NAPSRX CNPR Exam Test Bank (16th Edition by
NAPSR) | Verified Questions & Answers for
Guaranteed 2025/2026 Success
1. A pharmaceutical sales representative is preparing a presentation on a new monoclonal antibody
for moderate-to-severe plaque psoriasis. The drug targets the p19 subunit of IL-23. Which of the
following best describes the mechanism of action of this class of biologics?
A. Inhibition of JAK-STAT signaling by blocking IL-23 receptor binding
B. Neutralization of IL-23, preventing differentiation of naïve T cells into Th17 cells
C. Antagonism of IL-17A, reducing neutrophil recruitment to psoriatic plaques
D. Downregulation of TNF-± production by macrophages via Fc receptor binding
Answer: B
Rationale: IL-23 p19 inhibitors (e.g., guselkumab, tildrakizumab) bind to the p19 subunit of IL-23,
preventing IL-23 from interacting with its receptor. This blocks the differentiation and maintenance of
Th17 cells, which are key in psoriasis pathogenesis. Option A is incorrect because JAK-STAT inhibition
is not the direct mechanism; IL-23 signals through JAK-STAT but the drug blocks the cytokine, not the
intracellular pathway. Option C describes IL-17 inhibitors (e.g., secukinumab). Option D describes
TNF-± inhibitors (e.g., adalimumab).
2. A patient with a history of atrial fibrillation is initiated on warfarin for stroke prevention. The
patient also requires an antibiotic for a urinary tract infection. Which of the following antibiotics
would most likely necessitate a dose reduction of warfarin due to a significant pharmacokinetic
interaction?
A. Ciprofloxacin
B. Ceftriaxone
C. Metronidazole
D. Nitrofurantoin
Answer: C
Rationale: Metronidazole is a potent inhibitor of CYP2C9, the primary enzyme that metabolizes
S-warfarin (the more active enantiomer). This inhibition increases warfarin's anticoagulant effect, often
requiring dose reduction to avoid bleeding. Ciprofloxacin also inhibits CYP1A2 and CYP3A4, but its
effect on warfarin is less predictable; however, metronidazole is more consistently associated with
significant INR elevation. Ceftriaxone and nitrofurantoin have minimal CYP interactions and are safer
choices.
Page 1
,3. A researcher is analyzing the pharmacokinetics of a novel oral anticoagulant. The drug is a
substrate of P-glycoprotein (P-gp) and is primarily metabolized by CYP3A4. Concomitant
administration of which of the following would be expected to most significantly increase the
drug's systemic exposure?
A. Rifampin, a potent CYP3A4 inducer and P-gp inducer
B. Ketoconazole, a potent CYP3A4 inhibitor and P-gp inhibitor
C. Digoxin, a P-gp substrate with no effect on CYP3A4
D. Famotidine, a histamine H2 receptor antagonist that increases gastric pH
Answer: B
Rationale: Ketoconazole inhibits both CYP3A4 and P-gp, leading to decreased metabolism and increased
absorption/accumulation of the drug, thereby markedly increasing systemic exposure. Rifampin induces
both CYP3A4 and P-gp, decreasing exposure. Digoxin is a P-gp substrate but does not inhibit the
transporter or CYP3A4; it may compete for P-gp but the effect is less pronounced than ketoconazole's
dual inhibition. Famotidine does not affect CYP3A4 or P-gp.
4. A 52-year-old patient with type 2 diabetes mellitus and established atherosclerotic
cardiovascular disease (ASCVD) is currently on metformin and atorvastatin. According to the
latest American Diabetes Association (ADA) guidelines, which of the following classes of
antihyperglycemic agents is recommended to be added to reduce major adverse cardiovascular
events (MACE) independent of glycemic control?
A. DPP-4 inhibitor
B. SGLT2 inhibitor
C. Thiazolidinedione
D. Sulfonylurea
Answer: B
Rationale: The ADA Standards of Medical Care in Diabetes (2025) recommend SGLT2 inhibitors (e.g.,
empagliflozin, dapagliflozin) or GLP-1 receptor agonists with proven cardiovascular benefit for patients
with ASCVD to reduce MACE, independent of HbA1c lowering. DPP-4 inhibitors have neutral
cardiovascular effects. Thiazolidinediones may increase heart failure risk. Sulfonylureas have no
cardiovascular benefit and may increase hypoglycemia risk.
