NRNP 6566 MIDTERM EXAM 2026 |ADVANCED CARE OF
ADULTS IN ACUTE SETTINGS I PRACTICE QUESTIONS WITH VERIFIED
ANSWERS & DETAILED RATIONALES GRADED A+ |
WALDEN UNIVERSITY | AGACNP PROGRAM
SECTION 1: PHARMACOLOGY & PHARMACOKINETICS (Questions 1-50)
Q1. Describe the cytochrome P450 system and its role in drug metabolism.
A) A series of enzymes located in the mitochondria that metabolize medications
B) A superfamily of enzymes containing heme as a cofactor that function as
monooxygenases
C) A system of transporters that move drugs across cell membranes
D) A group of receptors that mediate drug effects at the cellular level
Correct Answer: B
Rationale: Cytochrome P450 (CYP) enzymes are a superfamily of heme-containing
enzymes that function as monooxygenases. In mammals, these proteins oxidize
steroids, fatty acids, and xenobiotics and are important for the clearance of
various compounds, as well as for hormone synthesis and breakdown. They are
primarily located in the liver endoplasmic reticulum and are responsible for the
metabolism of approximately 75% of clinically used medications.
Why the others are wrong:
A) CYP enzymes are located in the endoplasmic reticulum, not mitochondria.
Mitochondria contain CYP enzymes involved in steroidogenesis, but most drug-
metabolizing CYP enzymes are in the ER.
C) Transporters (e.g., P-glycoprotein) move drugs across membranes, but CYP
enzymes metabolize drugs through oxidation reactions.
D) Receptors mediate drug effects by binding ligands; CYP enzymes are metabolic
enzymes, not receptors.
Q2. How do CYP450 inhibitors affect drug metabolism and half-life?
1
,A) They increase enzyme activity, leading to faster drug metabolism and shorter
half-life
B) They block metabolic activity from one or more CYP450 enzymes, leading to
increased drug levels and prolonged half-life
C) They have no effect on drug metabolism
D) They increase drug excretion through the kidneys
Correct Answer: B
Rationale: CYP450 inhibitors block metabolic activity from one or more CYP
enzymes. This decreases the metabolism of drugs that are substrates for those
enzymes, leading to increased serum drug levels and prolonged half-life. This can
result in drug toxicity if doses are not adjusted. Common inhibitors include
cimetidine, ketoconazole, fluconazole, erythromycin, and grapefruit juice.
Why the others are wrong:
A) This describes the effect of CYP450 inducers, which increase enzyme activity
and shorten half-life.
C) CYP450 inhibitors have significant clinical effects on drug metabolism.
D) CYP450 inhibitors affect hepatic metabolism, not renal excretion. Excretion is
handled by the kidneys.
Q3. How do CYP450 inducers affect drug metabolism and half-life?
A) They decrease enzyme activity, leading to slower drug metabolism and longer
half-life
B) They increase CYP450 enzyme activity by increasing enzyme synthesis, leading
to faster drug metabolism and shorter half-life
C) They have no effect on drug metabolism
D) They decrease drug absorption from the GI tract
Correct Answer: B
Rationale: CYP450 inducers increase enzyme activity by increasing enzyme
synthesis. This accelerates the metabolism of drugs that are substrates for those
2
,enzymes, leading to decreased serum drug levels and shortened half-life. This can
result in therapeutic failure if doses are not adjusted. Classic inducers include
rifampin, phenytoin, carbamazepine, phenobarbital, and St. John's Wort.
Why the others are wrong:
A) This describes the effect of CYP450 inhibitors, not inducers.
C) CYP450 inducers have significant clinical effects on drug metabolism.
D) CYP450 inducers affect hepatic metabolism, not GI absorption. Absorption is
affected by other mechanisms.
Q4. The mnemonic "SICKFACES.COM" is used to remember common CYP450
inhibitors. Which of the following is correctly associated with this mnemonic?
A) S = Sertraline
B) I = Ibuprofen
C) C = Cimetidine
D) F = Furosemide
Correct Answer: C
Rationale: The mnemonic SICKFACES.COM is used to remember common
cytochrome P450 inhibitors. The components include: S = Sodium valproate, I =
Isoniazid, C = Cimetidine, K = Ketoconazole, F = Fluconazole, A = Alcohol (and
grapefruit juice), C = Chloramphenicol, E = Erythromycin, S = Sulfonamides.
