Lehne's Pharmacology for Nursing
Care
12th Edition
• Author(s)Jacqueline Rosenjack
Burchum; Laura D. Rosenthal
,TEST BANK
QUESTION 1
Type: MCQ
Clinical Scenario:
A 68-year-old patient with chronic heart failure is prescribed a
new medication that acts as a partial agonist at beta-1
adrenergic receptors. The patient asks the nurse, "Will this
medication work as well as the full agonist I was taking before?"
Question Stem:
Which response by the nurse most accurately explains the
pharmacodynamic difference between a partial agonist and a
full agonist?
Answer Options:
A. "A partial agonist produces a greater maximal response than
a full agonist at the same receptor."
B. "A partial agonist produces a submaximal response even
when all receptors are occupied."
C. "A partial agonist has higher potency than a full agonist at
the same receptor."
D. "A partial agonist produces the same maximal effect but
requires higher doses."
,Correct Answer: B
Detailed Rationale:
The correct answer is B because it accurately describes the
pharmacodynamic property of partial agonists. A partial agonist
binds to the same receptor as a full agonist but produces a
lower maximal response (intrinsic activity between 0 and 1),
even when all receptors are occupied. This is due to the partial
agonist's lower intrinsic activity compared to full agonists. This
property is clinically significant in heart failure management
because partial agonists like carvedilol provide beneficial beta-
blockade while maintaining some sympathetic tone, reducing
the risk of excessive bradycardia and worsening heart failure.
Understanding this concept is essential for nurses to explain the
therapeutic effects and expected outcomes of partial agonist
therapy to patients.
Incorrect Option Analysis:
A. Why It Is Incorrect: This statement is factually incorrect. Full
agonists produce the greatest possible maximal response at a
given receptor. Partial agonists, by definition, cannot achieve
the same maximal response even when all receptors are
occupied due to their lower intrinsic activity.
Common Clinical Misconception: Patients and nurses may
assume that if a drug binds to the same receptor, it must
produce the same effect. This misunderstanding can lead to
, unrealistic expectations of therapeutic outcomes.
Potential Medication Safety Risk: If the patient expects the
partial agonist to have the same effect as the full agonist, they
may become non-adherent when they don't experience the
same level of symptom relief, leading to worsening heart
failure.
Appropriate Nursing Consideration: Educate patients that
although partial agonists bind to the same receptors, their
effects are more moderate and often safer for chronic
conditions.
C. Why It Is Incorrect: Potency (the dose required to produce a
given effect) is a separate concept from maximal efficacy. A
partial agonist can be more potent than a full agonist (lower
ED50) while still having lower maximal efficacy. Potency does
not predict efficacy.
Common Clinical Misconception: The terms "potency" and
"efficacy" are often confused in clinical practice. A more potent
drug is not necessarily more effective.
Potential Medication Safety Risk: Misunderstanding potency
could lead to incorrect dosing decisions. The nurse might
incorrectly assume a more potent partial agonist requires
higher doses to achieve effectiveness.
Appropriate Nursing Consideration: Use the dose-response
curve to teach patients about the difference between how
Care
12th Edition
• Author(s)Jacqueline Rosenjack
Burchum; Laura D. Rosenthal
,TEST BANK
QUESTION 1
Type: MCQ
Clinical Scenario:
A 68-year-old patient with chronic heart failure is prescribed a
new medication that acts as a partial agonist at beta-1
adrenergic receptors. The patient asks the nurse, "Will this
medication work as well as the full agonist I was taking before?"
Question Stem:
Which response by the nurse most accurately explains the
pharmacodynamic difference between a partial agonist and a
full agonist?
Answer Options:
A. "A partial agonist produces a greater maximal response than
a full agonist at the same receptor."
B. "A partial agonist produces a submaximal response even
when all receptors are occupied."
C. "A partial agonist has higher potency than a full agonist at
the same receptor."
D. "A partial agonist produces the same maximal effect but
requires higher doses."
,Correct Answer: B
Detailed Rationale:
The correct answer is B because it accurately describes the
pharmacodynamic property of partial agonists. A partial agonist
binds to the same receptor as a full agonist but produces a
lower maximal response (intrinsic activity between 0 and 1),
even when all receptors are occupied. This is due to the partial
agonist's lower intrinsic activity compared to full agonists. This
property is clinically significant in heart failure management
because partial agonists like carvedilol provide beneficial beta-
blockade while maintaining some sympathetic tone, reducing
the risk of excessive bradycardia and worsening heart failure.
Understanding this concept is essential for nurses to explain the
therapeutic effects and expected outcomes of partial agonist
therapy to patients.
Incorrect Option Analysis:
A. Why It Is Incorrect: This statement is factually incorrect. Full
agonists produce the greatest possible maximal response at a
given receptor. Partial agonists, by definition, cannot achieve
the same maximal response even when all receptors are
occupied due to their lower intrinsic activity.
Common Clinical Misconception: Patients and nurses may
assume that if a drug binds to the same receptor, it must
produce the same effect. This misunderstanding can lead to
, unrealistic expectations of therapeutic outcomes.
Potential Medication Safety Risk: If the patient expects the
partial agonist to have the same effect as the full agonist, they
may become non-adherent when they don't experience the
same level of symptom relief, leading to worsening heart
failure.
Appropriate Nursing Consideration: Educate patients that
although partial agonists bind to the same receptors, their
effects are more moderate and often safer for chronic
conditions.
C. Why It Is Incorrect: Potency (the dose required to produce a
given effect) is a separate concept from maximal efficacy. A
partial agonist can be more potent than a full agonist (lower
ED50) while still having lower maximal efficacy. Potency does
not predict efficacy.
Common Clinical Misconception: The terms "potency" and
"efficacy" are often confused in clinical practice. A more potent
drug is not necessarily more effective.
Potential Medication Safety Risk: Misunderstanding potency
could lead to incorrect dosing decisions. The nurse might
incorrectly assume a more potent partial agonist requires
higher doses to achieve effectiveness.
Appropriate Nursing Consideration: Use the dose-response
curve to teach patients about the difference between how
