WGU D398 Introduction to Pharmacology –
Objective Assessments (OA V1, V2 & V3) 150
Multiple Choice Questions with Bold Italic
Answers and Italic Explanations 2026/2027
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PHARMACOKINETICS & PHARMACODYNAMICS
1. A nurse is preparing to administer a medication that requires absorption through the
gastrointestinal tract. Which route of administration would the nurse select?
A) Intravenous
B) Intramuscular
C) Oral
D) Sublingual
Oral administration relies on absorption through the GI tract, making it the correct route for drugs
designed to enter the systemic circulation via the digestive system. Intravenous bypasses absorption
entirely, while intramuscular and sublingual routes also bypass GI absorption .
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2. A patient is prescribed a drug with a high first-pass effect. The nurse anticipates that the medication
will be administered by which route to avoid this effect?
A) Oral
B) Sublingual
C) Rectal
D) Topical
Sublingual administration allows the drug to enter systemic circulation directly via the sublingual
mucosa, avoiding hepatic first-pass metabolism. Oral drugs undergo extensive first-pass effect, while
rectal and topical routes partially avoid but not as completely as sublingual .
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3. Which pharmacokinetic process describes the movement of a drug from the site of administration
into the bloodstream?
A) Distribution
B) Absorption
C) Metabolism
D) Excretion
,Absorption is the process by which a drug moves from its administration site into the bloodstream.
Distribution is transport to tissues, metabolism is biotransformation, and excretion is elimination from
the body .
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4. A medication has a half-life of 4 hours. How much of the original dose will remain in the patient's
system after 12 hours?
A) 50%
B) 25%
C) 12.5%
D) 6.25%
Each half-life reduces the drug concentration by 50%. After 4 hours: 50% remains; after 8 hours: 25%
remains; after 12 hours: 12.5% remains .
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5. A patient with liver cirrhosis is prescribed a drug that is highly metabolized by the liver. The nurse
expects which adjustment to the dosing regimen?
A) Increased dose
B) Decreased dose or extended interval
C) No change needed
D) Increased frequency only
Reduced liver function slows drug metabolism, prolonging half-life and increasing risk of toxicity. A
decreased dose or extended interval prevents accumulation .
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6. 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
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 .
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7. 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
,Distribution is the process by which a drug reversibly leaves the bloodstream and enters interstitial fluid
and tissues .
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8. 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
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 .
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9. 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
Zero-order kinetics means a constant amount per time (e.g., 10 mg/hour regardless of concentration).
First-order kinetics describes elimination of a constant fraction per unit time .
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10. Which organ is primarily responsible for drug metabolism?
A) Kidneys
B) Liver
C) Lungs
D) Heart
The liver is the primary site of drug metabolism through the cytochrome P450 enzyme system. The
kidneys are the primary route of excretion .
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11. Bioavailability refers to:
A) Drug toxicity level
B) Percentage of drug reaching systemic circulation
C) Drug's color and appearance
D) Excretion rate only
Bioavailability is the fraction of an administered dose of drug that reaches the systemic circulation. It is
affected by first-pass metabolism and route of administration .
, \
12. A medication given intravenously has:
A) Delayed onset
B) No absorption phase
C) Low bioavailability
D) Extensive first-pass effect
IV drugs enter the bloodstream directly, bypassing the absorption phase entirely. This results in 100%
bioavailability and immediate onset of action .
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13. Steady state concentration is reached after approximately:
A) 1 half-life
B) 2 half-lives
C) 4-5 half-lives
D) 10 half-lives
Steady state is achieved when drug administration rate equals elimination rate, typically after 4-5 half-
lives of regular dosing .
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14. The therapeutic index of a drug indicates:
A) Drug's cost-effectiveness
B) The margin of safety between effective and toxic doses
C) How often the drug should be taken
D) The drug's half-life
The therapeutic index is the ratio of the toxic dose to the effective dose (TD50/ED50). A narrow TI
indicates a drug with a small margin of safety requiring careful monitoring .
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15. A patient has a therapeutic index (TI) of 2. This indicates the drug is:
A) Extremely safe
B) Moderately safe
C) Narrow therapeutic window, potentially dangerous
D) Safe only in pediatric patients
TI of 2 is narrow (close to 1), meaning the toxic dose is only twice the effective dose, indicating high risk
of toxicity .
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16. Which term describes a drug that activates a receptor to produce a response?
