Examples
1. ORDER: Amoxil 60 mg PO TID
Drug available: 125 mg
5 mL
How many mL do you administer for 1 dose?
*multiply the available stock of the drug (125 mg/5mL) by the order (60 mg).
Make sure that you put the units you are trying to figure out on top (mL)
5 mL(mL is unit you want to keep)
125 mg
x 60 mg = 2.4 mL/dose
How many mL do you administer for 24 hours?
* The order is for TID which means in 24 hours, you are to give this dose 3 times.
Therefore…
2.4 mL/dose x 3= 7.2~7 mL/day
2. Order: Ampicillin 350 mg IV q6h. Mix 20 mL of D5 0.25% NS. Infuse over
20 minutes
Mix 2 mL diluent in 500 mg of Ampicillin powder
How many mL do you administer?
*multiply the available stock of the drug (500 mg/2mL) by the order (350 mg).
Make sure that you put the units you are trying to figure out on top (mL)
2 mL x 350 mg = 1.4 mL
500 mg
*the order says to mix 20 mL of D5 0.25% NS therefore…
1.4 mL + 20 mL= 21.4 mL
What is the flow rate?
60 gtt/mL
60
Drops per
mL
Multiply the amount of fluid by the drip rate
21.4 mL x 60 gtts = 64.2~ 64 gtts/min
20 min
mL
In one minute, 64 drops of the medication will fall from the drip chamber.
How do you set the pump rate?
*pumps are set at mL/hr
Multiply the amount of solution, conversion factor and time. There is 60 minutes in
1 hour so…
21.4 mL x 60 min x
1
1 hr
20 min
64mL/h
21.4mL
= 64.2~64 mL/h
3. The available solution strength is 500 mg in 500 mL. The order is to titrate the dosage from 2-5
mg/kg/hr for a patient weighing 60 kg. Calculate dosage range per hour rounding to nearest
whole number.
4. An infusion pump is to be used to administer 1550 units/hr of heparin from a solution of
500 mL D5W with 35000 units. Calculate mL/hr
Questions
1. How many tablets must be administered for the following order? Order: Lopressor 25 mg
Used with permission of Novartis AG
2. Order: Morphine 5 mg sc 30 minutes before dressing change daily
Give: __________________
Copyright Baxter International Inc.
3.
3. If a 375 mg dose is required, what volume will you draw up?
The label states that there is 500 mg/mL
Used with permission from Pfizer Inc.
4. A drug label reads 10 mg tablets. Prepare a 20 mg dose. How many tablets will you give?
5. The dosage ordered is 75mg. Solution is available 25 mg/mL. How many mL will you administer?
6. Dose ordered is 15 mg. Dose provided 30 mg tablets. How many tablets do you give?
7. A dosage of 30 mg has been ordered. Solution available is 15 mg/mL. How many mL will you
administer?
8. The available strength is 5000 units/mL. Prepare a dose of 2500 units.
9. Prepare a dose of 7.5 mg of morphine IM from the available strength of 25 mg/5 mL. How many mL will you
give?
10. Prepare a 0.2 mg dose from a solution labeled 400 mcg/mL. How many mL will you administer?
11. Infuse 2300 mL in 16 hours using a 15 gtt/mL drip factor. What is the gtt/min rate?
12. Infuse 35 mL over 20 minutes using a 15 gtt/mL drip factor.
13. An adult weighing 71.8 kg has an order to titrate between 3.5 and 6 mg/kg/hr. The solution available contains
500mg in 250 mL. Calculate dosage range per hour rounding to nearest whole number.
14. Heparin 1500 units per hour is to be infused via a volumetric pump using an IV labeled 500 mL 0.9%
sodium chloride with heparin 18,000 units. Calculate the mL/hr