Correct Answer: B
Rationale: High first-pass metabolism means the liver metabolizes a large
portion of the drug before it reaches systemic circulation, reducing
bioavailability. A higher oral dose compensates for this loss. (A) Lower dose
would worsen subtherapeutic levels. (C) IV bypasses first-pass but requires a
lower dose, not the same dose. (D) CYP450 inhibitor increases toxicity risk and
is not standard for first-pass compensation.
Q2. A patient takes a drug that is a weak acid (aspirin) and
simultaneously ingests a drug that raises gastric pH. What effect on
aspirin absorption is expected?
A) Increased absorption
B) Decreased absorption
C) No change in absorption
D) Complete prevention of absorption
,✅ Correct Answer: B
Rationale: Weak acids are better absorbed in acidic environments (non-
ionized form). Raising gastric pH makes the environment more alkaline,
causing aspirin to become ionized, which reduces its absorption. (A) would
occur if pH were lowered. (C) is incorrect because pH change directly affects
ionization. (D) is too absolute.
Q3. Which pharmacokinetic process is defined as the movement of a
drug from the bloodstream into the tissues?
A) Absorption
B) Distribution
C) Metabolism
D) Excretion
✅ Correct Answer: B
Rationale: Distribution is the process by which a drug reversibly leaves the
bloodstream and enters interstitial fluid and tissues. (A) Absorption is
movement from administration site into blood. (C) Metabolism is
biotransformation. (D) Excretion is elimination from the body.
Q4. A patient with severe liver failure receives a drug that is highly
metabolized by the liver. What change in half-life is expected?
A) Decreased half-life
B) Increased half-life
C) No change in half-life
D) Half-life becomes unpredictable but usually shorter
✅ Correct Answer: B
Rationale: Reduced liver function slows drug metabolism, prolonging half-life
and increasing risk of toxicity. (A) would occur with increased metabolism. (C)
is incorrect because liver failure directly alters metabolism. (D) is incorrect;
half-life predictably increases.
,Q5. Which route of administration completely bypasses the first-pass
effect?
A) Oral
B) Sublingual
C) Rectal
D) Intramuscular
✅ Correct Answer: B
Rationale: Sublingual administration allows drug to absorb directly into
systemic circulation via the sublingual vein, bypassing the portal system and
liver. (A) Oral undergoes first-pass. (C) Rectal partially bypasses but not
completely. (D) Intramuscular bypasses first-pass but is not the classic
"complete bypass" example; sublingual is the best answer.
Q6. A drug has a volume of distribution (Vd) of 500 L in a 70 kg adult.
This suggests the drug:
A) Is confined to the plasma
B) Is highly bound to plasma proteins
C) Is extensively distributed into tissues
D) Cannot cross the blood-brain barrier
✅ Correct Answer: C
Rationale: Normal plasma volume is ~3 L; total body water is ~42 L. A Vd of
500 L greatly exceeds total body water, indicating extensive tissue
binding/sequestration. (A) and (B) would produce low Vd (~3-5 L). (D) is
unrelated to high Vd.
Q7. Which statement best describes the blood-brain barrier (BBB)?
A) It allows all lipid-soluble drugs to freely enter
B) It consists of tight junctions that restrict passage of water-soluble drugs
, C) It is absent in neonates
D) It actively pumps all drugs out of the brain
✅ Correct Answer: B
Rationale: The BBB is formed by endothelial tight junctions that restrict
paracellular diffusion, especially for water-soluble drugs. (A) is false; lipid-
soluble drugs do cross but not all "freely" without transporters. (C) is false;
BBB is present but immature. (D) is false; only some drugs are actively effluxed.
Q8. A medication follows zero-order kinetics. What does this mean for
drug elimination?
A) A constant fraction of the drug is eliminated per unit time
B) A constant amount of the drug is eliminated per unit time
C) Elimination rate increases proportionally with concentration
D) Elimination is fastest at low concentrations
✅ Correct Answer: B
Rationale: Zero-order kinetics = constant amount per time (e.g., 10 mg/hour
regardless of concentration). (A) describes first-order kinetics. (C) describes
first-order. (D) is opposite of zero-order behavior.
Q9. Phenytoin follows zero-order kinetics at therapeutic doses. If a
patient's dose is increased slightly, what will happen?
A) Proportionally small increase in drug levels
B) Disproportionately large increase in drug levels
C) No change in drug levels
D) Decrease in drug levels due to auto-induction
✅ Correct Answer: B
Rationale: With zero-order kinetics, metabolic enzymes are saturated. A small
dose increase causes a large, unpredictable rise in serum levels, risking toxicity.
(A) describes first-order kinetics. (C) is false. (D) is false; auto-induction is not
relevant here.
