Advanced Pharmacology NSG 533 —
Comprehensive Practice Exam & Study
Guide 2026–2027 | Updated
Pharmacology Questions, Detailed
Answers, Explanations & In-Depth
Rationales
1. A patient taking fluoxetine for major depressive disorder
is being switched to phenelzine. Which pharmacokinetic
characteristic of fluoxetine is most important when
determining the timing of the switch?
A. It has negligible protein binding.
B. It is primarily eliminated unchanged through the kidneys.
C. It has a long half-life and an active metabolite that persists
in the body.
D. It undergoes complete first-pass metabolism.
Answer: C. It has a long half-life and an active metabolite
that persists in the body.
Rationale: Fluoxetine and its active metabolite norfluoxetine
have relatively long half-lives. Residual serotonergic activity
can persist after discontinuation, increasing the risk of
serotonin syndrome if a monoamine oxidase inhibitor is
,started too soon. A prolonged washout period is therefore
required.
2. A patient with hypertension and type 2 diabetes is
prescribed an ACE inhibitor. Which laboratory abnormality
requires the greatest concern after therapy is initiated?
A. Sodium of 138 mEq/L
B. Potassium of 5.8 mEq/L
C. Chloride of 101 mEq/L
D. Calcium of 9.4 mg/dL
Answer: B. Potassium of 5.8 mEq/L
Rationale: ACE inhibitors reduce angiotensin II formation and
consequently decrease aldosterone secretion. Reduced
aldosterone can decrease potassium excretion, producing
hyperkalemia. A potassium level of 5.8 mEq/L is clinically
significant and requires prompt evaluation, particularly in
patients with renal impairment or other medications that
raise potassium.
3. A patient taking warfarin begins trimethoprim-
sulfamethoxazole for a bacterial infection. Which change is
most likely to occur?
A. Decreased INR because of increased vitamin K synthesis
B. Increased INR and increased bleeding risk
C. Decreased warfarin absorption without an INR change
D. Increased platelet production
,Answer: B. Increased INR and increased bleeding risk
Rationale: Trimethoprim-sulfamethoxazole can increase the
anticoagulant effect of warfarin through metabolic inhibition
and other mechanisms. The resulting increase in
anticoagulation can substantially elevate INR and bleeding
risk. Patients receiving this combination require careful
anticoagulation monitoring and clinical assessment.
4. A patient with major depressive disorder has taken
sertraline at a therapeutic dose for 10 weeks with
inadequate improvement. Which pharmacotherapeutic
principle is most appropriate before simply continuing the
same regimen indefinitely?
A. Antidepressants should always be discontinued after 4
weeks.
B. The diagnosis, adherence, dose adequacy, comorbidities,
and treatment response should be reassessed.
C. Two antidepressants from the same class should
automatically be combined.
D. The dose should always be doubled regardless of the
medication.
Answer: B. The diagnosis, adherence, dose adequacy,
comorbidities, and treatment response should be
reassessed.
Rationale: Apparent treatment resistance requires systematic
reassessment. Clinicians should verify adherence, duration,
therapeutic dosing, diagnosis, substance use, comorbid
, psychiatric or medical disorders, and potential interactions
before switching, augmenting, or otherwise modifying
therapy. Automatic dose escalation or combination therapy is
not appropriate without clinical justification.
5. A patient taking lithium develops vomiting, coarse
tremor, ataxia, and confusion. Which medication exposure
would be particularly concerning because it can increase
lithium concentrations?
A. Acetaminophen
B. Hydrochlorothiazide
C. Amoxicillin
D. Famotidine
Answer: B. Hydrochlorothiazide
Rationale: Thiazide diuretics decrease renal sodium
reabsorption and can increase proximal renal sodium—and
lithium—reabsorption. This may significantly increase serum
lithium concentrations and precipitate toxicity. Coarse tremor,
gastrointestinal symptoms, ataxia, and altered mental status
are concerning manifestations of lithium toxicity.
6. A patient taking clopidogrel has a genetic variant resulting
in markedly reduced CYP2C19 activity. What is the primary
pharmacologic concern?
