NR 566 Advanced Pharmacology
Midterm Exam Questions and Answers| Updated| Pass
Guaranteed
1. Why is sodium bicarbonate used to alkalinize the urine in salicylate (aspirin)
overdose?
A. It increases hepatic metabolism of aspirin
B. A weak acid becomes ionized in alkaline urine and is trapped there,
increasing its renal excretion
C. It blocks aspirin absorption
D. It converts aspirin to a weak base
Answer: B. A weak acid becomes ionized in alkaline urine and is trapped there,
increasing its renal excretion
Rationale: Ionized drugs are poorly reabsorbed across tubular membranes.
Alkalinizing urine traps weak acids (aspirin, phenobarbital), while acidifying urine
traps weak bases.
2. What does a large volume of distribution (Vd) indicate about a drug such as
digoxin?
A. Extensive distribution into tissues, with low concentrations remaining in
plasma
B. The drug remains confined to the plasma
C. The drug is rapidly excreted unchanged
D. The drug is completely protein bound in the blood
Answer: A. Extensive distribution into tissues, with low concentrations
remaining in plasma
Rationale: A large Vd means the drug leaves plasma for tissues, so loading doses
are larger and dialysis is less effective at removing it.
Page 1
,3. A patient on warfarin is started on another highly protein-bound drug. What
is the potential consequence?
A. Decreased free warfarin
B. Warfarin becomes inactive
C. No change can occur
D. Displacement from albumin may raise free warfarin concentration and
increase bleeding risk
Answer: D. Displacement from albumin may raise free warfarin concentration
and increase bleeding risk
Rationale: Only the unbound fraction is pharmacologically active. Displacement
interactions are clinically important mainly for narrow therapeutic index drugs
such as warfarin and phenytoin.
4. Which statement distinguishes phase I from phase II metabolism?
A. Phase I is conjugation; phase II is oxidation
B. Both are renal processes
C. Phase I reactions are mainly oxidation via cytochrome P450; phase II
reactions are conjugation (such as glucuronidation) producing water-soluble
metabolites
D. Both occur only in the intestine
Answer: C. Phase I reactions are mainly oxidation via cytochrome P450; phase II
reactions are conjugation (such as glucuronidation) producing water-soluble
metabolites
Rationale: Phase II conjugation is relatively preserved in aging and liver disease,
which is why lorazepam, oxazepam and temazepam are preferred over oxidized
benzodiazepines in these groups.
Page 2
,5. What is true of first-order elimination kinetics?
A. A constant amount is eliminated regardless of concentration
B. A constant fraction of drug is eliminated per unit time, so concentration
changes proportionally with dose
C. Elimination stops at high doses
D. Half-life varies with concentration
Answer: B. A constant fraction of drug is eliminated per unit time, so
concentration changes proportionally with dose
Rationale: Most drugs follow first-order kinetics at therapeutic doses. Phenytoin,
ethanol and high-dose aspirin follow saturable (zero-order) kinetics.
6. When should a trough drug level be drawn for a drug monitored by peak and
trough concentrations?
A. Immediately before the next scheduled dose
B. One hour after the dose
C. At the time of peak absorption
D. Randomly during the day
Answer: A. Immediately before the next scheduled dose
Rationale: Trough levels reflect the lowest concentration and are used for efficacy
and toxicity assessment. Digoxin levels are drawn at least 6 to 8 hours after a dose
to allow distribution.
7. A patient who is a CYP2D6 poor metabolizer is prescribed codeine. What is
the expected outcome?
A. Opioid toxicity from excess morphine
B. No difference from normal metabolizers
C. Immediate hepatotoxicity
D. Reduced conversion to morphine and inadequate analgesia
Page 3
, Answer: D. Reduced conversion to morphine and inadequate analgesia
Rationale: Codeine is a prodrug that CYP2D6 converts to morphine. Poor
metabolizers get little analgesia, while ultrarapid metabolizers risk toxicity.
8. Which genetic variation reduces the antiplatelet effect of clopidogrel?
A. CYP2D6 gain-of-function
B. CYP3A4 induction
C. CYP2C19 loss-of-function alleles (poor metabolizers)
D. HLA-B*1502
Answer: C. CYP2C19 loss-of-function alleles (poor metabolizers)
Rationale: Clopidogrel needs CYP2C19 for activation. Poor metabolizers have
higher rates of stent thrombosis, so an alternative P2Y12 inhibitor such as
ticagrelor may be considered.
9. Which pharmacogenomic test is recommended before starting
carbamazepine in patients of Asian ancestry?
A. HLA-B*5701
B. HLA-B*1502, due to the risk of Stevens-Johnson syndrome and toxic
epidermal necrolysis
C. TPMT
D. CYP2C9
Answer: B. HLA-B*1502, due to the risk of Stevens-Johnson syndrome and toxic
epidermal necrolysis
Rationale: HLA-B*5701 testing is used before abacavir to prevent hypersensitivity
reactions.
