Dosage Calculation RN Fundamentals Online
Practice Assessment 3.0
Question
1. A nurse is preparing to administer codeine 20 mg PO every 6 hr PRN pain. Available is
codeine oral solution 10 mg/ 5 mL. How many mL should the nurse administer per dose?
(Round to the nearest whole number. Use a leading zero if it applies. Do not use atrailing zero.)
Answer: 10 mL
Follow these steps for the Ratio and Proportion method of calculation:
Step 1: What is the unit of measurement the nurse should calculate? mL
Step 2: What is the dose the nurse should administer? Dose to administer = Desired 20 mg
Step 3: What is the dose available? Dose available = Have 10 mg
Step 4: Should the nurse convert the units of measurement? No
Step 5: What is the quantity of the dose available? 5 mL
Step 6: Set up an equation and solve for X. Have/Quantity = Desired/X
10 mg/ 5 mL = 20 mg/ X mL
X mL = 10 mL
Step 7: Round if necessary.
,Step 8: Determine whether the amount to administer makes sense. If there are 10 mg/5 mL and
the prescription reads 20 mg, it makes sense to administer 10 mL. The nurse should administer
codeine oral solution 10 mL PO every 6 hr PRN pain.
Question
2. A nurse is preparing to administer eszopiclone 2,000 mcg PO to a client. How many mg
should the nurse administer? (Round to the nearest whole number. Use a leading zero if it
applies. Do not use a trailing zero.)
Answer: 2 mg
Follow these steps for the Ratio and Proportion method of calculation:
Step 1: What is the unit of measurement the nurse should calculate? mg
Step 2: What is the dose the nurse should administer? Dose to administer = Desired 2,000 mcg
Step 3: What is the dose available? Dose available = Have 1 mg
Step 4: Should the nurse convert the units of measurement? Yes (mcg does not equal mg)
1,000 mcg/1 mg = 2,000 mcg/X mg
X mg = 2 mg
Step 5: Round if necessary.
,Step 6: Determine whether the amount to administer makes sense. If the prescription reads 2,000
mcg and 1,000 mcg equals 1 mg, it makes sense to administer 2 mg. The nurse should administer
eszopiclone 2 mg PO.
Question
3. A nurse is preparing to administer tobramycin 4 mg/kg/day IM divided in three equal doses to
a patient who weighs 60 kg. Available is tobramycin 40 mg/mL. How many mL should the nurse
administer per dose? (Round to the nearest whole number. Use a leading zero if it applies. Do not
use a trailing zero.)
Answer: 2 mL
Follow these steps for the Ratio and Proportion method of calculation:
Step 1: What is the unit of measurement the nurse should calculate? mg
Step 2: Set up an equation and solve for X. X = Dose per kg × Client's weight in kg
X mg = 4 mg/kg × 60 kg
X mg = 240 mg
The dose is divided into three equal doses; therefore, divide X by 3. 240 mg = 80 mg3
Step 3: What is the unit of measurement the nurse should calculate? mL
Step 4: What is the dose the nurse should administer? Dose to administer = Desired 80 mg
Step 5: What is the dose available? Dose available = Have 40 mg
, Step 6: Should the nurse convert the units of measurement? No
Step 7: What is the quantity of the dose available? 1 mL
Step 8: Set up an equation and solve for X. Have/Quantity = Desired/X
40 mg/1 mL = 80 mg/X mL
X mL = 2 mL
Step 9: Round if necessary.
Step 10: Determine whether the amount to administer makes sense. If there are 40 mg/mL and
the prescription reads 4 mg/kg/day divided in three equal doses, it makes sense to administer 2
mL. The nurse should administer tobramycin 2 mL IM per dose.
Question
4. A nurse is preparing to administer meperidine 75 mg IM stat. Available is meperidine injection
100 mg/mL. How many mL should the nurse administer? (Round answer to nearest hundredth.
Use a leading zero if it applies. Do not use a trailing zero.)
Answer: 0.75 mL
Follow these steps for the Ratio and Proportion method of calculation:
Step 1: What is the unit of measurement the nurse should calculate? mL
Step 2: What is the dose the nurse should administer?
