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
1. Chapter Reference
Chapter 1. Safety in Medication Administration — Section:
Medication Orders & the "Five Rights" — Title: Verifying a
Medication Order
Stem
A nurse receives a verbal order: “Give digoxin 0.125 mg now.” Before
administering, which action best ensures safe medication
administration?
,A. Administer the dose immediately since the order is specific.
B. Ask the prescriber to confirm the patient’s most recent heart rate and
intent of the order.
C. Call pharmacy to check whether 0.125 mg is a stocked strength.
D. Ask another nurse to document the verbal order while you give the
medication.
Correct Answer
B
Rationales
• Correct (B): The nurse must verify appropriateness of digoxin by
confirming the patient’s heart rate and clarifying intent to prevent
harm; this is a critical safety step before administration.
• A (incorrect): Administering immediately without assessing heart
rate ignores a key safety check (digoxin affects heart rate).
• C (incorrect): Pharmacy checking stock does not replace clinical
verification of suitability for this patient.
• D (incorrect): Having someone document while administering still
bypasses necessary patient-specific verification.
,Teaching Point
Always verify patient-specific parameters (e.g., heart rate) before giving
high-risk meds.
2. Chapter Reference
Chapter 1. Safety in Medication Administration — Section: Unit
Conversions — Title: Volume from Strength
Stem
Order: Ampicillin 250 mg PO. Available: 125 mg per 5 mL
suspension. How many mL should the nurse administer?
A. 5 mL
B. 7.5 mL
C. 10 mL
D. 15 mL
Correct Answer
C
Rationales
• Correct (C): Use
DesiredHave×Volume=250 mg125 mg×5 mL=2×5 mL=10 mL.\fra
, c{Desired}{Have} \times Volume = \frac{250\text{ mg}}{125\text{
mg}} \times 5\text{ mL} = 2 \times 5\text{ mL} = 10\text{
mL}.HaveDesired×Volume=125 mg250 mg
×5 mL=2×5 mL=10 mL.
• A (incorrect): 5 mL would provide only 125 mg (under-dose).
• B (incorrect): 7.5 mL reflects a mistaken computation (possibly
5+2.55 + 2.55+2.5 or wrong division).
• D (incorrect): 15 mL would deliver 375 mg (overdose) — likely
from multiplying by 3 instead of 2.
Teaching Point
Use the DH×V\frac{D}{H}\times VHD×V formula to calculate correct
liquid volumes.
3. Chapter Reference
Chapter 1. Safety in Medication Administration — Section:
Pediatric Safety — Title: Weight-Based Dose to Volume
Stem
A child weighing 18 kg is prescribed 15 mg/kg PO once. Available: 100
mg per 5 mL. What volume (mL) should the nurse give?
Calculating Drug Dosages
A Patient-Safe Approach to Nursing and Math
3rd Edition
• Author(s)Sandra Luz Martinez de Castillo;
Maryanne Werner-McCullough
1. Chapter Reference
Chapter 1. Safety in Medication Administration — Section:
Medication Orders & the "Five Rights" — Title: Verifying a
Medication Order
Stem
A nurse receives a verbal order: “Give digoxin 0.125 mg now.” Before
administering, which action best ensures safe medication
administration?
,A. Administer the dose immediately since the order is specific.
B. Ask the prescriber to confirm the patient’s most recent heart rate and
intent of the order.
C. Call pharmacy to check whether 0.125 mg is a stocked strength.
D. Ask another nurse to document the verbal order while you give the
medication.
Correct Answer
B
Rationales
• Correct (B): The nurse must verify appropriateness of digoxin by
confirming the patient’s heart rate and clarifying intent to prevent
harm; this is a critical safety step before administration.
• A (incorrect): Administering immediately without assessing heart
rate ignores a key safety check (digoxin affects heart rate).
• C (incorrect): Pharmacy checking stock does not replace clinical
verification of suitability for this patient.
• D (incorrect): Having someone document while administering still
bypasses necessary patient-specific verification.
,Teaching Point
Always verify patient-specific parameters (e.g., heart rate) before giving
high-risk meds.
2. Chapter Reference
Chapter 1. Safety in Medication Administration — Section: Unit
Conversions — Title: Volume from Strength
Stem
Order: Ampicillin 250 mg PO. Available: 125 mg per 5 mL
suspension. How many mL should the nurse administer?
A. 5 mL
B. 7.5 mL
C. 10 mL
D. 15 mL
Correct Answer
C
Rationales
• Correct (C): Use
DesiredHave×Volume=250 mg125 mg×5 mL=2×5 mL=10 mL.\fra
, c{Desired}{Have} \times Volume = \frac{250\text{ mg}}{125\text{
mg}} \times 5\text{ mL} = 2 \times 5\text{ mL} = 10\text{
mL}.HaveDesired×Volume=125 mg250 mg
×5 mL=2×5 mL=10 mL.
• A (incorrect): 5 mL would provide only 125 mg (under-dose).
• B (incorrect): 7.5 mL reflects a mistaken computation (possibly
5+2.55 + 2.55+2.5 or wrong division).
• D (incorrect): 15 mL would deliver 375 mg (overdose) — likely
from multiplying by 3 instead of 2.
Teaching Point
Use the DH×V\frac{D}{H}\times VHD×V formula to calculate correct
liquid volumes.
3. Chapter Reference
Chapter 1. Safety in Medication Administration — Section:
Pediatric Safety — Title: Weight-Based Dose to Volume
Stem
A child weighing 18 kg is prescribed 15 mg/kg PO once. Available: 100
mg per 5 mL. What volume (mL) should the nurse give?
