LEHNE'S PHARMACOTHERAPEUTICS FOR ADVANCED
PRACTICE NURSES & PHYSICIAN ASSISTANTS, 3RD
EDITION (PDF) | 2026 EXAM QUESTIONS AND ANSWERS +
RATIONALES | STUDY GUIDE | 100% CORRECT
1. An APRN in a state with restricted prescriptive authority is required to have which of the
following in place to prescribe controlled substances?
A) A collaborative practice agreement with a physician
B) A DEA registration number only
C) A supervisory relationship with a pharmacist
D) A written referral from a specialist for each prescription
Correct Answer: A) A collaborative practice agreement with a physician
Rationale: In states with restricted prescriptive authority, APRNs must have a collaborative
practice agreement or supervisory relationship with a physician to prescribe, particularly for
controlled substances. DEA registration is required in all states but does not alone confer
prescriptive authority. Pharmacists do not supervise prescribing, and specialist referrals are not
required for each prescription .
2. A patient with a known allergy to penicillin is prescribed a cephalosporin. The APRN should:
A) Administer the cephalosporin without concern as cross-reactivity is a myth
B) Use a penicillin skin test before administering the cephalosporin
C) Prescribe the cephalosporin but observe the patient closely for 30 minutes after the first dose
D) Avoid the cephalosporin unless absolutely necessary due to potential cross-reactivity
Correct Answer: D) Avoid the cephalosporin unless absolutely necessary due to potential cross-
reactivity
Rationale: There is a potential cross-reactivity between penicillin and cephalosporins,
particularly first-generation cephalosporins. While the risk is lower than previously thought, it is
still recommended to avoid cephalosporins in patients with a history of severe penicillin allergy
unless absolutely necessary. Skin testing for penicillin allergy does not reliably predict
cephalosporin allergy. If a cephalosporin must be used, it should be administered in a controlled
setting with monitoring .
3. The process of rational drug selection involves all of the following EXCEPT:
A) Identifying the patient's specific diagnosis and treatment goals
B) Selecting a drug based solely on cost
C) Considering patient-specific factors such as age, renal function, and allergies
D) Monitoring for therapeutic and adverse effects after initiating therapy
Correct Answer: B) Selecting a drug based solely on cost
Rationale: Rational drug selection involves a systematic approach: accurate diagnosis, setting
therapeutic goals, considering patient-specific factors (age, organ function, allergies, concurrent
,medications), selecting the safest and most effective drug, and monitoring outcomes. Cost is a
consideration but should not be the sole factor in drug selection; efficacy and safety are
paramount .
4. A patient prescribed amoxicillin for streptococcal pharyngitis reports new onset of a flat, itchy
red rash on the chest and neck. Which action is most important?
A) Provide a different prescription
B) Discontinue the medication
C) Prescribe an antihistamine cream
D) Assess for respiratory compromise
Correct Answer: B) Discontinue the medication
Rationale: The priority action is to discontinue the medication to prevent worsening of the
patient's symptoms. A different prescription would be provided, topical antihistamine may be
administered, and the patient would be assessed for respiratory involvement, but these actions
would not be performed before discontinuing the medication .
5. A patient reports that a medication prescribed for recurrent migraine headaches is not working.
Which action should be taken first?
A) Ask the patient about the number and frequency of tablets taken
B) Assess the patient’s headache pain on a scale from 1 to 10
C) Report the patient’s complaint to the prescriber
D) Suggest biofeedback as an adjunct to drug therapy
Correct Answer: A) Ask the patient about the number and frequency of tablets taken
Rationale: When evaluating the effectiveness of a drug, it is important to determine whether the
patient is using the drug as ordered. Asking the patient to tell the nurse how many tablets are
taken and how often helps the nurse determine compliance. Assessing current pain does not yield
information about how well the medication is working unless the patient is currently taking it.
The nurse should gather as much information about compliance, symptoms, and drug
effectiveness as possible before contacting the prescriber .
6. An infant who receives a drug that does not produce CNS side effects in adults exhibits
drowsiness and sedation. The nurse understands that this is because of differences in which
physiologic system in infants and adults?
