Edmunds' Pharmacology for the Primary Care
Provider, 5th Edition
by Constance G. Visovsky, PhD, RN, ACNP -BC, FAAN, Cheryl H.
Zambroski, PhD, RN and Rebecca M. Lutz
,Unit 1: Principles of Pharmacology for Advanced Practice
Chapter 1: Pharmacokinetics and Pharmacodynamics
1. A 52-year-old man with hypertension and stage 3 chronic kidney disease is
prescribed lisinopril. The NP reduces the starting dose compared to patients with
normal renal function. Which pharmacokinetic principle explains this adjustment?
A. Absorption
B. Distribution
C. Metabolism
D. Excretion
ANS: D
Rationale: Lisinopril is primarily excreted unchanged by the kidneys. In patients with
impaired renal function, clearance is reduced, prolonging half-life and increasing drug
accumulation. This necessitates lower starting doses or longer dosing intervals to
prevent toxicity. Understanding excretion is crucial in pharmacokinetics because it
determines how long a drug remains active in the body.
2. A 65-year-old woman with liver cirrhosis is prescribed diazepam. The NP notes
increased sedation at standard doses. Which process is most likely impaired?
A. First-pass metabolism
B. Renal excretion
C. Gastric absorption
D. Protein binding
ANS: A
Rationale: Diazepam undergoes significant hepatic metabolism. In cirrhosis, impaired
hepatic enzyme function reduces clearance, leading to prolonged sedation and
increased risk of toxicity. First-pass metabolism is particularly important for orally
administered drugs because it reduces bioavailability; when impaired, more active drug
reaches systemic circulation.
3. A 40-year-old woman is prescribed a highly protein-bound anticoagulant. The NP
notices the patient has severe hypoalbuminemia from malnutrition. What is the greatest
risk?
A. Decreased drug effect
B. Increased free drug concentration and toxicity
C. Enhanced renal elimination
D. Reduced distribution to tissues
ANS: B
, Rationale: Protein binding acts as a reservoir, controlling the free drug fraction
available to exert effects. With low albumin, fewer binding sites are available, resulting
in higher free (active) drug levels. This significantly increases toxicity risk, particularly
with narrow therapeutic index drugs like warfarin. Advanced practice prescribers must
carefully monitor labs and adjust dosing in such patients.
4. A patient receives sublingual nitroglycerin for acute chest pain. Why is this route
superior to oral tablets in this situation?
A. Faster absorption and avoids first-pass metabolism
B. Increased renal clearance
C. Greater protein binding in plasma
D. Enhanced distribution to adipose tissue
ANS: A
Rationale: Sublingual administration allows nitroglycerin to be rapidly absorbed
through oral mucosa directly into systemic circulation, bypassing hepatic first-pass
metabolism. This provides a fast therapeutic effect, which is critical in angina
management. Oral tablets, in contrast, are extensively metabolized in the liver before
reaching effective systemic levels, delaying onset.
5. A patient with asthma requires a loading dose of theophylline. What is the purpose of
giving a loading dose?
A. To quickly achieve therapeutic plasma concentration
B. To reduce adverse effects
C. To extend half-life
D. To bypass metabolism
ANS: A
Rationale: Drugs with long half-lives, like theophylline, take longer to reach steady
state if given at maintenance doses only. A loading dose provides a higher initial
concentration, rapidly achieving therapeutic levels. This is especially important in acute
conditions where waiting multiple half-lives for effect is clinically inappropriate.
Maintenance dosing then sustains this level.
6. A 34-year-old woman on carbamazepine starts oral contraceptives. Which outcome is
most concerning?
A. Reduced contraceptive effectiveness
B. Increased contraceptive toxicity
C. Slowed contraceptive absorption
, D. Enhanced renal elimination of hormones
ANS: A
Rationale: Carbamazepine is a strong inducer of CYP3A4 enzymes. This accelerates
metabolism of ethinyl estradiol and progestins, leading to reduced plasma levels and
decreased contraceptive efficacy. Clinically, this results in unintended pregnancy risk.
NPs must counsel patients on alternative contraception when enzyme-inducing drugs
are prescribed.
7. An NP prescribes digoxin for an 80-year-old patient with reduced renal function. Why
must the dose be carefully adjusted?
A. Digoxin is eliminated primarily by the kidneys
B. Digoxin metabolism is increased with aging
C. Digoxin requires hepatic conjugation
D. Digoxin distribution is unaffected by renal function
ANS: A
Rationale: Digoxin is almost entirely cleared renally. In elderly patients with declining
GFR, drug clearance decreases, prolonging half-life and predisposing to accumulation
and toxicity (e.g., arrhythmias). Dose reductions and careful monitoring of serum digoxin
levels are essential in this population.
8. A 55-year-old man with hypertension is prescribed a beta-blocker. Two weeks later,
his resting heart rate is 56 bpm. Which pharmacodynamic mechanism explains this
effect?
A. Beta-1 receptor antagonism reduces sympathetic stimulation
B. Beta-1 receptor agonism reduces vascular tone
C. Increased renal clearance reduces catecholamines
D. Beta-2 receptor stimulation reduces HR
ANS: A
Rationale: Beta-blockers antagonize beta-1 adrenergic receptors in the heart, blunting
sympathetic effects. This leads to decreased heart rate, contractility, and cardiac output.
This pharmacodynamic effect explains both therapeutic benefit (HTN, angina,
arrhythmias) and adverse effects (bradycardia, fatigue).
9. A patient with advanced liver disease is prescribed morphine. Why is the NP
concerned about dosing?