Cimetidine is a well-known CYP450 inhibitor that can increase levels of warfarin,
theophylline, and phenytoin.
Why the others are wrong:
A) Sertraline is a CYP inhibitor, but the "S" in SICKFACES.COM stands for Sodium
valproate. Sertraline inhibits CYP2D6 but is not in this common mnemonic.
B) Ibuprofen is not a significant CYP450 inhibitor; the "I" stands for Isoniazid (INH).
D) Furosemide is not a CYP450 inhibitor; the "F" stands for Fluconazole.
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, Q5. Which of the following is a classic CYP450 inducer?
A) Cimetidine
B) Ketoconazole
C) Rifampin
D) Fluconazole
Correct Answer: C
Rationale: Rifampin (rifampicin) is a highly effective inducer of hepatic CYP450
enzymes. It induces CYP3A4 and other enzymes, leading to increased metabolism
of many drugs (e.g., warfarin, oral contraceptives, anticonvulsants). This can lead
to therapeutic failure if doses are not adjusted.
Why the others are wrong:
A) Cimetidine is a CYP450 inhibitor (not inducer).
B) Ketoconazole is a CYP450 inhibitor (not inducer).
D) Fluconazole is a CYP450 inhibitor (not inducer).
Q6. Describe the effect of low albumin levels on active drug levels for drugs that
are highly protein bound.
A) Low albumin levels decrease the free fraction of highly protein-bound drugs,
reducing drug effect
B) Low albumin levels increase the free fraction of highly protein-bound drugs,
potentially leading to toxicity
C) Low albumin levels have no effect on protein-bound drugs
D) Low albumin levels increase drug binding to tissues
Correct Answer: B
Rationale: Albumin is the plasma protein with the greatest capacity for binding
drugs. Highly protein-bound drugs (95-98% bound) have a narrow margin
between therapeutic and toxic effects. Low albumin levels (as seen in
malnutrition, chronic illness, or liver disease) result in fewer binding sites,
4
ADULTS IN ACUTE SETTINGS I PRACTICE QUESTIONS WITH VERIFIED
ANSWERS & DETAILED RATIONALES GRADED A+ |
WALDEN UNIVERSITY | AGACNP PROGRAM
SECTION 1: PHARMACOLOGY & PHARMACOKINETICS (Questions 1-50)
Q1. Describe the cytochrome P450 system and its role in drug metabolism.
A) A series of enzymes located in the mitochondria that metabolize medications
B) A superfamily of enzymes containing heme as a cofactor that function as
monooxygenases
C) A system of transporters that move drugs across cell membranes
D) A group of receptors that mediate drug effects at the cellular level
Correct Answer: B
Rationale: Cytochrome P450 (CYP) enzymes are a superfamily of heme-containing
enzymes that function as monooxygenases. In mammals, these proteins oxidize
steroids, fatty acids, and xenobiotics and are important for the clearance of
various compounds, as well as for hormone synthesis and breakdown. They are
primarily located in the liver endoplasmic reticulum and are responsible for the
metabolism of approximately 75% of clinically used medications.
Why the others are wrong:
A) CYP enzymes are located in the endoplasmic reticulum, not mitochondria.
Mitochondria contain CYP enzymes involved in steroidogenesis, but most drug-
metabolizing CYP enzymes are in the ER.
C) Transporters (e.g., P-glycoprotein) move drugs across membranes, but CYP
enzymes metabolize drugs through oxidation reactions.
D) Receptors mediate drug effects by binding ligands; CYP enzymes are metabolic
enzymes, not receptors.
Q2. How do CYP450 inhibitors affect drug metabolism and half-life?
1
,A) They increase enzyme activity, leading to faster drug metabolism and shorter
half-life
B) They block metabolic activity from one or more CYP450 enzymes, leading to
increased drug levels and prolonged half-life
C) They have no effect on drug metabolism
D) They increase drug excretion through the kidneys
Correct Answer: B
Rationale: CYP450 inhibitors block metabolic activity from one or more CYP
enzymes. This decreases the metabolism of drugs that are substrates for those
enzymes, leading to increased serum drug levels and prolonged half-life. This can
result in drug toxicity if doses are not adjusted. Common inhibitors include
cimetidine, ketoconazole, fluconazole, erythromycin, and grapefruit juice.
