Page 1 of 170
Pharmacokinetic, Pharmacodynamic,
and Ethical/Legal Aspects of Prescribing
| 2026 Update with complete solutions
Question 1
The term “bioavailability” (F) refers to:
A) The speed at which a drug reaches the bloodstream
B) The fraction of an administered dose that reaches systemic
circulation unchanged
C) The volume of distribution of a drug
D) The time to peak concentration
✅ Answer: B
Rationale: Bioavailability is the fraction (0 to 1) of the
administered drug that enters the systemic circulation in its active,
unchanged form. It is influenced by first-pass metabolism,
,Page 2 of 170
solubility, and formulation. Intravenous drugs have 100%
bioavailability.
Question 2
A drug undergoes extensive first-pass metabolism in the liver.
Which route of administration would most significantly increase
its bioavailability?
A) Oral
B) Sublingual
C) Intravenous
D) Both B and C
✅ Answer: D
Rationale: Sublingual (and buccal) routes bypass portal
circulation and thus avoid first-pass metabolism. Intravenous (IV)
also bypasses first-pass because the drug enters systemic
,Page 3 of 170
circulation directly. Oral route (A) would have the lowest
bioavailability for such a drug.
Question 3
Which of the following factors increases gastrointestinal
absorption of oral medications?
A) Presence of food that binds the drug (e.g., tetracycline with
dairy)
B) Increased gastric motility (diarrhea)
C) Increased splanchnic blood flow (e.g., exercise)
D) High gastric pH (e.g., antacids) for weak bases
✅ Answer: C
Rationale: Increased blood flow to the GI tract enhances
absorption by maintaining a concentration gradient. Food
binding (A) decreases absorption. Rapid motility (B) reduces
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contact time, decreasing absorption. High gastric pH (D) reduces
absorption of weak bases (they become more ionized).
Question 4
A patient takes a proton pump inhibitor (PPI) daily. This will most
likely affect absorption of which drug?
A) Ketoconazole (requires acidic pH for solubility)
B) Metformin (absorbed in small intestine, pH-independent)
C) Digoxin (affected by motility, not pH)
D) Lisinopril (pH-independent)
✅ Answer: A
Rationale: PPIs raise gastric pH. Ketoconazole (and
itraconazole) require low pH for dissolution and absorption.
Reduced absorption may lead to therapeutic failure. Other drugs
Pharmacokinetic, Pharmacodynamic,
and Ethical/Legal Aspects of Prescribing
| 2026 Update with complete solutions
Question 1
The term “bioavailability” (F) refers to:
A) The speed at which a drug reaches the bloodstream
B) The fraction of an administered dose that reaches systemic
circulation unchanged
C) The volume of distribution of a drug
D) The time to peak concentration
✅ Answer: B
Rationale: Bioavailability is the fraction (0 to 1) of the
administered drug that enters the systemic circulation in its active,
unchanged form. It is influenced by first-pass metabolism,
,Page 2 of 170
solubility, and formulation. Intravenous drugs have 100%
bioavailability.
Question 2
A drug undergoes extensive first-pass metabolism in the liver.
Which route of administration would most significantly increase
its bioavailability?
A) Oral
B) Sublingual
C) Intravenous
D) Both B and C
✅ Answer: D
Rationale: Sublingual (and buccal) routes bypass portal
circulation and thus avoid first-pass metabolism. Intravenous (IV)
also bypasses first-pass because the drug enters systemic
,Page 3 of 170
circulation directly. Oral route (A) would have the lowest
bioavailability for such a drug.
Question 3
Which of the following factors increases gastrointestinal
absorption of oral medications?
A) Presence of food that binds the drug (e.g., tetracycline with
dairy)
B) Increased gastric motility (diarrhea)
C) Increased splanchnic blood flow (e.g., exercise)
D) High gastric pH (e.g., antacids) for weak bases
✅ Answer: C
Rationale: Increased blood flow to the GI tract enhances
absorption by maintaining a concentration gradient. Food
binding (A) decreases absorption. Rapid motility (B) reduces
, Page 4 of 170
contact time, decreasing absorption. High gastric pH (D) reduces
absorption of weak bases (they become more ionized).
Question 4
A patient takes a proton pump inhibitor (PPI) daily. This will most
likely affect absorption of which drug?
A) Ketoconazole (requires acidic pH for solubility)
B) Metformin (absorbed in small intestine, pH-independent)
C) Digoxin (affected by motility, not pH)
D) Lisinopril (pH-independent)
✅ Answer: A
Rationale: PPIs raise gastric pH. Ketoconazole (and
itraconazole) require low pH for dissolution and absorption.
Reduced absorption may lead to therapeutic failure. Other drugs
