BIO301 | BIO301 Pharmacology Exam 1 Version 1 |
Questions with Correct Answers and Expert
Explanation for Each Question | Saint Paul’s School
of Nursing
1. Which term describes the proportion of a drug that reaches the systemic circulation
in an unchanged form?
A. Bioavailability
B. Distribution
C. Metabolism
D. Excretion
Correct Answer: A
Expert Explanation: Bioavailability is a key subcategory of absorption that
measures how much active drug is available to the body. Intravenous medications
are considered 100 percent bioavailable because they enter the bloodstream
directly. Oral medications often have lower bioavailability due to the first-pass effect
in the liver. Understanding this concept helps nurses determine why different
routes require different dosages. Monitoring bioavailability ensures that the patient
receives the intended therapeutic concentration of the medication.
,2. A drug is extensively metabolized by the liver before reaching the rest of the body.
This phenomenon is known as:
A. The second-pass effect
B. Enterohepatic recirculation
C. The first-pass effect
D. Systemic clearance
Correct Answer: C
Expert Explanation: The first-pass effect occurs when a drug is absorbed from the
gastrointestinal tract and passes through the liver via the portal vein. During this
process, hepatic enzymes may metabolize a large portion of the drug before it enters
general circulation. This effect explains why oral doses are often much higher than
parenteral doses for the same medication. If the first-pass effect is too high, the drug
may be ineffective when given orally. Nurses must be aware of this to prioritize
appropriate administration routes for patients.
3. What happens to a drug that is highly protein-bound when a patient has low
albumin levels?
A. The drug becomes less effective
B. There is a lower risk of toxicity
C. There is an increase in free, active drug levels
,D. The drug is excreted more quickly
Correct Answer: C
Expert Explanation: Drugs in the bloodstream exist in a balance between being
bound to proteins and being free. Albumin is the primary protein that binds to many
acidic drugs to render them inactive. If a patient has hypoalbuminemia, fewer
binding sites are available, leading to higher concentrations of the free, active drug.
This increase in free drug significantly raises the risk of drug toxicity and side
effects. Nurses must closely monitor laboratory values like albumin to ensure
patient safety during pharmacotherapy.
4. The primary site for drug metabolism in the human body is the:
A. Kidneys
B. Small Intestine
C. Liver
D. Lungs
Correct Answer: C
Expert Explanation: Metabolism involves the chemical alteration of a drug to make
it easier for the body to excrete. The liver contains the Cytochrome P450 enzyme
system, which is responsible for most drug transformations. Changes in liver
function can drastically alter how long a drug remains active in the body. While
, kidneys are involved in excretion, they are not the primary site for chemical
metabolism. Assessing liver enzymes like AST and ALT is essential for evaluating a
patient’s metabolic capacity.
5. Which physiological process is most responsible for drug excretion?
A. Pulmonary exhalation
B. Biliary secretion
C. Sweating
D. Glomerular filtration
Correct Answer: D
Expert Explanation: Excretion is the process by which drugs and their metabolites
are removed from the body. The kidneys are the primary organ for this task,
utilizing glomerular filtration to move substances into the urine. Factors like blood
pressure and renal health directly influence the efficiency of drug removal. If renal
function is impaired, drugs can accumulate to dangerous levels in the bloodstream.
Nurses must monitor creatinine clearance and GFR to adjust dosages and prevent
renal toxicity.
6. A drug has a half-life of 4 hours. If 100 mg is administered, how much remains after
8 hours?
A. 25 mg
Questions with Correct Answers and Expert
Explanation for Each Question | Saint Paul’s School
of Nursing
1. Which term describes the proportion of a drug that reaches the systemic circulation
in an unchanged form?
A. Bioavailability
B. Distribution
C. Metabolism
D. Excretion
Correct Answer: A
Expert Explanation: Bioavailability is a key subcategory of absorption that
measures how much active drug is available to the body. Intravenous medications
are considered 100 percent bioavailable because they enter the bloodstream
directly. Oral medications often have lower bioavailability due to the first-pass effect
in the liver. Understanding this concept helps nurses determine why different
routes require different dosages. Monitoring bioavailability ensures that the patient
receives the intended therapeutic concentration of the medication.
,2. A drug is extensively metabolized by the liver before reaching the rest of the body.
This phenomenon is known as:
A. The second-pass effect
B. Enterohepatic recirculation
C. The first-pass effect
D. Systemic clearance
Correct Answer: C
Expert Explanation: The first-pass effect occurs when a drug is absorbed from the
gastrointestinal tract and passes through the liver via the portal vein. During this
process, hepatic enzymes may metabolize a large portion of the drug before it enters
general circulation. This effect explains why oral doses are often much higher than
parenteral doses for the same medication. If the first-pass effect is too high, the drug
may be ineffective when given orally. Nurses must be aware of this to prioritize
appropriate administration routes for patients.
3. What happens to a drug that is highly protein-bound when a patient has low
albumin levels?
A. The drug becomes less effective
B. There is a lower risk of toxicity
C. There is an increase in free, active drug levels
,D. The drug is excreted more quickly
Correct Answer: C
Expert Explanation: Drugs in the bloodstream exist in a balance between being
bound to proteins and being free. Albumin is the primary protein that binds to many
acidic drugs to render them inactive. If a patient has hypoalbuminemia, fewer
binding sites are available, leading to higher concentrations of the free, active drug.
This increase in free drug significantly raises the risk of drug toxicity and side
effects. Nurses must closely monitor laboratory values like albumin to ensure
patient safety during pharmacotherapy.
4. The primary site for drug metabolism in the human body is the:
A. Kidneys
B. Small Intestine
C. Liver
D. Lungs
Correct Answer: C
Expert Explanation: Metabolism involves the chemical alteration of a drug to make
it easier for the body to excrete. The liver contains the Cytochrome P450 enzyme
system, which is responsible for most drug transformations. Changes in liver
function can drastically alter how long a drug remains active in the body. While
, kidneys are involved in excretion, they are not the primary site for chemical
metabolism. Assessing liver enzymes like AST and ALT is essential for evaluating a
patient’s metabolic capacity.
5. Which physiological process is most responsible for drug excretion?
A. Pulmonary exhalation
B. Biliary secretion
C. Sweating
D. Glomerular filtration
Correct Answer: D
Expert Explanation: Excretion is the process by which drugs and their metabolites
are removed from the body. The kidneys are the primary organ for this task,
utilizing glomerular filtration to move substances into the urine. Factors like blood
pressure and renal health directly influence the efficiency of drug removal. If renal
function is impaired, drugs can accumulate to dangerous levels in the bloodstream.
Nurses must monitor creatinine clearance and GFR to adjust dosages and prevent
renal toxicity.
6. A drug has a half-life of 4 hours. If 100 mg is administered, how much remains after
8 hours?
A. 25 mg
