TEST BANK BASED ON:
Calculating Drug Dosages
A Patient-Safe Approach to Nursing and Math
3rd Edition
• Author(s)Sandra Luz Martinez de Castillo;
Maryanne Werner-McCullough
Chapter Reference: Chapter 1 — Safety in Medication
Administration
Stem: A nurse receives a handwritten order: Digoxin 0.125 mg
PO daily. Before administration, which single action best follows
the medication-safety principles in Chapter 1?
A. Give the medication as written because the dose is
commonly used.
B. Verify the patient's current heart rate and the most recent
electrolyte values before administering.
C. Call pharmacy to change the dose to a tablet strength that is
easier to give.
D. Administer and document immediately to avoid delay.
Correct Answer: B
Rationales:
, • Correct (B): Digoxin requires assessment (heart rate) and
often electrolyte checks (K⁺, Mg²⁺) prior to administration
because bradycardia or abnormal electrolytes increase
toxicity risk. This follows the safety principle of right
assessment before giving certain meds. (Conceptual — no
arithmetic.)
• A: Incorrect — “commonly used” is not sufficient; patient
assessment is required for digoxin safety.
• C: Incorrect — Changing dose without prescriber
order/pharmacy collaboration can introduce error; tablet
selection requires prescriber/pharmacy confirmation.
• D: Incorrect — Immediate administration without
assessment could harm the patient if contraindications
exist.
Teaching Point: Always perform required assessments before
administering high-risk medications.
2.
Chapter Reference: Chapter 1 — Safety in Medication
Administration
Stem: Which of the following is the best example of a “Do Not
Use” abbreviation error described in Chapter 1 and national
guidance?
,A. Writing “1 mg” instead of “1.0 mg.”
B. Writing “.5 mg” instead of “0.5 mg.”
C. Writing “0.5 mg” instead of “.5 mg.”
D. Writing “one half mg” instead of “0.5 mg.”
Correct Answer: B
Rationales:
• Correct (B): Omitting a leading zero (writing “.5 mg”) is
error-prone—decimal point can be missed and interpreted
as “5 mg.” ISMP and Joint Commission advise using leading
zeros (0.5). ECRI and ISMP
• A: Incorrect — Writing “1 mg” (without trailing zero) is
correct practice; 1.0 mg would be the error (trailing zero).
• C: Incorrect — “0.5 mg” is the correct format; it’s not an
example of an error.
• D: Incorrect — Writing “one half mg” is awkward but not a
standard “Do Not Use” error; use numeric format with
leading zero.
Teaching Point: Always use a leading zero for doses <1 (e.g., 0.5
mg).
3.
Chapter Reference: Chapter 1 — Safety in Medication
Administration
, Stem: A prescriber writes: Morphine 10 mg IV q4h PRN for
severe pain. Which action best reflects safe practice from
Chapter 1 when preparing to administer?
A. Administer morphine and document effectiveness later.
B. Verify the order and check facility policy if morphine requires
an independent double-check.
C. Substitute hydromorphone if morphine is unavailable
without contacting provider.
D. Split the dose if the patient looks frail to reduce risk.
Correct Answer: B
Rationales:
• Correct (B): Morphine (an opioid) is often a high-alert
medication requiring verification; Chapter 1 emphasizes
verifying orders and following independent double-check
policies when indicated. ISMP recommends selective
independent double checks for high-risk meds. ECRI and
ISMP+1
• A: Incorrect — Administering without verifying
policies/requirements is unsafe.
• C: Incorrect — Substitutions require prescriber/pharmacy
approval; unauthorized substitutions cause errors.
• D: Incorrect — Arbitrary dose splitting without prescriber
order is unsafe.
Calculating Drug Dosages
A Patient-Safe Approach to Nursing and Math
3rd Edition
• Author(s)Sandra Luz Martinez de Castillo;
Maryanne Werner-McCullough
Chapter Reference: Chapter 1 — Safety in Medication
Administration
Stem: A nurse receives a handwritten order: Digoxin 0.125 mg
PO daily. Before administration, which single action best follows
the medication-safety principles in Chapter 1?
A. Give the medication as written because the dose is
commonly used.
B. Verify the patient's current heart rate and the most recent
electrolyte values before administering.
C. Call pharmacy to change the dose to a tablet strength that is
easier to give.
D. Administer and document immediately to avoid delay.
Correct Answer: B
Rationales:
, • Correct (B): Digoxin requires assessment (heart rate) and
often electrolyte checks (K⁺, Mg²⁺) prior to administration
because bradycardia or abnormal electrolytes increase
toxicity risk. This follows the safety principle of right
assessment before giving certain meds. (Conceptual — no
arithmetic.)
• A: Incorrect — “commonly used” is not sufficient; patient
assessment is required for digoxin safety.
• C: Incorrect — Changing dose without prescriber
order/pharmacy collaboration can introduce error; tablet
selection requires prescriber/pharmacy confirmation.
• D: Incorrect — Immediate administration without
assessment could harm the patient if contraindications
exist.
Teaching Point: Always perform required assessments before
administering high-risk medications.
2.
Chapter Reference: Chapter 1 — Safety in Medication
Administration
Stem: Which of the following is the best example of a “Do Not
Use” abbreviation error described in Chapter 1 and national
guidance?
,A. Writing “1 mg” instead of “1.0 mg.”
B. Writing “.5 mg” instead of “0.5 mg.”
C. Writing “0.5 mg” instead of “.5 mg.”
D. Writing “one half mg” instead of “0.5 mg.”
Correct Answer: B
Rationales:
• Correct (B): Omitting a leading zero (writing “.5 mg”) is
error-prone—decimal point can be missed and interpreted
as “5 mg.” ISMP and Joint Commission advise using leading
zeros (0.5). ECRI and ISMP
• A: Incorrect — Writing “1 mg” (without trailing zero) is
correct practice; 1.0 mg would be the error (trailing zero).
• C: Incorrect — “0.5 mg” is the correct format; it’s not an
example of an error.
• D: Incorrect — Writing “one half mg” is awkward but not a
standard “Do Not Use” error; use numeric format with
leading zero.
Teaching Point: Always use a leading zero for doses <1 (e.g., 0.5
mg).
3.
Chapter Reference: Chapter 1 — Safety in Medication
Administration
, Stem: A prescriber writes: Morphine 10 mg IV q4h PRN for
severe pain. Which action best reflects safe practice from
Chapter 1 when preparing to administer?
A. Administer morphine and document effectiveness later.
B. Verify the order and check facility policy if morphine requires
an independent double-check.
C. Substitute hydromorphone if morphine is unavailable
without contacting provider.
D. Split the dose if the patient looks frail to reduce risk.
Correct Answer: B
Rationales:
• Correct (B): Morphine (an opioid) is often a high-alert
medication requiring verification; Chapter 1 emphasizes
verifying orders and following independent double-check
policies when indicated. ISMP recommends selective
independent double checks for high-risk meds. ECRI and
ISMP+1
• A: Incorrect — Administering without verifying
policies/requirements is unsafe.
• C: Incorrect — Substitutions require prescriber/pharmacy
approval; unauthorized substitutions cause errors.
• D: Incorrect — Arbitrary dose splitting without prescriber
order is unsafe.
