NUR 635 ADVANCED PHARMACOLOGY EXAM READY - VERIFIED
QUESTIONS AND ANSWERS - COMPREHENSIVE LATEST VERSION
2026/2027
Q: What is the primary mechanism by which the cytochrome P450 (CYP450)
enzyme system affects drug metabolism?
ANSWER It oxidizes drugs, usually making them more water-soluble for
excretion, though it can also activate prodrugs.
Q: A drug with a high "first-pass effect" requires what dosing adjustment?
ANSWER A higher oral dose is required compared to an IV dose, because
much of the drug is metabolized by the liver before reaching systemic
circulation.
Q: Define "bioavailability."
ANSWER The fraction or percentage of an administered dose of unchanged
drug that reaches the systemic circulation.
Q: What is the mechanism of action of a "competitive agonist"?
ANSWER It binds to the receptor site and mimics the action of the
endogenous substance.
Q: How does a "non-competitive antagonist" differ from a competitive
antagonist?
ANSWER It binds to a site other than the active site (allosteric site) and
prevents receptor activation regardless of agonist concentration.
Q: What is the definition of "half-life" (
t
1/2
,)?
ANSWER The time it takes for the plasma concentration of a drug to decrease
by 50%.
Q: Why is the "therapeutic index" important in clinical practice?
ANSWER It measures the safety margin of a drug (ratio of toxic dose to
effective dose); a low index requires careful monitoring (e.g., Warfarin,
Lithium).
Q: What is "Phase I" metabolism?
ANSWER Functionalization (oxidation, reduction, hydrolysis) via CYP450
enzymes to make a drug more polar.
Q: What is "Phase II" metabolism?
ANSWER Conjugation (glucuronidation, sulfation) which makes the drug
water-soluble for renal/biliary excretion.
Q: Which drug is a potent CYP3A4 inhibitor that can lead to dangerous levels of
statins or benzodiazepines?
ANSWER Clarithromycin (or Ritonavir, Grapefruit juice).
Q: What is the "steady state" concentration?
ANSWER The point at which the amount of drug entering the body equals the
amount being eliminated; usually reached in 4–5 half-lives.
Q: Which route of administration has the fastest onset of action?
ANSWER Intravenous (IV).
Q: What is "pharmacodynamics"?
ANSWER The study of what the drug does to the body (receptor binding,
biochemical effects).
Q: What is "pharmacokinetics"?
ANSWER The study of what the body does to the drug (ADME: Absorption,
Distribution, Metabolism, Excretion).
Q: What is the result of "protein binding displacement" (e.g., Warfarin
displaced by aspirin)?
, ANSWER An increase in the free, active fraction of the displaced drug,
increasing risk of toxicity.
Q: What is "renal clearance" primarily dependent upon?
ANSWER Glomerular filtration rate (GFR).
Q: How does the "volume of distribution" (
V
d
) affect dosing?
ANSWER A high
V
d
means the drug is widely distributed into tissues (not just plasma), often
requiring a higher loading dose.
Q: What is "tolerance"?
ANSWER A reduced response to a drug over time, requiring higher doses to
achieve the same effect.
Q: Define "idiosyncrasy."
ANSWER An unexpected, genetically determined hypersensitivity or abnormal
reaction to a drug.
Q: What is the "placebo effect"?
ANSWER A beneficial effect produced by a patient's expectation of a
treatment, not the treatment itself.
Q: Which enzyme is responsible for the metabolism of alcohol (ethanol)?
ANSWER Alcohol dehydrogenase (ADH).
QUESTIONS AND ANSWERS - COMPREHENSIVE LATEST VERSION
2026/2027
Q: What is the primary mechanism by which the cytochrome P450 (CYP450)
enzyme system affects drug metabolism?
ANSWER It oxidizes drugs, usually making them more water-soluble for
excretion, though it can also activate prodrugs.
Q: A drug with a high "first-pass effect" requires what dosing adjustment?
ANSWER A higher oral dose is required compared to an IV dose, because
much of the drug is metabolized by the liver before reaching systemic
circulation.
Q: Define "bioavailability."
ANSWER The fraction or percentage of an administered dose of unchanged
drug that reaches the systemic circulation.
Q: What is the mechanism of action of a "competitive agonist"?
ANSWER It binds to the receptor site and mimics the action of the
endogenous substance.
Q: How does a "non-competitive antagonist" differ from a competitive
antagonist?
ANSWER It binds to a site other than the active site (allosteric site) and
prevents receptor activation regardless of agonist concentration.
Q: What is the definition of "half-life" (
t
1/2
,)?
ANSWER The time it takes for the plasma concentration of a drug to decrease
by 50%.
Q: Why is the "therapeutic index" important in clinical practice?
ANSWER It measures the safety margin of a drug (ratio of toxic dose to
effective dose); a low index requires careful monitoring (e.g., Warfarin,
Lithium).
Q: What is "Phase I" metabolism?
ANSWER Functionalization (oxidation, reduction, hydrolysis) via CYP450
enzymes to make a drug more polar.
Q: What is "Phase II" metabolism?
ANSWER Conjugation (glucuronidation, sulfation) which makes the drug
water-soluble for renal/biliary excretion.
Q: Which drug is a potent CYP3A4 inhibitor that can lead to dangerous levels of
statins or benzodiazepines?
ANSWER Clarithromycin (or Ritonavir, Grapefruit juice).
Q: What is the "steady state" concentration?
ANSWER The point at which the amount of drug entering the body equals the
amount being eliminated; usually reached in 4–5 half-lives.
Q: Which route of administration has the fastest onset of action?
ANSWER Intravenous (IV).
Q: What is "pharmacodynamics"?
ANSWER The study of what the drug does to the body (receptor binding,
biochemical effects).
Q: What is "pharmacokinetics"?
ANSWER The study of what the body does to the drug (ADME: Absorption,
Distribution, Metabolism, Excretion).
Q: What is the result of "protein binding displacement" (e.g., Warfarin
displaced by aspirin)?
, ANSWER An increase in the free, active fraction of the displaced drug,
increasing risk of toxicity.
Q: What is "renal clearance" primarily dependent upon?
ANSWER Glomerular filtration rate (GFR).
Q: How does the "volume of distribution" (
V
d
) affect dosing?
ANSWER A high
V
d
means the drug is widely distributed into tissues (not just plasma), often
requiring a higher loading dose.
Q: What is "tolerance"?
ANSWER A reduced response to a drug over time, requiring higher doses to
achieve the same effect.
Q: Define "idiosyncrasy."
ANSWER An unexpected, genetically determined hypersensitivity or abnormal
reaction to a drug.
Q: What is the "placebo effect"?
ANSWER A beneficial effect produced by a patient's expectation of a
treatment, not the treatment itself.
Q: Which enzyme is responsible for the metabolism of alcohol (ethanol)?
ANSWER Alcohol dehydrogenase (ADH).