5. A clinical trial investigates a new drug for treating opioid use disorder. The drug is a partial
agonist at mu-opioid receptors and an antagonist at kappa-opioid receptors. Which of the
following best describes the expected effects of this drug?
A. High abuse potential due to strong mu-receptor activation, with minimal withdrawal symptoms
B. Reduced cravings and relapse prevention with lower respiratory depression risk than full agonists
C. Complete blockade of all opioid effects, precipitating withdrawal in opioid-dependent individuals
D. Selective antagonism of kappa receptors with no effect on mu receptors, reducing dysphoria
Answer: B
Rationale: A mu partial agonist (like buprenorphine) provides sufficient activation to reduce cravings
and withdrawal but has a ceiling effect on respiratory depression, making it safer than full agonists.
Kappa antagonism may further reduce dysphoria and stress-induced relapse. Option A is incorrect
because partial agonists have lower abuse potential due to ceiling effects. Option C describes a full
antagonist like naltrexone. Option D ignores the mu partial agonist component.
Page 2
,6. A patient with HIV is on a stable antiretroviral regimen of tenofovir disoproxil fumarate (TDF),
emtricitabine, and dolutegravir. The patient develops chronic kidney disease (CKD) stage 3 (eGFR
50 mL/min). Which of the following regimen modifications is most appropriate according to
current DHHS guidelines?
A. Switch TDF to tenofovir alafenamide (TAF) with dose adjustment of emtricitabine
B. Discontinue dolutegravir and initiate a protease inhibitor boosted with ritonavir
C. Reduce TDF dose to 150 mg daily and continue other agents unchanged
D. Continue current regimen but monitor renal function every 6 months
Answer: A
Rationale: DHHS guidelines recommend switching TDF to TAF in patients with CKD or at risk for renal
toxicity because TAF achieves higher intracellular tenofovir levels with lower plasma exposure,
reducing renal tubular toxicity. Emtricitabine requires dose adjustment for CrCl <50 mL/min (e.g., 200
mg q24h to 200 mg q48h). Dolutegravir does not require dose adjustment. Option B is unnecessary as
dolutegravir is well-tolerated. Option C is not recommended; TDF dose reduction is not standard.
Option D would increase nephrotoxicity risk.
7. A patient with major depressive disorder has failed adequate trials of two different selective
serotonin reuptake inhibitors (SSRIs). The physician is considering augmentation with a
second-generation antipsychotic. Which of the following agents has the strongest evidence for
augmentation in treatment-resistant depression and is also FDA-approved for this indication?
A. Quetiapine
B. Aripiprazole
C. Olanzapine
D. Risperidone
Answer: B
Rationale: Aripiprazole is FDA-approved as adjunctive therapy for major depressive disorder in adults
who have not responded adequately to antidepressant monotherapy. It has the strongest evidence among
second-generation antipsychotics for this indication. Quetiapine is also FDA-approved for adjunctive
treatment of MDD (as extended-release), but aripiprazole is more commonly cited in guidelines due to
its favorable metabolic profile. Olanzapine is approved for treatment-resistant depression but only in
combination with fluoxetine (Symbyax). Risperidone is not FDA-approved for this indication.
8. A 38-year-old female with a history of migraine with aura is prescribed a triptan for acute
treatment. Which of the following statements best describes the contraindication for using triptans
in patients with a history of migraine with aura?
A. Triptans can increase the risk of ischemic stroke in patients with migraine with aura due to vasoconstriction
B. Triptans are less effective in migraine with aura because the aura phase involves cortical spreading
depression
C. Triptans may exacerbate aura symptoms by increasing serotonin release in the visual cortex
D. There is no contraindication; triptans are safe and effective for migraine with aura
Answer: A
Rationale: Migraine with aura, especially in women, is associated with an increased baseline risk of
ischemic stroke. Triptans are serotonin 5-HT1B/1D receptor agonists that cause vasoconstriction, which
could theoretically further increase stroke risk. Therefore, triptans are contraindicated in patients with a
Page 3
, history of migraine with aura, particularly those with additional risk factors. Option B is incorrect
because triptans are effective for acute treatment of migraine with aura once the headache phase begins.
Option C lacks evidence. Option D is false.
9. A patient with chronic hepatitis C (genotype 1a) is being considered for direct-acting antiviral
(DAA) therapy. The patient has compensated cirrhosis (Child-Pugh A) and is treatment-naïve.