Page 4
Midterm Exam Questions and Answers| Updated| Pass
Guaranteed
1. Why is sodium bicarbonate used to alkalinize the urine in salicylate (aspirin)
overdose?
A. It increases hepatic metabolism of aspirin
B. A weak acid becomes ionized in alkaline urine and is trapped there,
increasing its renal excretion
C. It blocks aspirin absorption
D. It converts aspirin to a weak base
Answer: B. A weak acid becomes ionized in alkaline urine and is trapped there,
increasing its renal excretion
Rationale: Ionized drugs are poorly reabsorbed across tubular membranes.
Alkalinizing urine traps weak acids (aspirin, phenobarbital), while acidifying urine
traps weak bases.
2. What does a large volume of distribution (Vd) indicate about a drug such as
digoxin?
A. Extensive distribution into tissues, with low concentrations remaining in
plasma
B. The drug remains confined to the plasma
C. The drug is rapidly excreted unchanged
D. The drug is completely protein bound in the blood
Answer: A. Extensive distribution into tissues, with low concentrations
remaining in plasma
Rationale: A large Vd means the drug leaves plasma for tissues, so loading doses
are larger and dialysis is less effective at removing it.
Page 1
,3. A patient on warfarin is started on another highly protein-bound drug. What
is the potential consequence?
A. Decreased free warfarin
B. Warfarin becomes inactive
C. No change can occur
D. Displacement from albumin may raise free warfarin concentration and
increase bleeding risk
Answer: D. Displacement from albumin may raise free warfarin concentration
and increase bleeding risk
Rationale: Only the unbound fraction is pharmacologically active. Displacement
interactions are clinically important mainly for narrow therapeutic index drugs
such as warfarin and phenytoin.
4. Which statement distinguishes phase I from phase II metabolism?
A. Phase I is conjugation; phase II is oxidation
B. Both are renal processes
C. Phase I reactions are mainly oxidation via cytochrome P450; phase II
reactions are conjugation (such as glucuronidation) producing water-soluble
metabolites
D. Both occur only in the intestine
Answer: C. Phase I reactions are mainly oxidation via cytochrome P450; phase II
reactions are conjugation (such as glucuronidation) producing water-soluble
metabolites
Rationale: Phase II conjugation is relatively preserved in aging and liver disease,
which is why lorazepam, oxazepam and temazepam are preferred over oxidized
benzodiazepines in these groups.
Page 2
,5. What is true of first-order elimination kinetics?
A. A constant amount is eliminated regardless of concentration
B. A constant fraction of drug is eliminated per unit time, so concentration
changes proportionally with dose
C. Elimination stops at high doses
D. Half-life varies with concentration
Answer: B. A constant fraction of drug is eliminated per unit time, so
concentration changes proportionally with dose
Rationale: Most drugs follow first-order kinetics at therapeutic doses. Phenytoin,
ethanol and high-dose aspirin follow saturable (zero-order) kinetics.
6. When should a trough drug level be drawn for a drug monitored by peak and
trough concentrations?
A. Immediately before the next scheduled dose
B. One hour after the dose
C. At the time of peak absorption
D. Randomly during the day
Answer: A. Immediately before the next scheduled dose
Rationale: Trough levels reflect the lowest concentration and are used for efficacy
and toxicity assessment. Digoxin levels are drawn at least 6 to 8 hours after a dose
to allow distribution.
7. A patient who is a CYP2D6 poor metabolizer is prescribed codeine. What is
the expected outcome?
A. Opioid toxicity from excess morphine
B. No difference from normal metabolizers
C. Immediate hepatotoxicity
D. Reduced conversion to morphine and inadequate analgesia
Page 3
, Answer: D. Reduced conversion to morphine and inadequate analgesia
Rationale: Codeine is a prodrug that CYP2D6 converts to morphine. Poor
metabolizers get little analgesia, while ultrarapid metabolizers risk toxicity.
8. Which genetic variation reduces the antiplatelet effect of clopidogrel?
A. CYP2D6 gain-of-function
B. CYP3A4 induction
C. CYP2C19 loss-of-function alleles (poor metabolizers)
D. HLA-B*1502
Answer: C. CYP2C19 loss-of-function alleles (poor metabolizers)
Rationale: Clopidogrel needs CYP2C19 for activation. Poor metabolizers have
higher rates of stent thrombosis, so an alternative P2Y12 inhibitor such as
ticagrelor may be considered.
9. Which pharmacogenomic test is recommended before starting
carbamazepine in patients of Asian ancestry?
A. HLA-B*5701
B. HLA-B*1502, due to the risk of Stevens-Johnson syndrome and toxic
epidermal necrolysis
C. TPMT
D. CYP2C9
Answer: B. HLA-B*1502, due to the risk of Stevens-Johnson syndrome and toxic
epidermal necrolysis
Rationale: HLA-B*5701 testing is used before abacavir to prevent hypersensitivity
reactions.
Page 4