Why the others are wrong:
A) This describes the effect of CYP450 inducers, which increase enzyme activity
and shorten half-life.
C) CYP450 inhibitors have significant clinical effects on drug metabolism.
D) CYP450 inhibitors affect hepatic metabolism, not renal excretion. Excretion is
handled by the kidneys.
Q3. How do CYP450 inducers affect drug metabolism and half-life?
A) They decrease enzyme activity, leading to slower drug metabolism and longer
half-life
B) They increase CYP450 enzyme activity by increasing enzyme synthesis, leading
to faster drug metabolism and shorter half-life
C) They have no effect on drug metabolism
D) They decrease drug absorption from the GI tract
Correct Answer: B
Rationale: CYP450 inducers increase enzyme activity by increasing enzyme
synthesis. This accelerates the metabolism of drugs that are substrates for those
2
,enzymes, leading to decreased serum drug levels and shortened half-life. This can
result in therapeutic failure if doses are not adjusted. Classic inducers include
rifampin, phenytoin, carbamazepine, phenobarbital, and St. John's Wort.
Why the others are wrong:
A) This describes the effect of CYP450 inhibitors, not inducers.
C) CYP450 inducers have significant clinical effects on drug metabolism.
D) CYP450 inducers affect hepatic metabolism, not GI absorption. Absorption is
affected by other mechanisms.
Q4. The mnemonic "SICKFACES.COM" is used to remember common CYP450
inhibitors. Which of the following is correctly associated with this mnemonic?
A) S = Sertraline
B) I = Ibuprofen
C) C = Cimetidine
D) F = Furosemide
Correct Answer: C
Rationale: The mnemonic SICKFACES.COM is used to remember common
cytochrome P450 inhibitors. The components include: S = Sodium valproate, I =
Isoniazid, C = Cimetidine, K = Ketoconazole, F = Fluconazole, A = Alcohol (and
grapefruit juice), C = Chloramphenicol, E = Erythromycin, S = Sulfonamides.
Cimetidine is a well-known CYP450 inhibitor that can increase levels of warfarin,
theophylline, and phenytoin.
Why the others are wrong:
A) Sertraline is a CYP inhibitor, but the "S" in SICKFACES.COM stands for Sodium
valproate. Sertraline inhibits CYP2D6 but is not in this common mnemonic.
B) Ibuprofen is not a significant CYP450 inhibitor; the "I" stands for Isoniazid (INH).
D) Furosemide is not a CYP450 inhibitor; the "F" stands for Fluconazole.
3
, Q5. Which of the following is a classic CYP450 inducer?
A) Cimetidine
B) Ketoconazole
C) Rifampin
D) Fluconazole
Correct Answer: C
Rationale: Rifampin (rifampicin) is a highly effective inducer of hepatic CYP450
enzymes. It induces CYP3A4 and other enzymes, leading to increased metabolism
of many drugs (e.g., warfarin, oral contraceptives, anticonvulsants). This can lead
to therapeutic failure if doses are not adjusted.
Why the others are wrong:
A) Cimetidine is a CYP450 inhibitor (not inducer).
B) Ketoconazole is a CYP450 inhibitor (not inducer).
D) Fluconazole is a CYP450 inhibitor (not inducer).
Q6. Describe the effect of low albumin levels on active drug levels for drugs that
are highly protein bound.
A) Low albumin levels decrease the free fraction of highly protein-bound drugs,
reducing drug effect
B) Low albumin levels increase the free fraction of highly protein-bound drugs,
potentially leading to toxicity
C) Low albumin levels have no effect on protein-bound drugs
D) Low albumin levels increase drug binding to tissues
Correct Answer: B
Rationale: Albumin is the plasma protein with the greatest capacity for binding
drugs. Highly protein-bound drugs (95-98% bound) have a narrow margin
between therapeutic and toxic effects. Low albumin levels (as seen in
malnutrition, chronic illness, or liver disease) result in fewer binding sites,
4
