,Q1 APPLY PHARMACOKINETIC AND PHARMACODYNAMIC PRINCIPLES TO MEDICATION
ADMINISTRATION AND MONITORING
A patient with type 2 diabetes and chronic kidney disease (eGFR 35 mL/min) is
prescribed metformin. Which pharmacodynamic principle best explains the need
for dose adjustment or discontinuation?
A. Metformin undergoes extensive hepatic metabolism, and liver function is compromised in
CKD.
B. Metformin is primarily excreted unchanged by the kidneys, and accumulation increases the
risk of lactic acidosis. CORRECT
C. Metformin has a narrow therapeutic index, requiring monitoring of serum creatinine levels.
D. Metformin is a prodrug that requires renal activation to its active form.
RATIONALE: Metformin is excreted unchanged by the kidneys; impaired renal function leads to
drug accumulation and a heightened risk of lactic acidosis. Hepatic metabolism is minimal, and
metformin is not a prodrug. While it has a narrow therapeutic index, the primary concern in CKD
is renal excretion, not monitoring creatinine per se.
Q2 APPLY PHARMACOKINETIC AND PHARMACODYNAMIC PRINCIPLES TO MEDICATION
ADMINISTRATION AND MONITORING
A patient on warfarin for atrial fibrillation is prescribed amiodarone for arrhythmia
management. Which interaction best explains the need for a reduced warfarin
dose?
A. Amiodarone induces CYP2C9, increasing warfarin metabolism and reducing its effect.
B. Amiodarone inhibits CYP2C9 and CYP3A4, decreasing warfarin clearance and increasing
INR. CORRECT
C. Amiodarone displaces warfarin from protein-binding sites, increasing free warfarin acutely.
D. Amiodarone antagonizes vitamin K, potentiating warfarin's anticoagulant effect.
RATIONALE: Amiodarone is a potent inhibitor of CYP2C9 and CYP3A4, which are responsible
for warfarin metabolism. This inhibition decreases warfarin clearance, leading to elevated INR
and increased bleeding risk. Warfarin is highly protein-bound, but displacement is not the primary
mechanism. Amiodarone does not induce CYP2C9 or antagonize vitamin K.
Page 2
,Q3 APPLY PHARMACOKINETIC AND PHARMACODYNAMIC PRINCIPLES TO MEDICATION
ADMINISTRATION AND MONITORING
A patient with severe hypertension is started on intravenous nitroprusside. Which
assessment finding indicates a potential adverse effect requiring immediate
intervention?
A. Heart rate of 58 beats per minute
B. Plasma thiocyanate level of 12 mg/dL CORRECT
C. Blood pressure of 150/90 mm Hg
D. Oxygen saturation of 95% on room air
RATIONALE: Nitroprusside is metabolized to thiocyanate, which can accumulate, especially with
renal impairment. A thiocyanate level above 10 mg/dL is toxic and requires intervention.
Bradycardia, a slightly elevated BP, and normal oxygen saturation are not typical adverse effects
of nitroprusside; it can cause reflex tachycardia and hypotension.
Q4 APPLY PHARMACOKINETIC AND PHARMACODYNAMIC PRINCIPLES TO MEDICATION
ADMINISTRATION AND MONITORING
A patient receiving long-term opioid therapy for chronic pain develops new-onset
constipation. Which pharmacological approach is most appropriate for managing
this opioid-induced constipation?
A. Prescribe a stimulant laxative such as bisacodyl on an as-needed basis.
B. Add a peripherally acting mu-opioid receptor antagonist (PAMORA) such as methylnaltrexone.
CORRECT
C. Increase the opioid dose to improve tolerance to side effects.
D. Switch to a different opioid that does not cause constipation.
RATIONALE: Opioid-induced constipation is mediated by mu-opioid receptors in the gut.
PAMORAs like methylnaltrexone block these peripheral receptors without affecting central
analgesia. Stimulant laxatives are first-line but may not address the underlying mechanism.
Increasing the opioid dose worsens constipation, and all opioids cause constipation to some
degree.
Page 3
, Q5 APPLY PHARMACOKINETIC AND PHARMACODYNAMIC PRINCIPLES TO MEDICATION
ADMINISTRATION AND MONITORING
A patient with a history of asthma is prescribed propranolol for migraine
prophylaxis. What is the most critical concern regarding this prescription?
A. Propranolol may mask the symptoms of hypoglycemia.
B. Propranolol can cause bronchoconstriction via beta-2 receptor blockade. CORRECT
C. Propranolol may increase the risk of migraine triggers.
D. Propranolol can lead to orthostatic hypotension.
RATIONALE: Propranolol is a non-selective beta-blocker that blocks beta-2 receptors in the
lungs, causing bronchoconstriction and potentially exacerbating asthma. While it can mask
hypoglycemia and cause orthostatic hypotension, the most critical concern in a patient with
asthma is bronchoconstriction. Migraine prophylaxis is an approved use, but cardioselective
agents are preferred in asthma.
Q6 APPLY PHARMACOKINETIC AND PHARMACODYNAMIC PRINCIPLES TO MEDICATION
ADMINISTRATION AND MONITORING
Which laboratory value is most important to monitor for a patient on long-term
furosemide therapy for heart failure?
A. Serum creatinine
B. Serum potassium CORRECT
C. Serum calcium
D. Serum magnesium
RATIONALE: Furosemide is a loop diuretic that causes significant potassium loss, leading to
hypokalemia, which can precipitate cardiac arrhythmias. While creatinine, calcium, and
magnesium may be affected, potassium monitoring is critical due to the risk of life-threatening
arrhythmias. Hypokalemia is a common and serious adverse effect.
