Nursing Pharmacology Test Bank
Chapter 5: Dosage Calculations
Based on: Focus on Nursing Pharmacology
8th Edition by Amy M. Karch
✔ Verified NCLEX-Style Questions
✔ Detailed Rationales for Every Answer
✔ Covers Core Pharmacology Concepts
✔ Ideal for Nursing Students, ATI, HESI, and NCLEX Prep
Disclaimer: This document is intended for educational purposes only. It is an original, student-created study aid based
on the listed textbook. This material is not affiliated with, endorsed by, or sourced from the publisher or author. Use
this resource responsibly and in accordance with your institution’s academic policies.
,NCLEX Pharmacology Test Bank – Chapter 5 Dosage Calculations – 50 Questions + Rationales +
Cheat Sheet – Karch Focus on Nursing Pharmacology 8th Edition
1. A provider orders ampicillin 500 mg PO every 6 hours. The pharmacy sends 250 mg tablets.
How many tablets will the nurse administer per dose?
A. ½ tablet
B. 1 tablet
C. 2 tablets
D. 3 tablets
Correct Answer: C. 2 tablets
Rationale: 500 mg ÷ 250 mg = 2 tablets per dose
2. A client is prescribed 1,000 mL of IV fluid to infuse over 8 hours. The drop factor is 15
gtt/mL. What is the correct drip rate in gtt/min?
A. 15 gtt/min
B. 21 gtt/min
C. 31 gtt/min
D. 39 gtt/min
Correct Answer: C. 31 gtt/min
Rationale:
1,000 mL ÷ 8 hr = 125 mL/hr
125 mL/hr × 15 gtt/mL ÷ 60 = 31.25 ≈ 31 gtt/min
3. A child weighs 18 kg. The safe dose range for a drug is 10–20 mg/kg/day divided into 2
doses. What is the maximum amount per dose?
A. 90 mg
B. 180 mg
C. 200 mg
D. 360 mg
Correct Answer: B. 180 mg
Rationale:
20 mg × 18 kg = 360 mg/day ÷ 2 doses = 180 mg per dose
2
, NCLEX Pharmacology Test Bank – Chapter 5 Dosage Calculations – 50 Questions + Rationales +
Cheat Sheet – Karch Focus on Nursing Pharmacology 8th Edition
4. A nurse is to give 2 mg/kg of a medication to a child who weighs 22 lb. What is the correct
dose in mg? (Round to nearest tenth)
A. 10.0 mg
B. 12.0 mg
C. 20.0 mg
D. 22.0 mg
Correct Answer: B. 20.0 mg
Rationale:
22 lb ÷ 2.2 = 10 kg × 2 mg = 20 mg
5. A patient is prescribed heparin 5,000 units subcutaneously every 8 hours. The vial reads
10,000 units/mL. How many mL will the nurse administer?
A. 0.25 mL
B. 0.5 mL
C. 1 mL
D. 2 mL
Correct Answer: B. 0.5 mL
Rationale:
5,000 units ÷ 10,000 units/mL = 0.5 mL
6. A provider orders dopamine 5 mcg/kg/min IV for a 70 kg patient. The bag contains 400 mg
in 250 mL. What rate in mL/hr should be set?
A. 13.1 mL/hr
B. 22.5 mL/hr
C. 32.8 mL/hr
D. 52.5 mL/hr
Correct Answer: C. 32.8 mL/hr
Rationale:
Total mcg/min = 5 × 70 = 350 mcg/min
Convert to mg/hr: 350 mcg/min × 60 = 21,000 mcg/hr = 21 mg/hr
400 mg : 250 mL = 21 mg : X → X = 32.8 mL/hr
3
Chapter 5: Dosage Calculations
Based on: Focus on Nursing Pharmacology
8th Edition by Amy M. Karch
✔ Verified NCLEX-Style Questions
✔ Detailed Rationales for Every Answer
✔ Covers Core Pharmacology Concepts
✔ Ideal for Nursing Students, ATI, HESI, and NCLEX Prep
Disclaimer: This document is intended for educational purposes only. It is an original, student-created study aid based
on the listed textbook. This material is not affiliated with, endorsed by, or sourced from the publisher or author. Use
this resource responsibly and in accordance with your institution’s academic policies.
,NCLEX Pharmacology Test Bank – Chapter 5 Dosage Calculations – 50 Questions + Rationales +
Cheat Sheet – Karch Focus on Nursing Pharmacology 8th Edition
1. A provider orders ampicillin 500 mg PO every 6 hours. The pharmacy sends 250 mg tablets.
How many tablets will the nurse administer per dose?
A. ½ tablet
B. 1 tablet
C. 2 tablets
D. 3 tablets
Correct Answer: C. 2 tablets
Rationale: 500 mg ÷ 250 mg = 2 tablets per dose
2. A client is prescribed 1,000 mL of IV fluid to infuse over 8 hours. The drop factor is 15
gtt/mL. What is the correct drip rate in gtt/min?
A. 15 gtt/min
B. 21 gtt/min
C. 31 gtt/min
D. 39 gtt/min
Correct Answer: C. 31 gtt/min
Rationale:
1,000 mL ÷ 8 hr = 125 mL/hr
125 mL/hr × 15 gtt/mL ÷ 60 = 31.25 ≈ 31 gtt/min
3. A child weighs 18 kg. The safe dose range for a drug is 10–20 mg/kg/day divided into 2
doses. What is the maximum amount per dose?
A. 90 mg
B. 180 mg
C. 200 mg
D. 360 mg
Correct Answer: B. 180 mg
Rationale:
20 mg × 18 kg = 360 mg/day ÷ 2 doses = 180 mg per dose
2
, NCLEX Pharmacology Test Bank – Chapter 5 Dosage Calculations – 50 Questions + Rationales +
Cheat Sheet – Karch Focus on Nursing Pharmacology 8th Edition
4. A nurse is to give 2 mg/kg of a medication to a child who weighs 22 lb. What is the correct
dose in mg? (Round to nearest tenth)
A. 10.0 mg
B. 12.0 mg
C. 20.0 mg
D. 22.0 mg
Correct Answer: B. 20.0 mg
Rationale:
22 lb ÷ 2.2 = 10 kg × 2 mg = 20 mg
5. A patient is prescribed heparin 5,000 units subcutaneously every 8 hours. The vial reads
10,000 units/mL. How many mL will the nurse administer?
A. 0.25 mL
B. 0.5 mL
C. 1 mL
D. 2 mL
Correct Answer: B. 0.5 mL
Rationale:
5,000 units ÷ 10,000 units/mL = 0.5 mL
6. A provider orders dopamine 5 mcg/kg/min IV for a 70 kg patient. The bag contains 400 mg
in 250 mL. What rate in mL/hr should be set?
A. 13.1 mL/hr
B. 22.5 mL/hr
C. 32.8 mL/hr
D. 52.5 mL/hr
Correct Answer: C. 32.8 mL/hr
Rationale:
Total mcg/min = 5 × 70 = 350 mcg/min
Convert to mg/hr: 350 mcg/min × 60 = 21,000 mcg/hr = 21 mg/hr
400 mg : 250 mL = 21 mg : X → X = 32.8 mL/hr
3