A) Blood-brain barrier
B) First-pass effect
C) Gastrointestinal absorption
D) Renal filtration
Correct Answer: A) Blood-brain barrier
Rationale: The blood-brain barrier is not fully developed at birth, making infants much more
sensitive to CNS drugs than older children and adults. CNS symptoms may include sedation and
, drowsiness. The first-pass effect and GI absorption affect metabolism and absorption of drugs,
and renal filtration affects elimination of drugs, all of which may alter drug levels .
7. A nurse is teaching a group of nursing students how the CNS adapts to psychotherapeutic
medications. Which statement by a nursing student indicates a need for further teaching?
A) "Adaptation can lead to tolerance of these drugs with prolonged use."
B) "Adaptation helps explain how physical dependence occurs."
C) "Adaptation often must occur before therapeutic effects develop."
D) "Adaptation results in an increased sensitivity to side effects over time."
Correct Answer: D) "Adaptation results in an increased sensitivity to side effects over time."
Rationale: With adaptation of the central nervous system to prolonged exposure to CNS drugs,
many adverse effects diminish and therapeutic effects remain. Adaptation helps explain how
tolerance and physical dependence occur, as the brain adapts to the presence of the drug.
Therapeutic effects can take several weeks to manifest, because they appear to work by initiating
adaptive changes in the brain .
8. Which monoamines act as neurotransmitters in the central nervous system? Select all that
apply.
A) Acetylcholine
B) Norepinephrine
C) Serotonin
D) Dopamine
E) Epinephrine
F) Histamine
Correct Answer: B, C, D, E
Rationale: The monoamines that act as neurotransmitters in the central nervous system are
norepinephrine, serotonin, dopamine, and epinephrine. Acetylcholine and histamines are not
monoamines .
9. A patient asks a nurse to explain what drug tolerance means. The nurse responds by telling the
patient that when tolerance occurs, it means the patient:
A) has developed a psychological dependence on the drug.
B) may need increased amounts of the drug over time.
C) will cause an abstinence syndrome if the drug is discontinued abruptly.
D) will have increased sensitivity to drug side effects.
Correct Answer: B) may need increased amounts of the drug over time.
Rationale: When tolerance develops, a dose increase may be needed, because a decreased
response may occur with prolonged use. Psychologic dependence involves cravings for drug
effects and does not define tolerance. Physical dependence occurs when the drug becomes
necessary for the brain to function "normally," meaning the patient should be weaned from the
PRACTICE NURSES & PHYSICIAN ASSISTANTS, 3RD
EDITION (PDF) | 2026 EXAM QUESTIONS AND ANSWERS +
RATIONALES | STUDY GUIDE | 100% CORRECT
1. An APRN in a state with restricted prescriptive authority is required to have which of the
following in place to prescribe controlled substances?
A) A collaborative practice agreement with a physician
B) A DEA registration number only
C) A supervisory relationship with a pharmacist
D) A written referral from a specialist for each prescription
Correct Answer: A) A collaborative practice agreement with a physician
Rationale: In states with restricted prescriptive authority, APRNs must have a collaborative
practice agreement or supervisory relationship with a physician to prescribe, particularly for
controlled substances. DEA registration is required in all states but does not alone confer
prescriptive authority. Pharmacists do not supervise prescribing, and specialist referrals are not
required for each prescription .
2. A patient with a known allergy to penicillin is prescribed a cephalosporin. The APRN should:
A) Administer the cephalosporin without concern as cross-reactivity is a myth
B) Use a penicillin skin test before administering the cephalosporin
C) Prescribe the cephalosporin but observe the patient closely for 30 minutes after the first dose
D) Avoid the cephalosporin unless absolutely necessary due to potential cross-reactivity
Correct Answer: D) Avoid the cephalosporin unless absolutely necessary due to potential cross-
reactivity
Rationale: There is a potential cross-reactivity between penicillin and cephalosporins,
particularly first-generation cephalosporins. While the risk is lower than previously thought, it is
still recommended to avoid cephalosporins in patients with a history of severe penicillin allergy
unless absolutely necessary. Skin testing for penicillin allergy does not reliably predict
cephalosporin allergy. If a cephalosporin must be used, it should be administered in a controlled
setting with monitoring .
