Microsoft word - sample calculation problems 0806.doc

Sample Medication Calculation Problems
(Need practice with IV calculations? Scroll farther down for IV
Calculation Problems)
Do as many or as few as you need to increase your confidence in nursing calculations Problem #1
Your 4 year old pediatric patient weight 40 pounds. She is febrile. You need to
administer acetaminophen (Tylenol) 15mg/kg. How many mg will you administer?
(answer on next page)
Problem #2
The acetaminophen (Tylenol) packages come in liquid form 160 mg/5 mL. How many
mL will you administer to your 40 pound patient?
(answer on next page)

Problem #3
Your patient has an order for terbutaline (Brethine) 0.25 mg subcut. The pharmacy
delivers a syringe with 1mg/mL. How much will you waste in order to give the correct
dose?
(answer on next page)

Problem #4
Your hospice patient has an order for 7.5 mg of oxycodone (OxyContin) q 6
hours PRN. The tablets provided are 15 mg tablets. How many tablets will you
give for each dose?
(answer on next page)

Problem # 5
You receive an order for 60 mg of meperidine (Demerol) IM for your post surgical
patient. The injectible syringe is pre-packaged with 75 mg/ mL. How much will
you administer?
(answer on next page)

Problem #6
Your patient has been receiving digoxin (Lanoxin)125 mcg Q AM. Today his doctor writes a new order: How many 125 mcg tablets will you administer?
(answer on next page)
Problem #7
Your patient has an order for vasopressin (Pitressin) 5 units subcut TID You have on hand a 0.5 mL vial labeled 20 units/mL (answer on next page)


Answer to Problem #1

First convert 40 pounds into kilograms.
Method #1: Ratio Proportion
Method #2: Formula Method

2.2x = 40
x = 18.18 kg
Since you will administer 15mg of acetaminophen per 1 kg, you should multiply
15mg with the weight of 18.18 kg.
15mg x 18.18kg = 272.7.
You will administer 272.7 mg.

Answer to Problem #2
(You know you need 272.7 mg from the previous question)
Method #1: Ratio Proportion
Method #2: Formula Method

160 x = 1363.5
x = 8.521875 mL
Round. You will administer 8.5 mL.
You will administer 8.5 mL.


Answer to Problem #3

Method #1: Ratio Proportion
Method #2: Formula Method

Since you are given a syringe with 1 mg/mL and you only need 0.25 mg, then
you also just need 0.25 mL. You need to dispose (waste) 0.75 mL when the
syringe is filled 1 mL and then administer the rest of the syringe to the patient.
You will waste 0.75 mL.

Answer to Problem #4

Method #1: Ratio Proportion
Method #2: Formula Method
x = 0.5 tablet

You will administer one-half a tablet.


Answer to Problem #5

Method #1: Ratio Proportion
Method #2: Formula Method
75 x = 60
x = 0.8 mL

You will administer 0.8 mL.


Answer to Problem #6

Method #1: Ratio Proportion
Method #2: Formula Method
x= 2 tablets

x = .0.25/0.125
x = 2 tablets
You will administer 2 tablets.


Answer to Problem #7

Method #1: Ratio Proportion
Method #2: Formula Method
x= 0.25 mL

x = 5/20
x = 0.25 mL

You will administer 0.25 mL of vasopressin.

Remember, the amount in the vial (in this case 0.5 mL) does not enter into the
calculation. The important point is the concentration (the amount of drug per
mL).
IV Calculations


IV Problem #1
Your patient has an IV ordered to be delivered at a rate of 150mL/ hr. Your infusion set
delivers 15 gtt (drops)/mL. How many drops per minute will you set the IV for?
(answer on next page)

IV Problem #2
Your patient has an IV ordered to be delivered at 75mL/hr. The infusion set delivers 10
gtt (drops)/mL. How many drops per minute will you set the IV for?
(answer on next page)




IV problem #1

Rationale:
Volume to be infused (mL) x drip rate = # gtt/min 60 minutes
150 x 15 = 2250 = 37.5; or round to 38 drop per minute
60

OR
60-minute Clock Method

¦ 10 gtts/mL
Ÿ 15 gtts/mL
60 divided by 15 = 4
Divide mL/hr by 4.
that with a 60 gtts/mL drip set, the number of mL/hr = the number of gtts/min)
150 = 37.5; round to 38 drops per minute
4
IV problem #2
75 x 10 = 750 = 12.5; round to 13 drops per minute
60 60
60-minute Clock Method

¦ 10 gtts/mL
60 divided by 10 = 6
Divide mL/hr by 6
that with a 60 gtts/mL drip set, the number of mL/hr = the number of gtts/min)
75 = 12.5; round to 13 drops per minute
6

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