According to the latest AASLD-IDSA guidelines, which of the following regimens is recommended
as first-line therapy?
A. Simeprevir plus sofosbuvir for 12 weeks
B. Glecaprevir/pibrentasvir for 8 weeks
C. Sofosbuvir/velpatasvir for 12 weeks
D. Elbasvir/grazoprevir for 12 weeks with ribavirin
Answer: C
Rationale: For genotype 1a with compensated cirrhosis, AASLD-IDSA guidelines recommend
sofosbuvir/velpatasvir for 12 weeks as a pangenotypic option with high efficacy.
Glecaprevir/pibrentasvir is approved for 8 weeks in non-cirrhotic patients, but in cirrhosis, it requires
12 weeks (though it is also an option). However, sofosbuvir/velpatasvir is preferred due to robust data.
Simeprevir/sofosbuvir is no longer recommended due to inferior efficacy. Elbasvir/grazoprevir is
effective but requires testing for NS5A resistance and is not preferred in cirrhosis.
10. A pharmaceutical company is developing a new drug that inhibits the enzyme dihydroorotate
dehydrogenase (DHODH). Which of the following is the most likely therapeutic indication for this
drug?
A. Hypertension
B. Rheumatoid arthritis
C. Type 2 diabetes
D. Bacterial infections
Answer: B
Rationale: DHODH is a key enzyme in the de novo pyrimidine synthesis pathway, essential for
lymphocyte proliferation. Inhibition of DHODH (e.g., by leflunomide) is used in rheumatoid arthritis to
reduce autoimmune-mediated inflammation. It is not used for hypertension, diabetes, or bacterial
infections (though some DHODH inhibitors are being explored for viral infections, the classic indication
is autoimmune disease).
11. A pharmaceutical company is developing a new drug that acts as a selective antagonist at the
²1-adrenergic receptor. Which of the following physiological effects would most likely be observed
in a clinical trial participant with no prior cardiovascular pathology?
A. Decreased heart rate and decreased myocardial contractility
B. Increased heart rate and increased bronchial smooth muscle tone
C. Decreased heart rate and increased peripheral vascular resistance
D. Increased heart rate and decreased myocardial contractility
Answer: A
Page 4
NAPSR) | Verified Questions & Answers for
Guaranteed 2025/2026 Success
1. A pharmaceutical sales representative is preparing a presentation on a new monoclonal antibody
for moderate-to-severe plaque psoriasis. The drug targets the p19 subunit of IL-23. Which of the
following best describes the mechanism of action of this class of biologics?
A. Inhibition of JAK-STAT signaling by blocking IL-23 receptor binding
B. Neutralization of IL-23, preventing differentiation of naïve T cells into Th17 cells
C. Antagonism of IL-17A, reducing neutrophil recruitment to psoriatic plaques
D. Downregulation of TNF-± production by macrophages via Fc receptor binding
Answer: B
Rationale: IL-23 p19 inhibitors (e.g., guselkumab, tildrakizumab) bind to the p19 subunit of IL-23,
preventing IL-23 from interacting with its receptor. This blocks the differentiation and maintenance of
Th17 cells, which are key in psoriasis pathogenesis. Option A is incorrect because JAK-STAT inhibition
is not the direct mechanism; IL-23 signals through JAK-STAT but the drug blocks the cytokine, not the
intracellular pathway. Option C describes IL-17 inhibitors (e.g., secukinumab). Option D describes
TNF-± inhibitors (e.g., adalimumab).
2. A patient with a history of atrial fibrillation is initiated on warfarin for stroke prevention. The
patient also requires an antibiotic for a urinary tract infection. Which of the following antibiotics
would most likely necessitate a dose reduction of warfarin due to a significant pharmacokinetic
interaction?
A. Ciprofloxacin
B. Ceftriaxone
C. Metronidazole
D. Nitrofurantoin
Answer: C
Rationale: Metronidazole is a potent inhibitor of CYP2C9, the primary enzyme that metabolizes
S-warfarin (the more active enantiomer). This inhibition increases warfarin's anticoagulant effect, often
requiring dose reduction to avoid bleeding. Ciprofloxacin also inhibits CYP1A2 and CYP3A4, but its
effect on warfarin is less predictable; however, metronidazole is more consistently associated with
significant INR elevation. Ceftriaxone and nitrofurantoin have minimal CYP interactions and are safer
choices.
