Regis College – MSN/FNP Program
Module I: Foundations of Clinical Pharmacology (Questions 1-6)
Q1: A patient is prescribed fluoxetine (Prozac) for depression and then started on metoprolol
for hypertension. The patient reports increased fatigue and lightheadedness. Fluoxetine is a
strong CYP2D6 inhibitor. Which statement BEST explains this interaction?
A. Fluoxetine increases metoprolol metabolism, reducing its effect
B. Fluoxetine inhibits metoprolol metabolism, increasing its effect and adverse effects
[CORRECT]
C. Metoprolol induces fluoxetine metabolism, reducing antidepressant effect
D. There is no significant interaction between these medications
Correct Answer: B
Rationale: Fluoxetine is a potent CYP2D6 inhibitor. Metoprolol is metabolized by CYP2D6.
Inhibition decreases metoprolol clearance, increasing serum levels, leading to enhanced beta-
blockade (bradycardia, fatigue). Common error: assuming all antidepressants are safe with
beta-blockers. Clinical pearl: Consider carvedilol (multiple CYP pathways) or alternative
antidepressant (bupropion, not a strong CYP2D6 inhibitor).
Q2: A provider prescribes sirolimus for a patient post-kidney transplant. The patient is already
taking ketoconazole for a fungal infection. What is the most appropriate action regarding the
sirolimus dose?
A. Increase sirolimus dose by 50% due to decreased absorption
B. Decrease sirolimus dose to one-third of the original dose [CORRECT]
C. No change is needed; they act on different metabolic pathways
D. Separate administration by 2 hours to avoid chelation in the gut
Correct Answer: B
Rationale: Ketoconazole is a strong CYP3A4 inhibitor. Sirolimus is a CYP3A4 substrate.
Concurrent use dramatically increases sirolimus levels, risking severe toxicity. Guidelines
recommend reducing the sirolimus dose to 1/3 of the original dose. Common error: assuming
,no interaction or separating doses. Clinical pearl: Avoid CYP3A4 inhibitors with sirolimus if
possible; if unavoidable, therapeutic drug monitoring is mandatory.
Q3: A 45-year-old patient with depression is prescribed amitriptyline but reports no
improvement in mood after 6 weeks at a therapeutic dose. Genetic testing reveals the patient
is a CYP2D6 ultra-rapid metabolizer. Which action is MOST appropriate?
A. Add a CYP2D6 inhibitor to boost amitriptyline levels
B. Switch to a non-CYP2D6 metabolized antidepressant like sertraline [CORRECT]
C. Increase the amitriptyline dose to maximum and recheck in 2 weeks
D. Add a second antidepressant for synergy
Correct Answer: B
Rationale: Ultra-rapid metabolizers metabolize CYP2D6 substrates too quickly, leading to
subtherapeutic levels and treatment failure. The safest approach is switching to a drug not
primarily metabolized by CYP2D6. Common error: adding inhibitors or maximizing doses,
which increases side effect risks unpredictably. Clinical pearl: Pharmacogenomic testing (like
CYP2D6 and CYP2C19) is recommended by CPIC for TCA prescribing to avoid therapeutic
failures or toxicity.
Q4: A drug with a half-life of 12 hours is administered by continuous intravenous infusion.
Approximately how long will it take to reach steady-state?
A. 12 hours
B. 24 hours
C. 60 hours [CORRECT]
D. 96 hours
Correct Answer: C
Rationale: Steady-state is reached in approximately 4 to 5 half-lives. 5 x 12 hours = 60 hours.
Common error: guessing 1-2 half-lives. Clinical pearl: For drugs with long half-lives (e.g.,
fluoxetine, amiodarone), it takes weeks to reach steady-state or wash out, impacting clinical
decisions when switching drugs or evaluating efficacy.
,Q5: A patient is taking a medication with a narrow therapeutic index. Which
pharmacodynamic concept is MOST critical for the prescriber to consider?
A. Bioavailability
B. First-pass metabolism
C. The ratio of toxic dose to effective dose [CORRECT]
D. Volume of distribution
Correct Answer: C
Rationale: The therapeutic index (TI) is the ratio of the toxic dose (TD50) to the effective dose
(ED50). A narrow TI means the dose required for toxicity is close to the dose required for
efficacy (e.g., warfarin, lithium, digoxin), requiring close monitoring. Common error: confusing
PK (bioavailability, Vd) with PD (TI). Clinical pearl: Drugs with narrow TIs require serum drug
monitoring and careful dose adjustments.
Q6: A patient with variceal bleeding is given intravenous octreotide. The provider
understands this drug causes vasoconstriction of the splanchnic circulation. This is an example
of which pharmacodynamic mechanism?
A. Competitive antagonist
B. Partial agonist
C. Direct agonist at somatostatin receptors [CORRECT]
D. Non-competitive antagonist
Correct Answer: C
Rationale: Octreotide is a somatostatin analog that acts as a direct agonist at somatostatin
receptors, causing vasoconstriction and reducing portal pressure. Common error: confusing
agonists with antagonists. Clinical pearl: Agonists mimic endogenous substances
(somatostatin), whereas antagonists block them (e.g., naloxone blocking mu-opioid
receptors).
Module II: Cardiovascular Pharmacology (Questions 7-20)
Q7: A 68-year-old patient with HFrEF (LVEF 30%) is currently on carvedilol 25mg BID, lisinopril
20mg daily, and furosemide 40mg daily. According to 2024 ACC/AHA guidelines, which
, medication should be added to reduce cardiovascular mortality and heart failure
hospitalizations?
A. Digoxin 0.125mg daily
B. Spironolactone 25mg daily [CORRECT]
C. Hydralazine 75mg TID + isosorbide dinitrate 40mg TID
D. Diltiazem 180mg daily
Correct Answer: B
Rationale: Aldosterone antagonists (spironolactone, eplerenone) reduce mortality and HF
hospitalizations in HFrEF (RALES, EMPHASIS-HF). Digoxin (A) reduces hospitalizations only.
Hydralazine/ISDN (C) has mortality benefit primarily in self-identified Black patients. Non-DHP
CCBs (D) are contraindicated in HFrEF.
Q8: A 72-year-old patient with non-valvular atrial fibrillation and CHA₂DS₂-VASc score of 4 is
started on apixaban 5mg BID. Which statement regarding DOAC monitoring is CORRECT?
A. INR should be maintained between 2.0-3.0
B. Routine coagulation monitoring is not required [CORRECT]
C. aPTT should be checked monthly
D. Drug levels should be drawn every 3 months
Correct Answer: B
Rationale: DOACs have predictable pharmacokinetics and do not require routine coagulation
monitoring (unlike warfarin). Common error: applying warfarin monitoring rules to DOACs.
Clinical pearl: Apixaban has lower major bleeding risk compared to warfarin. Reversal agent
for life-threatening bleeding: andexanet alfa.
Q9: A patient with atrial fibrillation on rivaroxaban requires urgent surgery for a hip fracture.
The surgery cannot be delayed. Which reversal agent should be administered?
A. Protamine sulfate
B. Idarucizumab
C. Andexanet alfa [CORRECT]