N250 Medication Calculation Practice Exam (with Key)
Hours to Administer
How many hours are required to administer the following fluids at the given rates?
1. Rate: TPN 1000 ml at 30 ml/hr
Hours?
ANS: or 3 hours 20 minutes
2. Rate: D5
Hours?
NS 1000 ml at 125 ml/hr
ANS:
Drop Rate
Calculate the drop rates (drops per minute; gtt/min) for the following:
3. D5
a.
b.
c.
d.
NS at 125 ml/hr
10 gtt/ml?
15 gtt/ml?
20 gtt/ml?
60 gtt/ml?
ANS:
a.
b.
c.
d.
4. D5
a.
b.
c.
d.
31 gtt/min
42 gtt/min
125 gtt/min
NS at 75 ml/hr
10 gtt/ml?
15 gtt/ml?
20 gtt/ml?
60 gtt/ml?
ANS:
a.
b.
(remember drops must be in whole numbers)
or 13 gtts/min (no partial drops)
19 gtt/min
1
c.
d.
25 gtt/min
75 gtt/min
IV Mini Bag
Antibiotics—Intravenously
Answer these questions:
a. What is the correct drug dose?
b. What is the drop rate in gtt/min?
5.
Give amikacin 800 mg IVPB, now
Available: Amikacin 500 mg/2 ml
Set and solution: D5W 150 ml minibag and a drop factor of 15 gtt/ml set
D5W 500ml
Instructions: Infuse over 60 min
a. Drug dose?
b. Drop rate?
ANS:
a.
b.
Buretrol
or 38 gtts/min
6.
Give nafcillin 250 mg IVPB q4h
Available: Nafcillin 500 mg and 1.8 ml diluent to yield 2 ml
Set and solution: Buretrol with a 60 gtt/ml drop factor and NS (normal saline) 500 ml
Instructions: Dilute in 50 ml and infuse over 30 min
a.
b.
Drug dose?
Drop rate?
Where you find the drop factor
on the IV tubing package
ANS:
a. 1 ml (500mg/2ml = 250mg/1ml)
b. 51ml X 60gtt/ml = 102 gtt/min
30 min
7.
Give tobramycin (Nebcin) 60 mg IVPB q6h
Available: See label below
Set and solution: 50 ml bag D5W and a set with a 15 gtt/ml drop factor
Instructions: Dilute with 50 ml and infuse over 30 min
2
a.
b.
Drug dose?
Drop rate?
ANS:
a. 1.5 ml (80mg/2ml = 40mg/1ml; 60mg = 1.5 ml)
b. 51.5 ml X 15 gtt/ml = 25.75 gtt/min = 26gtt/min
30 min
8.
Give cephradine 1 g IVPB q6h
Available: Cephradine 500 mg, add 4.5 ml diluent to each vial to yield 5 ml/vial
Set and solution: 50 ml bag of D5W and a set with a 15 gtt/ml drip factor
Instructions: Infuse over 30 min
a.
b.
Drug dose?
Drop rate?
ANS:
a. 10 ml (500mg/5ml = 100mg/ml; 1000mg = 10ml)
b. 60ml X 15gtt/ml = 30 gtt/min
30 min
9.
Give oxacillin 250 mg IV q4h
Available: See label below
3
Set and solution: 100 ml bag of D5W and a set with a 20 gtt/ml drop factor
Instructions: Infuse over 1 hour
a. Drug dose?
b. Drop rate?
ANS:
a.
1.5 ml (250mg/1.5ml)
b.
101.5 ml X 20gtt/ml = 33.8333 gtt/min = 34 gtt/min
60 min
10.
Order: Heparin units 8000, subQ, q6h
Drugs available:
a.
b.
Which heparin would you use?
How many milliliters of heparin would you give per dose?
ANS:
a.
Heparin 10,000 unit
b.
0.8 ml of heparin per dose
11.
Order: Enoxaparin (Lovenox) 30 mg, SQ, bid, post-hip surgery
Drug available:
4
a.
b.
The patient should receive Lovenox how many times a day?
How many milliliters (ml) should the patient receive per dose?
ANS:
a.
2 times a day
b.
0.3 ml per dose of Lovenox
12.
Order: Vitamin B12 500 mcg, IM, 2  per week
Drugs available:
a.
b.
Which cyanocobalamin cartridge would you use?