Page 4
ADMINISTRATION AND MONITORING
A patient with type 2 diabetes and chronic kidney disease (eGFR 35 mL/min) is
prescribed metformin. Which pharmacodynamic principle best explains the need
for dose adjustment or discontinuation?
A. Metformin undergoes extensive hepatic metabolism, and liver function is compromised in
CKD.
B. Metformin is primarily excreted unchanged by the kidneys, and accumulation increases the
risk of lactic acidosis. CORRECT
C. Metformin has a narrow therapeutic index, requiring monitoring of serum creatinine levels.
D. Metformin is a prodrug that requires renal activation to its active form.
RATIONALE: Metformin is excreted unchanged by the kidneys; impaired renal function leads to
drug accumulation and a heightened risk of lactic acidosis. Hepatic metabolism is minimal, and
metformin is not a prodrug. While it has a narrow therapeutic index, the primary concern in CKD
is renal excretion, not monitoring creatinine per se.
Q2 APPLY PHARMACOKINETIC AND PHARMACODYNAMIC PRINCIPLES TO MEDICATION
ADMINISTRATION AND MONITORING
A patient on warfarin for atrial fibrillation is prescribed amiodarone for arrhythmia
management. Which interaction best explains the need for a reduced warfarin
dose?
A. Amiodarone induces CYP2C9, increasing warfarin metabolism and reducing its effect.
B. Amiodarone inhibits CYP2C9 and CYP3A4, decreasing warfarin clearance and increasing
INR. CORRECT
C. Amiodarone displaces warfarin from protein-binding sites, increasing free warfarin acutely.
D. Amiodarone antagonizes vitamin K, potentiating warfarin's anticoagulant effect.
RATIONALE: Amiodarone is a potent inhibitor of CYP2C9 and CYP3A4, which are responsible
for warfarin metabolism. This inhibition decreases warfarin clearance, leading to elevated INR
and increased bleeding risk. Warfarin is highly protein-bound, but displacement is not the primary
mechanism. Amiodarone does not induce CYP2C9 or antagonize vitamin K.
Page 2
,Q3 APPLY PHARMACOKINETIC AND PHARMACODYNAMIC PRINCIPLES TO MEDICATION
ADMINISTRATION AND MONITORING
A patient with severe hypertension is started on intravenous nitroprusside. Which
assessment finding indicates a potential adverse effect requiring immediate
intervention?
A. Heart rate of 58 beats per minute
B. Plasma thiocyanate level of 12 mg/dL CORRECT
C. Blood pressure of 150/90 mm Hg
D. Oxygen saturation of 95% on room air
RATIONALE: Nitroprusside is metabolized to thiocyanate, which can accumulate, especially with
renal impairment. A thiocyanate level above 10 mg/dL is toxic and requires intervention.
Bradycardia, a slightly elevated BP, and normal oxygen saturation are not typical adverse effects
of nitroprusside; it can cause reflex tachycardia and hypotension.
Q4 APPLY PHARMACOKINETIC AND PHARMACODYNAMIC PRINCIPLES TO MEDICATION
ADMINISTRATION AND MONITORING
A patient receiving long-term opioid therapy for chronic pain develops new-onset
constipation. Which pharmacological approach is most appropriate for managing
this opioid-induced constipation?
A. Prescribe a stimulant laxative such as bisacodyl on an as-needed basis.
B. Add a peripherally acting mu-opioid receptor antagonist (PAMORA) such as methylnaltrexone.
CORRECT
C. Increase the opioid dose to improve tolerance to side effects.
D. Switch to a different opioid that does not cause constipation.
RATIONALE: Opioid-induced constipation is mediated by mu-opioid receptors in the gut.
PAMORAs like methylnaltrexone block these peripheral receptors without affecting central
analgesia. Stimulant laxatives are first-line but may not address the underlying mechanism.
Increasing the opioid dose worsens constipation, and all opioids cause constipation to some
degree.
Page 3
, Q5 APPLY PHARMACOKINETIC AND PHARMACODYNAMIC PRINCIPLES TO MEDICATION
ADMINISTRATION AND MONITORING
A patient with a history of asthma is prescribed propranolol for migraine
prophylaxis. What is the most critical concern regarding this prescription?
A. Propranolol may mask the symptoms of hypoglycemia.
B. Propranolol can cause bronchoconstriction via beta-2 receptor blockade. CORRECT
C. Propranolol may increase the risk of migraine triggers.
D. Propranolol can lead to orthostatic hypotension.
RATIONALE: Propranolol is a non-selective beta-blocker that blocks beta-2 receptors in the
lungs, causing bronchoconstriction and potentially exacerbating asthma. While it can mask
hypoglycemia and cause orthostatic hypotension, the most critical concern in a patient with
asthma is bronchoconstriction. Migraine prophylaxis is an approved use, but cardioselective
agents are preferred in asthma.
Q6 APPLY PHARMACOKINETIC AND PHARMACODYNAMIC PRINCIPLES TO MEDICATION
ADMINISTRATION AND MONITORING
Which laboratory value is most important to monitor for a patient on long-term
furosemide therapy for heart failure?
A. Serum creatinine
B. Serum potassium CORRECT
C. Serum calcium
D. Serum magnesium
RATIONALE: Furosemide is a loop diuretic that causes significant potassium loss, leading to
hypokalemia, which can precipitate cardiac arrhythmias. While creatinine, calcium, and
magnesium may be affected, potassium monitoring is critical due to the risk of life-threatening
arrhythmias. Hypokalemia is a common and serious adverse effect.
Page 4
