Pharmacology and the Nursing
Process
10th Edition
• Author(s)Linda Lane Lilley;
Shelly Rainforth Collins; Julie
S. Snyder
TEST BANK
,QUESTION 1
Item Type: MCQ
Clinical Scenario:
A 72-year-old patient with heart failure is prescribed digoxin
0.125 mg orally daily. The patient has a history of chronic kidney
disease (CKD) stage 3 with a glomerular filtration rate (GFR) of
45 mL/min. The patient's serum creatinine is 1.8 mg/dL. The
nurse reviews the medication order and the patient's laboratory
values.
Question Stem:
Which pharmacokinetic change in this patient most significantly
increases the risk for digoxin toxicity?
Answer Options:
A. Decreased gastric absorption due to age-related changes
B. Reduced drug metabolism in the liver due to decreased
hepatic blood flow
C. Decreased renal excretion due to reduced glomerular
filtration rate
D. Increased volume of distribution due to increased body fat
percentage
Correct Answer: C. Decreased renal excretion due to reduced
glomerular filtration rate
,Comprehensive Rationale:
Digoxin is primarily eliminated through the kidneys via
glomerular filtration and tubular secretion. Approximately 60-
80% of an administered dose is excreted unchanged in the
urine. In patients with CKD, the reduced GFR leads to decreased
clearance of digoxin, prolonging its half-life from the normal 36-
48 hours to up to 3-5 days. This accumulation significantly
increases the risk of digoxin toxicity, which can manifest as
nausea, vomiting, visual disturbances (yellow-green halos), and
cardiac dysrhythmias including bradycardia and atrioventricular
blocks. The therapeutic range for digoxin is narrow (0.8-2.0
ng/mL), and even small increases in serum concentration can
produce toxic effects. Age-related changes in the elderly,
including decreased lean body mass and renal function, further
compound this risk. The standard digoxin dose for older adults
with renal impairment is often reduced to 0.0625 mg daily or
every other day, with careful monitoring of serum digoxin
levels, renal function, and clinical signs of toxicity.
Distractor Analysis:
A. Decreased gastric absorption due to age-related changes:
Why It Is Incorrect: While age-related changes can affect
gastrointestinal function, including decreased gastric acid
secretion and slowed gastric emptying, digoxin absorption is
generally well-maintained in older adults. The bioavailability of
, digoxin tablets is approximately 70-80%, and age-related
changes in absorption do not present the most significant risk
for toxicity in this patient.
Common Clinical Misconception: Many nurses assume that all
pharmacokinetic processes are equally affected by aging,
leading them to focus on absorption changes when excretion
changes are more clinically significant.
Potential Medication Safety Risk: Focusing on absorption rather
than excretion could lead to overlooking the need for dose
adjustment based on renal function, potentially resulting in
digoxin accumulation and toxicity.
Appropriate Nursing Action: Assess renal function before
digoxin administration and monitor serum digoxin levels
regularly. The nurse should also assess for signs of digoxin
toxicity and educate the patient about symptoms to report.
B. Reduced drug metabolism in the liver due to decreased
hepatic blood flow:
Why It Is Incorrect: Digoxin is metabolized to a limited extent in
the liver, with only about 10-15% undergoing hepatic
metabolism. The primary route of elimination is renal excretion.
While decreased hepatic blood flow can affect metabolism of
many drugs, it is not the primary concern with digoxin.
Common Clinical Misconception: Nurses may incorrectly assume
that all medications are primarily metabolized in the liver and
Process
10th Edition
• Author(s)Linda Lane Lilley;
Shelly Rainforth Collins; Julie
S. Snyder
TEST BANK
,QUESTION 1
Item Type: MCQ
Clinical Scenario:
A 72-year-old patient with heart failure is prescribed digoxin
0.125 mg orally daily. The patient has a history of chronic kidney
disease (CKD) stage 3 with a glomerular filtration rate (GFR) of
45 mL/min. The patient's serum creatinine is 1.8 mg/dL. The
nurse reviews the medication order and the patient's laboratory
values.
Question Stem:
Which pharmacokinetic change in this patient most significantly
increases the risk for digoxin toxicity?
Answer Options:
A. Decreased gastric absorption due to age-related changes
B. Reduced drug metabolism in the liver due to decreased
hepatic blood flow
C. Decreased renal excretion due to reduced glomerular
filtration rate
D. Increased volume of distribution due to increased body fat
percentage
Correct Answer: C. Decreased renal excretion due to reduced
glomerular filtration rate
,Comprehensive Rationale:
Digoxin is primarily eliminated through the kidneys via
glomerular filtration and tubular secretion. Approximately 60-
80% of an administered dose is excreted unchanged in the
urine. In patients with CKD, the reduced GFR leads to decreased
clearance of digoxin, prolonging its half-life from the normal 36-
48 hours to up to 3-5 days. This accumulation significantly
increases the risk of digoxin toxicity, which can manifest as
nausea, vomiting, visual disturbances (yellow-green halos), and
cardiac dysrhythmias including bradycardia and atrioventricular
blocks. The therapeutic range for digoxin is narrow (0.8-2.0
ng/mL), and even small increases in serum concentration can
produce toxic effects. Age-related changes in the elderly,
including decreased lean body mass and renal function, further
compound this risk. The standard digoxin dose for older adults
with renal impairment is often reduced to 0.0625 mg daily or
every other day, with careful monitoring of serum digoxin
levels, renal function, and clinical signs of toxicity.
Distractor Analysis:
A. Decreased gastric absorption due to age-related changes:
Why It Is Incorrect: While age-related changes can affect
gastrointestinal function, including decreased gastric acid
secretion and slowed gastric emptying, digoxin absorption is
generally well-maintained in older adults. The bioavailability of
, digoxin tablets is approximately 70-80%, and age-related
changes in absorption do not present the most significant risk
for toxicity in this patient.
Common Clinical Misconception: Many nurses assume that all
pharmacokinetic processes are equally affected by aging,
leading them to focus on absorption changes when excretion
changes are more clinically significant.
Potential Medication Safety Risk: Focusing on absorption rather
than excretion could lead to overlooking the need for dose
adjustment based on renal function, potentially resulting in
digoxin accumulation and toxicity.
Appropriate Nursing Action: Assess renal function before
digoxin administration and monitor serum digoxin levels
regularly. The nurse should also assess for signs of digoxin
toxicity and educate the patient about symptoms to report.
B. Reduced drug metabolism in the liver due to decreased
hepatic blood flow:
Why It Is Incorrect: Digoxin is metabolized to a limited extent in
the liver, with only about 10-15% undergoing hepatic
metabolism. The primary route of elimination is renal excretion.
While decreased hepatic blood flow can affect metabolism of
many drugs, it is not the primary concern with digoxin.
Common Clinical Misconception: Nurses may incorrectly assume
that all medications are primarily metabolized in the liver and
