,BIOD 351 FINAL EXAM | Pharmacology | Portage
Learning | Questions & Verified Answers | 2026 Edition
1. Which term describes what the body does to a drug, encompassing absorption, distribution,
metabolism, and excretion?
A) Pharmacodynamics
B) Pharmacokinetics
C) Pharmacotherapeutics
D) Toxicology
Correct Answer: Pharmacokinetics
Rationale: Pharmacokinetics is defined as what the body does to the drug and includes the four phases
of ADME: Absorption, Distribution, Metabolism, and Excretion. Pharmacodynamics, in contrast,
describes what the drug does to the body. Pharmacotherapeutics is the use of drugs to treat disease,
and toxicology is the study of harmful effects.
2. A medication that binds to a receptor and triggers a response is best described as a(n):
A) Antagonist
B) Agonist
C) Partial agonist
D) Inverse agonist
Correct Answer: Agonist
Rationale: An agonist binds to a receptor and triggers a response, effectively "turning on" the receptor
by mimicking the action of endogenous ligands. An antagonist binds to a receptor and blocks activation
without producing a response. A partial agonist produces a submaximal response even when all
receptors are occupied.
3. A patient is prescribed a medication that is 90% protein-bound. Which statement about this drug is
TRUE?
,A) The drug is rapidly excreted by the kidneys
B) Only 10% of the drug is pharmacologically active
C) The drug has a large volume of distribution
D) The drug is highly water-soluble
Correct Answer: Only 10% of the drug is pharmacologically active
Rationale: Only the unbound (free) fraction of a drug is pharmacologically active. A drug that is 90%
protein-bound has only 10% free drug available to produce a therapeutic effect. Protein-bound drugs
are typically inactive and cannot cross cell membranes or be metabolized or excreted.
4. A drug has a half-life of 4 hours. After how many hours will the drug be considered effectively
eliminated from the body (approximately 94% eliminated)?
A) 8 hours
B) 12 hours
C) 16 hours
D) 20 hours
Correct Answer: 16 hours
Rationale: It takes approximately four to five half-lives for a drug to be effectively eliminated from the
body (about 94-97% eliminated). With a half-life of 4 hours, four half-lives would be 16 hours. After four
half-lives, the drug concentration is reduced to approximately 6.25% of the original dose.
5. Which abbreviation on a medication order indicates that the medication should be administered "as
needed"?
A) QD
B) BID
C) PRN
D) HS
, Correct Answer: PRN
Rationale: "PRN" is the abbreviation for the Latin phrase "pro re nata," meaning as needed. PRN
medications are administered when specific symptoms or conditions occur, rather than on a fixed
schedule. QD means daily, BID means twice daily, and HS means at bedtime.
6. Which route of administration yields the lowest bioavailability due to the first-pass effect?
A) Intravenous (IV)
B) Sublingual
C) Oral (PO)
D) Transdermal
Correct Answer: Oral (PO)
Rationale: Orally administered drugs are most affected by the first-pass effect. After absorption from the
GI tract, they are transported via the portal vein to the liver, where they may be extensively metabolized
before reaching systemic circulation. Intravenous, sublingual, and transdermal routes avoid first-pass
metabolism.
7. The primary site of drug metabolism in the body is the:
A) Kidneys
B) Liver
C) Lungs
D) Small intestine
Correct Answer: Liver
Rationale: The liver contains the cytochrome P-450 enzyme system responsible for biotransformation of
drugs. This enzyme system metabolizes drugs into more water-soluble compounds for excretion. The
kidneys primarily excrete drugs, while the lungs and small intestine play minor roles in metabolism.
Learning | Questions & Verified Answers | 2026 Edition
1. Which term describes what the body does to a drug, encompassing absorption, distribution,
metabolism, and excretion?
A) Pharmacodynamics
B) Pharmacokinetics
C) Pharmacotherapeutics
D) Toxicology
Correct Answer: Pharmacokinetics
Rationale: Pharmacokinetics is defined as what the body does to the drug and includes the four phases
of ADME: Absorption, Distribution, Metabolism, and Excretion. Pharmacodynamics, in contrast,
describes what the drug does to the body. Pharmacotherapeutics is the use of drugs to treat disease,
and toxicology is the study of harmful effects.
2. A medication that binds to a receptor and triggers a response is best described as a(n):
A) Antagonist
B) Agonist
C) Partial agonist
D) Inverse agonist
Correct Answer: Agonist
Rationale: An agonist binds to a receptor and triggers a response, effectively "turning on" the receptor
by mimicking the action of endogenous ligands. An antagonist binds to a receptor and blocks activation
without producing a response. A partial agonist produces a submaximal response even when all
receptors are occupied.
3. A patient is prescribed a medication that is 90% protein-bound. Which statement about this drug is
TRUE?
,A) The drug is rapidly excreted by the kidneys
B) Only 10% of the drug is pharmacologically active
C) The drug has a large volume of distribution
D) The drug is highly water-soluble
Correct Answer: Only 10% of the drug is pharmacologically active
Rationale: Only the unbound (free) fraction of a drug is pharmacologically active. A drug that is 90%
protein-bound has only 10% free drug available to produce a therapeutic effect. Protein-bound drugs
are typically inactive and cannot cross cell membranes or be metabolized or excreted.
4. A drug has a half-life of 4 hours. After how many hours will the drug be considered effectively
eliminated from the body (approximately 94% eliminated)?
A) 8 hours
B) 12 hours
C) 16 hours
D) 20 hours
Correct Answer: 16 hours
Rationale: It takes approximately four to five half-lives for a drug to be effectively eliminated from the
body (about 94-97% eliminated). With a half-life of 4 hours, four half-lives would be 16 hours. After four
half-lives, the drug concentration is reduced to approximately 6.25% of the original dose.
5. Which abbreviation on a medication order indicates that the medication should be administered "as
needed"?
A) QD
B) BID
C) PRN
D) HS
, Correct Answer: PRN
Rationale: "PRN" is the abbreviation for the Latin phrase "pro re nata," meaning as needed. PRN
medications are administered when specific symptoms or conditions occur, rather than on a fixed
schedule. QD means daily, BID means twice daily, and HS means at bedtime.
6. Which route of administration yields the lowest bioavailability due to the first-pass effect?
A) Intravenous (IV)
B) Sublingual
C) Oral (PO)
D) Transdermal
Correct Answer: Oral (PO)
Rationale: Orally administered drugs are most affected by the first-pass effect. After absorption from the
GI tract, they are transported via the portal vein to the liver, where they may be extensively metabolized
before reaching systemic circulation. Intravenous, sublingual, and transdermal routes avoid first-pass
metabolism.
7. The primary site of drug metabolism in the body is the:
A) Kidneys
B) Liver
C) Lungs
D) Small intestine
Correct Answer: Liver
Rationale: The liver contains the cytochrome P-450 enzyme system responsible for biotransformation of
drugs. This enzyme system metabolizes drugs into more water-soluble compounds for excretion. The
kidneys primarily excrete drugs, while the lungs and small intestine play minor roles in metabolism.
