Dosage Calculations

75 flashcards by MentisLibrary

Seventy five worked problems with the formula, the steps and the answer for each. Tablets, volumes, weight based doses, IV pump rates, drip rates, drip concentrations, percentage solutions and unit conversions, plus the habits that catch tenfold errors before they happen.

An order calls for 500 mg. The supply on hand is 250 mg tablets. How many tablets?
2 tablets
An order calls for 0.125 mg. The supply is scored 0.25 mg tablets. How many tablets?
Half a tablet
An order calls for 750 mg. The supply is an oral suspension of 500 mg per 5 mL. What volume?
7.5 mL
An order calls for 40 mg. The vial is labeled 10 mg per mL. What volume is drawn up?
4 mL
An order calls for 1 g. The supply is 500 mg capsules. How many capsules?
2 capsules
An order calls for 0.6 g. The supply is 300 mg tablets. How many tablets?
2 tablets
An order calls for 62.5 mcg. The supply is 0.125 mg tablets. How many tablets?
Half a tablet
An order calls for 1.5 mg. The supply is 500 mcg tablets. How many tablets?
3 tablets
An order calls for 0.5 g of an oral suspension supplied as 125 mg per 5 mL. What volume?
20 mL
A patient weighs 176 pounds. What is the weight in kilograms?
80 kg
A child weighs 44 pounds. What is the weight in kilograms?
20 kg
An order is 5 mg per kg for a patient weighing 80 kg. What is the total dose?
400 mg
An order is 15 mg per kg for a 20 kg child, supplied as 100 mg per mL. What volume?
3 mL
A drug is safe at 20-40 mg per kg per day divided every 8 hours. What is the safe range per dose for a 15 kg child?
100-200 mg per dose
A 12 kg child has a maximum of 90 mg per kg per day. The order reads 400 mg three times daily. Is it safe?
No. The order totals 1200 mg per day, while the maximum is 1080 mg per day, so it must be clarified before administration
An infusion of 1,000 mL is ordered over 8 hours. What is the rate in mL per hour?
125 mL per hour
An infusion of 500 mL is ordered over 4 hours. What is the rate?
125 mL per hour
An infusion of 1,000 mL is ordered over 12 hours. What is the rate?
About 83 mL per hour
A 50 mL antibiotic piggyback is ordered over 30 minutes. What rate is set on the pump?
100 mL per hour
A 100 mL piggyback is ordered over 45 minutes. What rate is set?
About 133 mL per hour
An infusion runs at 125 mL per hour with a drop factor of 15 gtt per mL. What is the drip rate?
About 31 drops per minute
An infusion of 250 mL runs over 2 hours with a drop factor of 20 gtt per mL. What is the drip rate?
About 42 drops per minute
An infusion of 50 mL runs over 30 minutes with a drop factor of 10 gtt per mL. What is the drip rate?
About 17 drops per minute
Why does a microdrip set at 60 gtt per mL make the calculation easy?
Because the drops per minute equal the mL per hour exactly
A 1,000 mL bag is infusing at 125 mL per hour. How long will it take?
8 hours
A 500 mL bag is infusing at 80 mL per hour. How long will it take?
6 hours and 15 minutes
A 1,000 mL bag is started at 0900 and runs at 125 mL per hour. When will it finish?
1700
A bag has 400 mL remaining and is running at 125 mL per hour. How much time is left?
3 hours and 12 minutes
Heparin 25,000 units is in 500 mL. The order is 800 units per hour. What is the pump rate?
16 mL per hour
Heparin 25,000 units is in 250 mL. The order is 1,200 units per hour. What is the pump rate?
12 mL per hour