NUR612/NUR612 Exam 1 V2 | Advance
Pharmacology Q&A with Rationale |
William Paterson University
1. Which phase of pharmacokinetics is most significantly affected by a drug’s ‘first-pass effect’
when administered orally?
A. Excretion
B. Metabolism
C. Distribution
D. Absorption
Answer: B
Rationale: The first-pass effect refers to the rapid hepatic metabolism of a drug before it
reaches the systemic circulation. When drugs are absorbed from the GI tract, they enter the
portal vein and are transported directly to the liver. This can significantly reduce the
bioavailability of many oral medications compared to other routes of administration.
2. When a drug is described as having a high therapeutic index, what does this indicate about
its safety?
A. The drug is dangerous and requires frequent blood monitoring.
B. The drug is relatively safe with a wide margin between therapeutic and toxic doses.
C. The drug has a high potential for addiction and abuse.
,D. The drug is likely to cause immediate hypersensitivity reactions.
Answer: B
Rationale: The therapeutic index is the ratio between the toxic dose and the effective dose
of a medication. A high index means there is a large difference between the amount of drug
that produces a effect and the amount that is toxic. This wide margin makes the drug safer
to use in general clinical practice.
3. An agonist drug is best defined as a substance that:
A. Binds to a receptor and activates it to produce a biological response.
B. Binds to a receptor and prevents any physiological response.
C. Competes with endogenous ligands without changing cellular function.
D. Increases the metabolic rate of other drugs in the liver.
Answer: A
Rationale: Agonists are molecules that mimic the action of endogenous substances by
binding to specific receptors. Once bound, they initiate a conformational change that
triggers a cellular response. This distinguishes them from antagonists, which block
receptors without activating them.
4. What physiological change in the elderly significantly affects the distribution of highly
lipophilic drugs?
A. Decreased gastric pH
, B. Increased glomerular filtration rate
C. Increased total body fat percentage
D. Decreased liver enzyme activity
Answer: C
Rationale: As people age, their total body fat typically increases while total body water
decreases. Lipophilic or fat-soluble drugs are distributed more widely into adipose tissue in
older adults, leading to a prolonged half-life. This requires clinicians to be cautious about
cumulative toxicity in the geriatric population.
5. If a patient is taking a drug that is a known inducer of the Cytochrome P450 (CYP) enzyme
system, what is the most likely effect on a co-administered ‘substrate’ drug?
A. Increased plasma levels of the substrate drug
B. Decreased metabolism of the substrate drug
C. Decreased excretion of the substrate drug
D. Reduced therapeutic effect of the substrate drug
Answer: D
Rationale: Enzyme inducers increase the production of CYP enzymes, which accelerates
the metabolism of substrate drugs. Faster metabolism leads to lower plasma
concentrations of the substrate drug. Consequently, the patient may experience a loss of
therapeutic efficacy unless the dose is adjusted.
Pharmacology Q&A with Rationale |
William Paterson University
1. Which phase of pharmacokinetics is most significantly affected by a drug’s ‘first-pass effect’
when administered orally?
A. Excretion
B. Metabolism
C. Distribution
D. Absorption
Answer: B
Rationale: The first-pass effect refers to the rapid hepatic metabolism of a drug before it
reaches the systemic circulation. When drugs are absorbed from the GI tract, they enter the
portal vein and are transported directly to the liver. This can significantly reduce the
bioavailability of many oral medications compared to other routes of administration.
2. When a drug is described as having a high therapeutic index, what does this indicate about
its safety?
A. The drug is dangerous and requires frequent blood monitoring.
B. The drug is relatively safe with a wide margin between therapeutic and toxic doses.
C. The drug has a high potential for addiction and abuse.
,D. The drug is likely to cause immediate hypersensitivity reactions.
Answer: B
Rationale: The therapeutic index is the ratio between the toxic dose and the effective dose
of a medication. A high index means there is a large difference between the amount of drug
that produces a effect and the amount that is toxic. This wide margin makes the drug safer
to use in general clinical practice.
3. An agonist drug is best defined as a substance that:
A. Binds to a receptor and activates it to produce a biological response.
B. Binds to a receptor and prevents any physiological response.
C. Competes with endogenous ligands without changing cellular function.
D. Increases the metabolic rate of other drugs in the liver.
Answer: A
Rationale: Agonists are molecules that mimic the action of endogenous substances by
binding to specific receptors. Once bound, they initiate a conformational change that
triggers a cellular response. This distinguishes them from antagonists, which block
receptors without activating them.
4. What physiological change in the elderly significantly affects the distribution of highly
lipophilic drugs?
A. Decreased gastric pH
, B. Increased glomerular filtration rate
C. Increased total body fat percentage
D. Decreased liver enzyme activity
Answer: C
Rationale: As people age, their total body fat typically increases while total body water
decreases. Lipophilic or fat-soluble drugs are distributed more widely into adipose tissue in
older adults, leading to a prolonged half-life. This requires clinicians to be cautious about
cumulative toxicity in the geriatric population.
5. If a patient is taking a drug that is a known inducer of the Cytochrome P450 (CYP) enzyme
system, what is the most likely effect on a co-administered ‘substrate’ drug?
A. Increased plasma levels of the substrate drug
B. Decreased metabolism of the substrate drug
C. Decreased excretion of the substrate drug
D. Reduced therapeutic effect of the substrate drug
Answer: D
Rationale: Enzyme inducers increase the production of CYP enzymes, which accelerates
the metabolism of substrate drugs. Faster metabolism leads to lower plasma
concentrations of the substrate drug. Consequently, the patient may experience a loss of
therapeutic efficacy unless the dose is adjusted.