Dose to administer = Desired 75 mg
Practice Assessment 3.0
Question
1. A nurse is preparing to administer codeine 20 mg PO every 6 hr PRN pain. Available is
codeine oral solution 10 mg/ 5 mL. How many mL should the nurse administer per dose?
(Round to the nearest whole number. Use a leading zero if it applies. Do not use atrailing zero.)
Answer: 10 mL
Follow these steps for the Ratio and Proportion method of calculation:
Step 1: What is the unit of measurement the nurse should calculate? mL
Step 2: What is the dose the nurse should administer? Dose to administer = Desired 20 mg
Step 3: What is the dose available? Dose available = Have 10 mg
Step 4: Should the nurse convert the units of measurement? No
Step 5: What is the quantity of the dose available? 5 mL
Step 6: Set up an equation and solve for X. Have/Quantity = Desired/X
10 mg/ 5 mL = 20 mg/ X mL
X mL = 10 mL
Step 7: Round if necessary.
,Step 8: Determine whether the amount to administer makes sense. If there are 10 mg/5 mL and
the prescription reads 20 mg, it makes sense to administer 10 mL. The nurse should administer
codeine oral solution 10 mL PO every 6 hr PRN pain.
Question
2. A nurse is preparing to administer eszopiclone 2,000 mcg PO to a client. How many mg
should the nurse administer? (Round to the nearest whole number. Use a leading zero if it
applies. Do not use a trailing zero.)
Answer: 2 mg
Follow these steps for the Ratio and Proportion method of calculation:
Step 1: What is the unit of measurement the nurse should calculate? mg
Step 2: What is the dose the nurse should administer? Dose to administer = Desired 2,000 mcg
Step 3: What is the dose available? Dose available = Have 1 mg
Step 4: Should the nurse convert the units of measurement? Yes (mcg does not equal mg)
1,000 mcg/1 mg = 2,000 mcg/X mg
X mg = 2 mg
Step 5: Round if necessary.
,Step 6: Determine whether the amount to administer makes sense. If the prescription reads 2,000
mcg and 1,000 mcg equals 1 mg, it makes sense to administer 2 mg. The nurse should administer
eszopiclone 2 mg PO.
Question
3. A nurse is preparing to administer tobramycin 4 mg/kg/day IM divided in three equal doses to
a patient who weighs 60 kg. Available is tobramycin 40 mg/mL. How many mL should the nurse
administer per dose? (Round to the nearest whole number. Use a leading zero if it applies. Do not
use a trailing zero.)
Answer: 2 mL
Follow these steps for the Ratio and Proportion method of calculation:
Step 1: What is the unit of measurement the nurse should calculate? mg
Step 2: Set up an equation and solve for X. X = Dose per kg × Client's weight in kg
X mg = 4 mg/kg × 60 kg
X mg = 240 mg
The dose is divided into three equal doses; therefore, divide X by 3. 240 mg = 80 mg3
Step 3: What is the unit of measurement the nurse should calculate? mL
Step 4: What is the dose the nurse should administer? Dose to administer = Desired 80 mg
Step 5: What is the dose available? Dose available = Have 40 mg
, Step 6: Should the nurse convert the units of measurement? No
Step 7: What is the quantity of the dose available? 1 mL
Step 8: Set up an equation and solve for X. Have/Quantity = Desired/X
40 mg/1 mL = 80 mg/X mL
X mL = 2 mL
Step 9: Round if necessary.
Step 10: Determine whether the amount to administer makes sense. If there are 40 mg/mL and
the prescription reads 4 mg/kg/day divided in three equal doses, it makes sense to administer 2
mL. The nurse should administer tobramycin 2 mL IM per dose.
Question
4. A nurse is preparing to administer meperidine 75 mg IM stat. Available is meperidine injection
100 mg/mL. How many mL should the nurse administer? (Round answer to nearest hundredth.
Use a leading zero if it applies. Do not use a trailing zero.)
Answer: 0.75 mL
Follow these steps for the Ratio and Proportion method of calculation:
Step 1: What is the unit of measurement the nurse should calculate? mL
Step 2: What is the dose the nurse should administer?
Dose to administer = Desired 75 mg