Page 1
,3. A researcher is analyzing the pharmacokinetics of a novel oral anticoagulant. The drug is a
substrate of P-glycoprotein (P-gp) and is primarily metabolized by CYP3A4. Concomitant
administration of which of the following would be expected to most significantly increase the
drug's systemic exposure?
A. Rifampin, a potent CYP3A4 inducer and P-gp inducer
B. Ketoconazole, a potent CYP3A4 inhibitor and P-gp inhibitor
C. Digoxin, a P-gp substrate with no effect on CYP3A4
D. Famotidine, a histamine H2 receptor antagonist that increases gastric pH
Answer: B
Rationale: Ketoconazole inhibits both CYP3A4 and P-gp, leading to decreased metabolism and increased
absorption/accumulation of the drug, thereby markedly increasing systemic exposure. Rifampin induces
both CYP3A4 and P-gp, decreasing exposure. Digoxin is a P-gp substrate but does not inhibit the
transporter or CYP3A4; it may compete for P-gp but the effect is less pronounced than ketoconazole's
dual inhibition. Famotidine does not affect CYP3A4 or P-gp.
4. A 52-year-old patient with type 2 diabetes mellitus and established atherosclerotic
cardiovascular disease (ASCVD) is currently on metformin and atorvastatin. According to the
latest American Diabetes Association (ADA) guidelines, which of the following classes of
antihyperglycemic agents is recommended to be added to reduce major adverse cardiovascular
events (MACE) independent of glycemic control?
A. DPP-4 inhibitor
B. SGLT2 inhibitor
C. Thiazolidinedione
D. Sulfonylurea
Answer: B
Rationale: The ADA Standards of Medical Care in Diabetes (2025) recommend SGLT2 inhibitors (e.g.,
empagliflozin, dapagliflozin) or GLP-1 receptor agonists with proven cardiovascular benefit for patients
with ASCVD to reduce MACE, independent of HbA1c lowering. DPP-4 inhibitors have neutral
cardiovascular effects. Thiazolidinediones may increase heart failure risk. Sulfonylureas have no
cardiovascular benefit and may increase hypoglycemia risk.
5. A clinical trial investigates a new drug for treating opioid use disorder. The drug is a partial
agonist at mu-opioid receptors and an antagonist at kappa-opioid receptors. Which of the
following best describes the expected effects of this drug?
A. High abuse potential due to strong mu-receptor activation, with minimal withdrawal symptoms
B. Reduced cravings and relapse prevention with lower respiratory depression risk than full agonists
C. Complete blockade of all opioid effects, precipitating withdrawal in opioid-dependent individuals
D. Selective antagonism of kappa receptors with no effect on mu receptors, reducing dysphoria
Answer: B
Rationale: A mu partial agonist (like buprenorphine) provides sufficient activation to reduce cravings
and withdrawal but has a ceiling effect on respiratory depression, making it safer than full agonists.
Kappa antagonism may further reduce dysphoria and stress-induced relapse. Option A is incorrect
because partial agonists have lower abuse potential due to ceiling effects. Option C describes a full
antagonist like naltrexone. Option D ignores the mu partial agonist component.
Page 2
,6. A patient with HIV is on a stable antiretroviral regimen of tenofovir disoproxil fumarate (TDF),
emtricitabine, and dolutegravir. The patient develops chronic kidney disease (CKD) stage 3 (eGFR
50 mL/min). Which of the following regimen modifications is most appropriate according to
current DHHS guidelines?
A. Switch TDF to tenofovir alafenamide (TAF) with dose adjustment of emtricitabine
B. Discontinue dolutegravir and initiate a protease inhibitor boosted with ritonavir
C. Reduce TDF dose to 150 mg daily and continue other agents unchanged
D. Continue current regimen but monitor renal function every 6 months
Answer: A
Rationale: DHHS guidelines recommend switching TDF to TAF in patients with CKD or at risk for renal
toxicity because TAF achieves higher intracellular tenofovir levels with lower plasma exposure,
reducing renal tubular toxicity. Emtricitabine requires dose adjustment for CrCl <50 mL/min (e.g., 200
mg q24h to 200 mg q48h). Dolutegravir does not require dose adjustment. Option B is unnecessary as
dolutegravir is well-tolerated. Option C is not recommended; TDF dose reduction is not standard.
Option D would increase nephrotoxicity risk.
