Calculating Drug Dosages
A Patient-Safe Approach to Nursing and Math
Sandra Luz Martinez de Castillo, Maryanne Werner-McCullough
3rd Edition
,Table of Contents
Unit One. Safety in Medication Administration
Chapter 1. Safety in Medication Administration
Chapter 2. The Drug Label
Unit Two. Systems of Measurement
Chapter 3. The Metric System
Chapter 4. The Household System
Unit Three. Methods of Calculation
Chapter 5. Linear Ratio and Proportion
Chapter 6. Fractional Ratio and Proportion
Chapter 7. Dimensional Analysis
Chapter 8. Formula Method
Unit Four. Administration of Medications
Chapter 9. Calculating Oral Medication Doses
Chapter 10. Syringes and Needles
Chapter 11. Calculating Parenteral Medication Dosages
Chapter 12. Preparing Powdered Parenteral Medications
Chapter 13. Administration of Insulin
Unit Five. IV Therapy and Administration of Intravenous Medications
Chapter 14. Intravenous Infusion and Infusion Rates
Chapter 15. Calculating Infusion and Completion Time
Chapter 16. Administering IV Push Medications
Unit Six. Titration and Verifying Safe Dose
Chapter 17. Titration of Intravenous Medications
Chapter 18. Verifying Safe Dose
Unit Seven. Intake and Output
Chapter 19. Calculating Intake and Output
Chapter 20. Parenteral Intake
Unit Eight. Dosages for Pediatric and Older Adult Populations
Chapter 21. Considerations for the Pediatric Population
Chapter 22. Considerations for the Older Adult Population
,Test Bank - Calculating Drug Dosages: A Patient-Safe Approach to Nursing and Math 3rd Edition (Castillo, 2025)
Chapter 1: Safety in Medication Administration
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Castillo: Calculating Drug Dosages: A Patient-Safe Approach to Nursing and Math 3rd Edition
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MULTIPLE CHOICE DC
1. The following medication order is in the patient’s medication administration record (MAR):
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methylPREDnisolone 40 mg PO daily at 0900. DC DC DC DC DC DC
After DC reading the order, the nurse correctly determines:
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A “PO” is an inappropriate abbreviation.
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B the medication order is written correctly.
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C 40 mg should be written as 40mg.
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D tall man lettering indicates that the drug is a narco
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tic.
ANSWER: B DC
Feedback
The medication order has all the required components (drug name, dose, rout
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e, andfrequency of administration) for a drug order. “PO” is an appropriate a
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bbreviation;40 mg is written correctly with a space between the dose and the
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unit of measurement. Tall man lettering is used to distinguish the drug from
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another drug
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with a similar name.
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2. Which DC of the following accurately describes the “Boxed Warning” found on a drug label?
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A It is primarily is used to identify the safe dose for the patient.
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B It is commonly found on all drug labels.
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C It identifies serious potential risks and side effects related to drug u
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se.
D It protects the patient by providing information to decrease side effe
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cts.
ANSWER: C DC
Feedback
A drug label with a boxed warning provides information to healthcare profess
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ionalsand patients regarding the serious risks and side effects related to the dr
C
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ug. The Boxed Warning is not the primary source for identifying the patient’s
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drug dosage.
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The warning is found on specific prescription medications and does not p
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rovideinformation to reduce or decrease side effects.
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3
,Test Bank - Calculating Drug Dosages: A Patient-Safe Approach to Nursing and Math 3rd Edition (Castillo, 2025)
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3. When practicing safety in the administration of medication, for which of the fol
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lowingmedication orders should a nurse seek clarification before the administrati
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on of the medication?
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4
,Test Bank - Calculating Drug Dosages: A Patient-Safe Approach to Nursing and Math 3rd Edition (Castillo, 2025)
A Regular insulin 5 u subcut now.
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B Enoxaparin 80 mg subcut every 12 hours.
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C Benadryl 50 mg PO PRN every 6 hr for itchi
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ng.
D Ondansetron 4 mg IVP stat. DC DC DC DC
ANSWER: A DC
Feedback
The “u” should never be used in a medication order; rather, for safety, th
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e word“units” should be spelled out. The other answer options contain th
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e required
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components needed to safely carry out the medication order.
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4. A nurse is reviewing a drug label with a drug name written with tall man lettering.
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Which statements shows the nurse has a correct understanding of tall man lettering o
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n a drug label?
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A “The tall man lettering means this is a high alert drug.”
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B “The tall man lettering helps me distinguish this drug with other drugs tha
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t
have similar names.” DC DC
C “The tall man lettering means that this drug must have a Boxed Warning.
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”
D “The tall man lettering helps me quickly identify that this drug is an injec
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table
drug.”
ANSWER: B DC
Feedback
Tall man lettering highlights a portion of the drug name to help distinguis
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h from imilar drug names. It is not used to identify high alert drugs, highl
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ight a boxed DC DC
warning, or identify injectable drugs.
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5. The following medication orders are found in the patient’s MAR:
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Metformin HCl 500 mg PO daily at 0900. Hydrochloroth
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iazide 25 mg PO every 12 hr at 0900 and 2100.Digoxin .
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D DC
25 mg PO daily at 0900.
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In reading the medication orders for the 0700–
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1500 shift, the nurse determines that which ofthe following is the priority nursing int
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D DC DC DC DC DC DC
ervention?
5
,Test Bank - Calculating Drug Dosages: A Patient-Safe Approach to Nursing and Math 3rd Edition (Castillo, 2025)
A Clarify the metformin HCl order.
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B Clarify the hydrochlorothiazide order.
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C Clarify the digoxin order.
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D Prepare to administer the 0900 medications
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.
ANSWER: C DC
6
,Test Bank - Calculating Drug Dosages: A Patient-Safe Approach to Nursing and Math 3rd Edition (Castillo, 2025)
Feedback
The digoxin medication order is lacking a zero before the decimal fraction (.
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25). Safe practice recommends using a zero before a decimal point when the
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dose is lessthan one. The metformin HCl and the hydrochlorothiazide orders
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are written
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correctly. The order should be clarified before preparing the 0900 medications.
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6. In the administration of medications, when should the nurse document the administrat
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ion ofmedications?
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D
A 30 minutes before administering to the patient.
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B Immediately before administering to the patient DC DC DC DC DC
.
C At the end of the shift. DC DC DC DC DC
D Immediately after administering to the patient. DC DC DC DC DC
ANSWER: D DC
Feedback
The last “Right of Medication Administration” is the documentation of medicati
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ons.The documentation is done immediately after administering the medications
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to the
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patient.
7. The following medication is ordered for the patient:
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Calcitriol Oral Solution 2 µg PO Daily
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After DC reading the order, what is the initial action needed by the nurse?
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A Clarify the written medication dose of 2 µg.
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B Look up the dose in a drug reference book.
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C Transcribe the medication order onto the MA
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R.
D Ask the patient the daily dose taken at home.
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ANSWER: A DC
Feedback
The initial action is for the nurse to clarify the drug dose because it is writ
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ten withthe error-
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D DC
prone letter/symbol “µ.” To avoid medication errors, it is recommended
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that the “µ” not be used in medication orders. Instead the abbreviation “mc
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g” is tobe used for microgram.
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D DC DC DC
7
, Test Bank - Calculating Drug Dosages: A Patient-Safe Approach to Nursing and Math 3rd Edition (Castillo, 2025)
8. Recommendations by the Institute of Medicine for reducing medication errors help en
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hance afe nursing practice by:
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8