A. Excessive conversion of clopidogrel to its active metabolite
B. Reduced formation of the active metabolite and
Comprehensive Practice Exam & Study
Guide 2026–2027 | Updated
Pharmacology Questions, Detailed
Answers, Explanations & In-Depth
Rationales
1. A patient taking fluoxetine for major depressive disorder
is being switched to phenelzine. Which pharmacokinetic
characteristic of fluoxetine is most important when
determining the timing of the switch?
A. It has negligible protein binding.
B. It is primarily eliminated unchanged through the kidneys.
C. It has a long half-life and an active metabolite that persists
in the body.
D. It undergoes complete first-pass metabolism.
Answer: C. It has a long half-life and an active metabolite
that persists in the body.
Rationale: Fluoxetine and its active metabolite norfluoxetine
have relatively long half-lives. Residual serotonergic activity
can persist after discontinuation, increasing the risk of
serotonin syndrome if a monoamine oxidase inhibitor is
,started too soon. A prolonged washout period is therefore
required.
2. A patient with hypertension and type 2 diabetes is
prescribed an ACE inhibitor. Which laboratory abnormality
requires the greatest concern after therapy is initiated?
A. Sodium of 138 mEq/L
B. Potassium of 5.8 mEq/L
C. Chloride of 101 mEq/L
D. Calcium of 9.4 mg/dL
Answer: B. Potassium of 5.8 mEq/L
Rationale: ACE inhibitors reduce angiotensin II formation and
consequently decrease aldosterone secretion. Reduced
aldosterone can decrease potassium excretion, producing
hyperkalemia. A potassium level of 5.8 mEq/L is clinically
significant and requires prompt evaluation, particularly in
patients with renal impairment or other medications that
raise potassium.
3. A patient taking warfarin begins trimethoprim-
sulfamethoxazole for a bacterial infection. Which change is
most likely to occur?
A. Decreased INR because of increased vitamin K synthesis
B. Increased INR and increased bleeding risk
C. Decreased warfarin absorption without an INR change
D. Increased platelet production
,Answer: B. Increased INR and increased bleeding risk
Rationale: Trimethoprim-sulfamethoxazole can increase the
anticoagulant effect of warfarin through metabolic inhibition
and other mechanisms. The resulting increase in
anticoagulation can substantially elevate INR and bleeding
risk. Patients receiving this combination require careful
anticoagulation monitoring and clinical assessment.
4. A patient with major depressive disorder has taken
sertraline at a therapeutic dose for 10 weeks with
inadequate improvement. Which pharmacotherapeutic
principle is most appropriate before simply continuing the
same regimen indefinitely?
A. Antidepressants should always be discontinued after 4
weeks.
B. The diagnosis, adherence, dose adequacy, comorbidities,
and treatment response should be reassessed.
C. Two antidepressants from the same class should
automatically be combined.
D. The dose should always be doubled regardless of the
medication.
Answer: B. The diagnosis, adherence, dose adequacy,
comorbidities, and treatment response should be
reassessed.
Rationale: Apparent treatment resistance requires systematic
reassessment. Clinicians should verify adherence, duration,
therapeutic dosing, diagnosis, substance use, comorbid
, psychiatric or medical disorders, and potential interactions
before switching, augmenting, or otherwise modifying
therapy. Automatic dose escalation or combination therapy is
not appropriate without clinical justification.
5. A patient taking lithium develops vomiting, coarse
tremor, ataxia, and confusion. Which medication exposure
would be particularly concerning because it can increase
lithium concentrations?
A. Acetaminophen
B. Hydrochlorothiazide
C. Amoxicillin
D. Famotidine
Answer: B. Hydrochlorothiazide
Rationale: Thiazide diuretics decrease renal sodium
reabsorption and can increase proximal renal sodium—and
lithium—reabsorption. This may significantly increase serum
lithium concentrations and precipitate toxicity. Coarse tremor,
gastrointestinal symptoms, ataxia, and altered mental status
are concerning manifestations of lithium toxicity.
6. A patient taking clopidogrel has a genetic variant resulting
in markedly reduced CYP2C19 activity. What is the primary
pharmacologic concern?
A. Excessive conversion of clopidogrel to its active metabolite
B. Reduced formation of the active metabolite and