7. A patient with major depressive disorder has failed adequate trials of two different selective
serotonin reuptake inhibitors (SSRIs). The physician is considering augmentation with a
second-generation antipsychotic. Which of the following agents has the strongest evidence for
augmentation in treatment-resistant depression and is also FDA-approved for this indication?
A. Quetiapine
B. Aripiprazole
C. Olanzapine
D. Risperidone
Answer: B
Rationale: Aripiprazole is FDA-approved as adjunctive therapy for major depressive disorder in adults
who have not responded adequately to antidepressant monotherapy. It has the strongest evidence among
second-generation antipsychotics for this indication. Quetiapine is also FDA-approved for adjunctive
treatment of MDD (as extended-release), but aripiprazole is more commonly cited in guidelines due to
its favorable metabolic profile. Olanzapine is approved for treatment-resistant depression but only in
combination with fluoxetine (Symbyax). Risperidone is not FDA-approved for this indication.
8. A 38-year-old female with a history of migraine with aura is prescribed a triptan for acute
treatment. Which of the following statements best describes the contraindication for using triptans
in patients with a history of migraine with aura?
A. Triptans can increase the risk of ischemic stroke in patients with migraine with aura due to vasoconstriction
B. Triptans are less effective in migraine with aura because the aura phase involves cortical spreading
depression
C. Triptans may exacerbate aura symptoms by increasing serotonin release in the visual cortex
D. There is no contraindication; triptans are safe and effective for migraine with aura
Answer: A
Rationale: Migraine with aura, especially in women, is associated with an increased baseline risk of
ischemic stroke. Triptans are serotonin 5-HT1B/1D receptor agonists that cause vasoconstriction, which
could theoretically further increase stroke risk. Therefore, triptans are contraindicated in patients with a
Page 3
, history of migraine with aura, particularly those with additional risk factors. Option B is incorrect
because triptans are effective for acute treatment of migraine with aura once the headache phase begins.
Option C lacks evidence. Option D is false.
9. A patient with chronic hepatitis C (genotype 1a) is being considered for direct-acting antiviral
(DAA) therapy. The patient has compensated cirrhosis (Child-Pugh A) and is treatment-naïve.
According to the latest AASLD-IDSA guidelines, which of the following regimens is recommended
as first-line therapy?
A. Simeprevir plus sofosbuvir for 12 weeks
B. Glecaprevir/pibrentasvir for 8 weeks
C. Sofosbuvir/velpatasvir for 12 weeks
D. Elbasvir/grazoprevir for 12 weeks with ribavirin
Answer: C
Rationale: For genotype 1a with compensated cirrhosis, AASLD-IDSA guidelines recommend
sofosbuvir/velpatasvir for 12 weeks as a pangenotypic option with high efficacy.
Glecaprevir/pibrentasvir is approved for 8 weeks in non-cirrhotic patients, but in cirrhosis, it requires
12 weeks (though it is also an option). However, sofosbuvir/velpatasvir is preferred due to robust data.
Simeprevir/sofosbuvir is no longer recommended due to inferior efficacy. Elbasvir/grazoprevir is
effective but requires testing for NS5A resistance and is not preferred in cirrhosis.
10. A pharmaceutical company is developing a new drug that inhibits the enzyme dihydroorotate
dehydrogenase (DHODH). Which of the following is the most likely therapeutic indication for this
drug?
A. Hypertension
B. Rheumatoid arthritis
C. Type 2 diabetes
D. Bacterial infections
Answer: B
Rationale: DHODH is a key enzyme in the de novo pyrimidine synthesis pathway, essential for
lymphocyte proliferation. Inhibition of DHODH (e.g., by leflunomide) is used in rheumatoid arthritis to
reduce autoimmune-mediated inflammation. It is not used for hypertension, diabetes, or bacterial
infections (though some DHODH inhibitors are being explored for viral infections, the classic indication
is autoimmune disease).
11. A pharmaceutical company is developing a new drug that acts as a selective antagonist at the
²1-adrenergic receptor. Which of the following physiological effects would most likely be observed
in a clinical trial participant with no prior cardiovascular pathology?
A. Decreased heart rate and decreased myocardial contractility
B. Increased heart rate and increased bronchial smooth muscle tone
C. Decreased heart rate and increased peripheral vascular resistance
D. Increased heart rate and decreased myocardial contractility
Answer: A
Page 4
