NR546 Final Exam 2026/2027 — Advanced
Pathophysiology and Pharmacology for
Nurse Practitioners Comprehensive
Practice Examination with Verified
Answers & Complete Rationales
**1. A 28-year-old patient with major depressive disorder (MDD)
has been taking sertraline 50 mg daily for 6 weeks and reports
no change in mood. What is the most appropriate next
action?**
A. Continue the current dose for another 4 weeks
B. Increase the sertraline dose
C. Switch to a different SSRI
D. Add trazodone for sleep
**Correct answer:** B. Increase the sertraline dose
**Rationale:** Sertraline's typical therapeutic dose for MDD is
100–200 mg/day. A 6-week trial at a subtherapeutic dose
warrants a dose increase before considering a switch. Serum
drug levels are not routinely used for SSRIs, and adding
trazodone is not first-line for nonresponse .
,---
**2. Which CYP450 enzyme is primarily responsible for the
metabolism of most SSRIs?**
A. CYP3A4
B. CYP1A2
C. CYP2D6
D. CYP2C19
**Correct answer:** C. CYP2D6
**Rationale:** CYP2D6 is a major pathway for many SSRIs
(fluoxetine, paroxetine, fluvoxamine) and other psychotropics.
CYP3A4 metabolizes some benzodiazepines and
antipsychotics; CYP1A2 metabolizes clozapine; CYP2C19
metabolizes citalopram and escitalopram .
---
**3. Which SSRI has the longest half-life and is least likely to
cause discontinuation syndrome?**
A. Sertraline
B. Fluvoxamine
, C. Fluoxetine
D. Paroxetine
**Correct answer:** C. Fluoxetine
**Rationale:** Fluoxetine has the longest half-life (1–2 weeks)
and an active metabolite (norfluoxetine), providing a
"forgiveness factor" if doses are missed. This makes it least
likely to cause discontinuation syndrome. Paroxetine has the
shortest half-life and is most likely to cause discontinuation
syndrome .
---
**4. Which SSRI is most likely to cause discontinuation
syndrome if abruptly stopped?**
A. Fluoxetine
B. Sertraline
C. Citalopram
D. Paroxetine
**Correct answer:** D. Paroxetine
**Rationale:** Paroxetine has a short half-life and lacks active
metabolites, making it the SSRI most likely to cause
Pathophysiology and Pharmacology for
Nurse Practitioners Comprehensive
Practice Examination with Verified
Answers & Complete Rationales
**1. A 28-year-old patient with major depressive disorder (MDD)
has been taking sertraline 50 mg daily for 6 weeks and reports
no change in mood. What is the most appropriate next
action?**
A. Continue the current dose for another 4 weeks
B. Increase the sertraline dose
C. Switch to a different SSRI
D. Add trazodone for sleep
**Correct answer:** B. Increase the sertraline dose
**Rationale:** Sertraline's typical therapeutic dose for MDD is
100–200 mg/day. A 6-week trial at a subtherapeutic dose
warrants a dose increase before considering a switch. Serum
drug levels are not routinely used for SSRIs, and adding
trazodone is not first-line for nonresponse .
,---
**2. Which CYP450 enzyme is primarily responsible for the
metabolism of most SSRIs?**
A. CYP3A4
B. CYP1A2
C. CYP2D6
D. CYP2C19
**Correct answer:** C. CYP2D6
**Rationale:** CYP2D6 is a major pathway for many SSRIs
(fluoxetine, paroxetine, fluvoxamine) and other psychotropics.
CYP3A4 metabolizes some benzodiazepines and
antipsychotics; CYP1A2 metabolizes clozapine; CYP2C19
metabolizes citalopram and escitalopram .
---
**3. Which SSRI has the longest half-life and is least likely to
cause discontinuation syndrome?**
A. Sertraline
B. Fluvoxamine
, C. Fluoxetine
D. Paroxetine
**Correct answer:** C. Fluoxetine
**Rationale:** Fluoxetine has the longest half-life (1–2 weeks)
and an active metabolite (norfluoxetine), providing a
"forgiveness factor" if doses are missed. This makes it least
likely to cause discontinuation syndrome. Paroxetine has the
shortest half-life and is most likely to cause discontinuation
syndrome .
---
**4. Which SSRI is most likely to cause discontinuation
syndrome if abruptly stopped?**
A. Fluoxetine
B. Sertraline
C. Citalopram
D. Paroxetine
**Correct answer:** D. Paroxetine
**Rationale:** Paroxetine has a short half-life and lacks active
metabolites, making it the SSRI most likely to cause