How many milliliters of cyanocobalamin would you give?
ANS:
a.
Cyanocobalamin 1000 mcg/ml
b.
0.5 ml of the drug
13.
Order: Kanamycin (Kantrex) 400 mg, IM, q8h
Patient weight: 90 kg
Dose parameter: 15 mg/kg/day in two or three divided doses
Drug available:
5
a.
b.
c.
d.
What is the dose parameter according to the patient’s weight?
How many milligrams would the patient receive per day?
Is the drug dose within safe dose parameters?
How many milliliters of Kantrex would you give per dose?
ANS:
a.
15 mg  90 kg = 1350 mg
b.
1200 mg of Kantrex per day
c.
Yes, dose per day (1200 mg) is less than maximum dose (1350 mg).
d.
1 g = 1000 mg; thus,
OR
DA:
14.
a.
Order: Diazepam (Valium) 10 mg, IM, stat
Drug available:
How many milliliters (ml) should the patient receive?
ANS:
a.
2 ml of diazepam
15.
Order: Prochlorperazine (Compazine) 7.5 mg, deep IM, stat
Drug available:
6
a.
How many milliliters of Compazine would the patient receive?
ANS:
a.
1.5 ml of Compazine deep IM stat
16.
a.
b.
c.
Order: Cefazolin (Ancef) 0.25 g, IM, q6h
Drug available:
How many milliliters of diluent would you add?
After reconstitution, how many milliliters of cefazolin solution would you have?
How many milliliters of Ancef would you administer per dose?
ANS:
a.
2 ml of diluent
b.
2.2 ml (= 500 mg)
c.
0.25 g = 250 mg; thus, give 1.1 ml of Ancef per dose
17.
Order: Ethambutol HCl 800 mg, PO, qid
Parameter: 15 mg/kg/day
Patient weighs 121 lb
Drugs available: Ethambutol 100 mg and 400 mg
a.
How many kilograms does the patient weigh?
b.
What is the maximum dose the patient should receive per day?
c.
Which bottle of ethambutol would you use?
d.
How many tablet(s) would you give?
ANS:
a.
121 lb ÷ 2.2 kg = 55 kg
b.
15 mg  55 kg = 825 mg/day; dose is within safe dose parameter of 825 mg/day.
c.
Ethambutol 400 mg bottle
d.
2 tablets from ethambutol 400 mg bottle per day
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18.
Order: Timolol maleate (Blocadren) 10 mg, PO, bid; then, after 2 weeks, the patient is to receive 40 mg
in two divided doses
Drug available:
a.
b.
c.
d.
Which bottle of Blocadren would you choose for the first 2 weeks?
How many tablet(s) should the patient receive per dose during the first 2 weeks?
Which bottle of Blocadren would you choose after the first 2 weeks? Why?
How many tablet(s) should the patient receive per dose after the second week?
ANS:
a.
Blocadren 10 mg
b.
1 tablet of Blocadren of 10 mg
c.
Blocadren 20 mg; fewer tablets to give
d.
1 tablet of Blocadren of 20 mg
19.
Order: Phenytoin (Dilantin) 1 g, PO, loading dose (LD) in three divided doses in 24 hr
Parameter: 15 to 18 mg/kg/LD
Patient weighs 60 kg
Drug available: Dilantin 100 mg capsule
a. In 24 hr, three divided doses would be every _____.
b. How many milligrams would the patient receive per dose in 24 hr?
c. Is the dose within safe parameters? Explain.
d. How many capsule(s) would you give per dose?
ANS:
a. 8 hours (q8h)
b. Per dose: (1) 300 mg, (2) 300 mg, and (3) 400 mg
c. Yes, the dose is within safe dose parameters (900–1080 mg). Parameters: 15 mg
 60 = 900 mg; 18 mg  60 = 1080 mg
d. (1) 3 capsules, (2) 3 capsules, and (3) 4 capsules
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20.
Order: Doxycycline monohydrate (Vibramycin) 100 mg, PO, initially; then 100 mg, PO, in two divided
doses per day
Drug available:
a. How many milliliters (ml) should the patient receive initially?
b. How many milligrams (mg) should the patient receive per dose after the initial
dose?
c. How many milliliters (ml) should the patient receive per dose after the initial
dose?
ANS:
a. 20 ml initially
b. 50 mg
c. 10 ml
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