Objective Assessments (OA V1, V2 & V3) 150
Multiple Choice Questions with Bold Italic
Answers and Italic Explanations 2026/2027
\
PHARMACOKINETICS & PHARMACODYNAMICS
1. A nurse is preparing to administer a medication that requires absorption through the
gastrointestinal tract. Which route of administration would the nurse select?
A) Intravenous
B) Intramuscular
C) Oral
D) Sublingual
Oral administration relies on absorption through the GI tract, making it the correct route for drugs
designed to enter the systemic circulation via the digestive system. Intravenous bypasses absorption
entirely, while intramuscular and sublingual routes also bypass GI absorption .
\
2. A patient is prescribed a drug with a high first-pass effect. The nurse anticipates that the medication
will be administered by which route to avoid this effect?
A) Oral
B) Sublingual
C) Rectal
D) Topical
Sublingual administration allows the drug to enter systemic circulation directly via the sublingual
mucosa, avoiding hepatic first-pass metabolism. Oral drugs undergo extensive first-pass effect, while
rectal and topical routes partially avoid but not as completely as sublingual .
\
3. Which pharmacokinetic process describes the movement of a drug from the site of administration
into the bloodstream?
A) Distribution
B) Absorption
C) Metabolism
D) Excretion
,Absorption is the process by which a drug moves from its administration site into the bloodstream.
Distribution is transport to tissues, metabolism is biotransformation, and excretion is elimination from
the body .
\
4. A medication has a half-life of 4 hours. How much of the original dose will remain in the patient's
system after 12 hours?
A) 50%
B) 25%
C) 12.5%
D) 6.25%
Each half-life reduces the drug concentration by 50%. After 4 hours: 50% remains; after 8 hours: 25%
remains; after 12 hours: 12.5% remains .
\
5. A patient with liver cirrhosis is prescribed a drug that is highly metabolized by the liver. The nurse
expects which adjustment to the dosing regimen?
A) Increased dose
B) Decreased dose or extended interval
C) No change needed
D) Increased frequency only
Reduced liver function slows drug metabolism, prolonging half-life and increasing risk of toxicity. A
decreased dose or extended interval prevents accumulation .
\
6. 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
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 .
\
7. 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
,Distribution is the process by which a drug reversibly leaves the bloodstream and enters interstitial fluid
and tissues .
\
8. 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
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 .
\
9. 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
Zero-order kinetics means a constant amount per time (e.g., 10 mg/hour regardless of concentration).
First-order kinetics describes elimination of a constant fraction per unit time .
\
10. Which organ is primarily responsible for drug metabolism?
A) Kidneys
B) Liver
C) Lungs
D) Heart
The liver is the primary site of drug metabolism through the cytochrome P450 enzyme system. The
kidneys are the primary route of excretion .
\
11. Bioavailability refers to:
A) Drug toxicity level
B) Percentage of drug reaching systemic circulation
C) Drug's color and appearance
D) Excretion rate only
Bioavailability is the fraction of an administered dose of drug that reaches the systemic circulation. It is
affected by first-pass metabolism and route of administration .
, \
12. A medication given intravenously has:
A) Delayed onset
B) No absorption phase
C) Low bioavailability
D) Extensive first-pass effect
IV drugs enter the bloodstream directly, bypassing the absorption phase entirely. This results in 100%
bioavailability and immediate onset of action .
\
13. Steady state concentration is reached after approximately:
A) 1 half-life
B) 2 half-lives
C) 4-5 half-lives
D) 10 half-lives
Steady state is achieved when drug administration rate equals elimination rate, typically after 4-5 half-
lives of regular dosing .
\
14. The therapeutic index of a drug indicates:
A) Drug's cost-effectiveness
B) The margin of safety between effective and toxic doses
C) How often the drug should be taken
D) The drug's half-life
The therapeutic index is the ratio of the toxic dose to the effective dose (TD50/ED50). A narrow TI
indicates a drug with a small margin of safety requiring careful monitoring .
\
15. A patient has a therapeutic index (TI) of 2. This indicates the drug is:
A) Extremely safe
B) Moderately safe
C) Narrow therapeutic window, potentially dangerous
D) Safe only in pediatric patients
TI of 2 is narrow (close to 1), meaning the toxic dose is only twice the effective dose, indicating high risk
of toxicity .
\
16. Which term describes a drug that activates a receptor to produce a response?