3. The process of rational drug selection involves all of the following EXCEPT:
A) Identifying the patient's specific diagnosis and treatment goals
B) Selecting a drug based solely on cost
C) Considering patient-specific factors such as age, renal function, and allergies
D) Monitoring for therapeutic and adverse effects after initiating therapy
Correct Answer: B) Selecting a drug based solely on cost
Rationale: Rational drug selection involves a systematic approach: accurate diagnosis, setting
therapeutic goals, considering patient-specific factors (age, organ function, allergies, concurrent
,medications), selecting the safest and most effective drug, and monitoring outcomes. Cost is a
consideration but should not be the sole factor in drug selection; efficacy and safety are
paramount .
4. A patient prescribed amoxicillin for streptococcal pharyngitis reports new onset of a flat, itchy
red rash on the chest and neck. Which action is most important?
A) Provide a different prescription
B) Discontinue the medication
C) Prescribe an antihistamine cream
D) Assess for respiratory compromise
Correct Answer: B) Discontinue the medication
Rationale: The priority action is to discontinue the medication to prevent worsening of the
patient's symptoms. A different prescription would be provided, topical antihistamine may be
administered, and the patient would be assessed for respiratory involvement, but these actions
would not be performed before discontinuing the medication .
5. A patient reports that a medication prescribed for recurrent migraine headaches is not working.
Which action should be taken first?
A) Ask the patient about the number and frequency of tablets taken
B) Assess the patient’s headache pain on a scale from 1 to 10
C) Report the patient’s complaint to the prescriber
D) Suggest biofeedback as an adjunct to drug therapy
Correct Answer: A) Ask the patient about the number and frequency of tablets taken
Rationale: When evaluating the effectiveness of a drug, it is important to determine whether the
patient is using the drug as ordered. Asking the patient to tell the nurse how many tablets are
taken and how often helps the nurse determine compliance. Assessing current pain does not yield
information about how well the medication is working unless the patient is currently taking it.
The nurse should gather as much information about compliance, symptoms, and drug
effectiveness as possible before contacting the prescriber .
6. An infant who receives a drug that does not produce CNS side effects in adults exhibits
drowsiness and sedation. The nurse understands that this is because of differences in which
physiologic system in infants and adults?
A) Blood-brain barrier
B) First-pass effect
C) Gastrointestinal absorption
D) Renal filtration
Correct Answer: A) Blood-brain barrier
Rationale: The blood-brain barrier is not fully developed at birth, making infants much more
sensitive to CNS drugs than older children and adults. CNS symptoms may include sedation and
, drowsiness. The first-pass effect and GI absorption affect metabolism and absorption of drugs,
and renal filtration affects elimination of drugs, all of which may alter drug levels .
7. A nurse is teaching a group of nursing students how the CNS adapts to psychotherapeutic
medications. Which statement by a nursing student indicates a need for further teaching?
A) "Adaptation can lead to tolerance of these drugs with prolonged use."
B) "Adaptation helps explain how physical dependence occurs."
C) "Adaptation often must occur before therapeutic effects develop."
D) "Adaptation results in an increased sensitivity to side effects over time."
Correct Answer: D) "Adaptation results in an increased sensitivity to side effects over time."
Rationale: With adaptation of the central nervous system to prolonged exposure to CNS drugs,
many adverse effects diminish and therapeutic effects remain. Adaptation helps explain how
tolerance and physical dependence occur, as the brain adapts to the presence of the drug.
Therapeutic effects can take several weeks to manifest, because they appear to work by initiating
adaptive changes in the brain .
8. Which monoamines act as neurotransmitters in the central nervous system? Select all that
apply.
A) Acetylcholine
B) Norepinephrine
C) Serotonin
D) Dopamine
E) Epinephrine
F) Histamine
Correct Answer: B, C, D, E
Rationale: The monoamines that act as neurotransmitters in the central nervous system are
norepinephrine, serotonin, dopamine, and epinephrine. Acetylcholine and histamines are not
monoamines .
9. A patient asks a nurse to explain what drug tolerance means. The nurse responds by telling the
patient that when tolerance occurs, it means the patient:
A) has developed a psychological dependence on the drug.
B) may need increased amounts of the drug over time.
C) will cause an abstinence syndrome if the drug is discontinued abruptly.
D) will have increased sensitivity to drug side effects.
Correct Answer: B) may need increased amounts of the drug over time.
Rationale: When tolerance develops, a dose increase may be needed, because a decreased
response may occur with prolonged use. Psychologic dependence involves cravings for drug
effects and does not define tolerance. Physical dependence occurs when the drug becomes
necessary for the brain to function "normally," meaning the patient should be weaned from the