A. Impaired hepatic metabolism prolongs drug action
B. Increased renal clearance reduces plasma levels
Provider, 5th Edition
by Constance G. Visovsky, PhD, RN, ACNP -BC, FAAN, Cheryl H.
Zambroski, PhD, RN and Rebecca M. Lutz
,Unit 1: Principles of Pharmacology for Advanced Practice
Chapter 1: Pharmacokinetics and Pharmacodynamics
1. A 52-year-old man with hypertension and stage 3 chronic kidney disease is
prescribed lisinopril. The NP reduces the starting dose compared to patients with
normal renal function. Which pharmacokinetic principle explains this adjustment?
A. Absorption
B. Distribution
C. Metabolism
D. Excretion
ANS: D
Rationale: Lisinopril is primarily excreted unchanged by the kidneys. In patients with
impaired renal function, clearance is reduced, prolonging half-life and increasing drug
accumulation. This necessitates lower starting doses or longer dosing intervals to
prevent toxicity. Understanding excretion is crucial in pharmacokinetics because it
determines how long a drug remains active in the body.
2. A 65-year-old woman with liver cirrhosis is prescribed diazepam. The NP notes
increased sedation at standard doses. Which process is most likely impaired?
A. First-pass metabolism
B. Renal excretion
C. Gastric absorption
D. Protein binding
ANS: A
Rationale: Diazepam undergoes significant hepatic metabolism. In cirrhosis, impaired
hepatic enzyme function reduces clearance, leading to prolonged sedation and
increased risk of toxicity. First-pass metabolism is particularly important for orally
administered drugs because it reduces bioavailability; when impaired, more active drug
reaches systemic circulation.
3. A 40-year-old woman is prescribed a highly protein-bound anticoagulant. The NP
notices the patient has severe hypoalbuminemia from malnutrition. What is the greatest
risk?
A. Decreased drug effect
B. Increased free drug concentration and toxicity
C. Enhanced renal elimination
D. Reduced distribution to tissues
ANS: B
, Rationale: Protein binding acts as a reservoir, controlling the free drug fraction
available to exert effects. With low albumin, fewer binding sites are available, resulting
in higher free (active) drug levels. This significantly increases toxicity risk, particularly
with narrow therapeutic index drugs like warfarin. Advanced practice prescribers must
carefully monitor labs and adjust dosing in such patients.
4. A patient receives sublingual nitroglycerin for acute chest pain. Why is this route
superior to oral tablets in this situation?
A. Faster absorption and avoids first-pass metabolism
B. Increased renal clearance
C. Greater protein binding in plasma
D. Enhanced distribution to adipose tissue
ANS: A
Rationale: Sublingual administration allows nitroglycerin to be rapidly absorbed
through oral mucosa directly into systemic circulation, bypassing hepatic first-pass
metabolism. This provides a fast therapeutic effect, which is critical in angina
management. Oral tablets, in contrast, are extensively metabolized in the liver before
reaching effective systemic levels, delaying onset.
5. A patient with asthma requires a loading dose of theophylline. What is the purpose of
giving a loading dose?
A. To quickly achieve therapeutic plasma concentration
B. To reduce adverse effects
C. To extend half-life
D. To bypass metabolism
ANS: A
Rationale: Drugs with long half-lives, like theophylline, take longer to reach steady
state if given at maintenance doses only. A loading dose provides a higher initial
concentration, rapidly achieving therapeutic levels. This is especially important in acute
conditions where waiting multiple half-lives for effect is clinically inappropriate.
Maintenance dosing then sustains this level.
6. A 34-year-old woman on carbamazepine starts oral contraceptives. Which outcome is
most concerning?
A. Reduced contraceptive effectiveness
B. Increased contraceptive toxicity
C. Slowed contraceptive absorption
, D. Enhanced renal elimination of hormones
ANS: A
Rationale: Carbamazepine is a strong inducer of CYP3A4 enzymes. This accelerates
metabolism of ethinyl estradiol and progestins, leading to reduced plasma levels and
decreased contraceptive efficacy. Clinically, this results in unintended pregnancy risk.
NPs must counsel patients on alternative contraception when enzyme-inducing drugs
are prescribed.
7. An NP prescribes digoxin for an 80-year-old patient with reduced renal function. Why
must the dose be carefully adjusted?
A. Digoxin is eliminated primarily by the kidneys
B. Digoxin metabolism is increased with aging
C. Digoxin requires hepatic conjugation
D. Digoxin distribution is unaffected by renal function
ANS: A
Rationale: Digoxin is almost entirely cleared renally. In elderly patients with declining
GFR, drug clearance decreases, prolonging half-life and predisposing to accumulation
and toxicity (e.g., arrhythmias). Dose reductions and careful monitoring of serum digoxin
levels are essential in this population.
8. A 55-year-old man with hypertension is prescribed a beta-blocker. Two weeks later,
his resting heart rate is 56 bpm. Which pharmacodynamic mechanism explains this
effect?
A. Beta-1 receptor antagonism reduces sympathetic stimulation
B. Beta-1 receptor agonism reduces vascular tone
C. Increased renal clearance reduces catecholamines
D. Beta-2 receptor stimulation reduces HR
ANS: A
Rationale: Beta-blockers antagonize beta-1 adrenergic receptors in the heart, blunting
sympathetic effects. This leads to decreased heart rate, contractility, and cardiac output.
This pharmacodynamic effect explains both therapeutic benefit (HTN, angina,
arrhythmias) and adverse effects (bradycardia, fatigue).
9. A patient with advanced liver disease is prescribed morphine. Why is the NP
concerned about dosing?
A. Impaired hepatic metabolism prolongs drug action
B. Increased renal clearance reduces plasma levels
