D441 Pharmacology Exam 1 Study Guide 2026 |WGU
1. Which phase of pharmacokinetics involves the movement of a drug from its
site of administration into the bloodstream?
A. Metabolism
B. Excretion
C. Distribution
D. Absorption
Answer: D
Rationale: Absorption is the process by which a drug moves from the site of
administration into the blood. Metabolism refers to chemical changes, distribution to
movement within the body, and excretion to removal.
2. A drug’s half-life is defined as the time required for the amount of drug in the
body to decrease by:
A. 25%
B. 50%
C. 75%
D. 100%
Answer: B
Rationale: The half-life of a drug is the time required for the concentration or amount of
drug in the body to be reduced by exactly one-half (50%).
,3. Which organ is primarily responsible for the metabolism of most drugs?
A. Kidneys
B. Lungs
C. Liver
D. Small Intestine
Answer: C
Rationale: The liver is the primary site of drug metabolism, utilizing enzymes like the
cytochrome P450 system to transform drugs into metabolites.
4. What occurs during the ‘first-pass effect’?
A. The drug is excreted by the kidneys before reaching the heart.
B. The drug is metabolized by the liver before reaching systemic circulation.
C. The drug is absorbed through the skin into the lymph nodes.
D. The drug binds to plasma proteins in the blood immediately.
Answer: B
Rationale: The first-pass effect occurs when an oral drug is absorbed from the GI tract and
carried to the liver via the portal vein, where it is extensively metabolized before reaching
the rest of the body.
5. Which route of administration provides 100% bioavailability?
A. Oral (PO)
B. Subcutaneous (SQ)
C. Intravenous (IV)
D. Intramuscular (IM)
Answer: C
Rationale: Bioavailability is the fraction of an administered dose that reaches the systemic
circulation. IV administration enters the blood directly, resulting in 100% bioavailability.
, 6. A drug that binds to a receptor and produces a biological response is known
as:
A. An antagonist
B. A blocker
C. An agonist
D. An inhibitor
Answer: C
Rationale: An agonist is a molecule that activates a receptor to produce a biological
response. An antagonist blocks the receptor to prevent a response.
7. What is the primary factor that determines the frequency of drug dosing?
A. Drug half-life
B. Drug bioavailability
C. Drug cost
D. Route of administration
Answer: A
Rationale: The half-life determines how long a drug remains in the body and is used to
establish the dosing interval to maintain therapeutic levels.
8. The therapeutic index (TI) of a drug is a ratio that compares:
A. Generic name to brand name cost
B. The blood concentration to the dose given
C. Absorption rate to excretion rate
D. The toxic dose to the effective dose
Answer: D
Rationale: The therapeutic index is the ratio of the dose that causes toxicity to the dose
that produces a therapeutic effect. A low TI indicates a narrow safety margin.
1. Which phase of pharmacokinetics involves the movement of a drug from its
site of administration into the bloodstream?
A. Metabolism
B. Excretion
C. Distribution
D. Absorption
Answer: D
Rationale: Absorption is the process by which a drug moves from the site of
administration into the blood. Metabolism refers to chemical changes, distribution to
movement within the body, and excretion to removal.
2. A drug’s half-life is defined as the time required for the amount of drug in the
body to decrease by:
A. 25%
B. 50%
C. 75%
D. 100%
Answer: B
Rationale: The half-life of a drug is the time required for the concentration or amount of
drug in the body to be reduced by exactly one-half (50%).
,3. Which organ is primarily responsible for the metabolism of most drugs?
A. Kidneys
B. Lungs
C. Liver
D. Small Intestine
Answer: C
Rationale: The liver is the primary site of drug metabolism, utilizing enzymes like the
cytochrome P450 system to transform drugs into metabolites.
4. What occurs during the ‘first-pass effect’?
A. The drug is excreted by the kidneys before reaching the heart.
B. The drug is metabolized by the liver before reaching systemic circulation.
C. The drug is absorbed through the skin into the lymph nodes.
D. The drug binds to plasma proteins in the blood immediately.
Answer: B
Rationale: The first-pass effect occurs when an oral drug is absorbed from the GI tract and
carried to the liver via the portal vein, where it is extensively metabolized before reaching
the rest of the body.
5. Which route of administration provides 100% bioavailability?
A. Oral (PO)
B. Subcutaneous (SQ)
C. Intravenous (IV)
D. Intramuscular (IM)
Answer: C
Rationale: Bioavailability is the fraction of an administered dose that reaches the systemic
circulation. IV administration enters the blood directly, resulting in 100% bioavailability.
, 6. A drug that binds to a receptor and produces a biological response is known
as:
A. An antagonist
B. A blocker
C. An agonist
D. An inhibitor
Answer: C
Rationale: An agonist is a molecule that activates a receptor to produce a biological
response. An antagonist blocks the receptor to prevent a response.
7. What is the primary factor that determines the frequency of drug dosing?
A. Drug half-life
B. Drug bioavailability
C. Drug cost
D. Route of administration
Answer: A
Rationale: The half-life determines how long a drug remains in the body and is used to
establish the dosing interval to maintain therapeutic levels.
8. The therapeutic index (TI) of a drug is a ratio that compares:
A. Generic name to brand name cost
B. The blood concentration to the dose given
C. Absorption rate to excretion rate
D. The toxic dose to the effective dose
Answer: D
Rationale: The therapeutic index is the ratio of the dose that causes toxicity to the dose
that produces a therapeutic effect. A low TI indicates a narrow safety margin.
