DRUG CALCULATION QUESTIONS

There have been visits to this page since 6/11/03.

I developed these questions some years back for training my pre-registration pharmacy graduates and second year pharmacy technician students, but they would be useful training tools for any pharmacists, technicians, nurses and doctors whether qualified or still training. I hope you find them useful. Any comments or queries, please email me!

© Matt Wright, Senior Pharmacist 2003.
1
  
A patient is prescribed 40mg of rifampicin orally. 100mg/5mL is available. How many millilitres should be administered?
  
0.5
2.5
2
1.5
 
   
2
  
A patient is prescribed 70mg of methotrexate intravenously. 50mg/2mL is available. How many millilitres should be administered?
   1.4
2.8
0.7
2.5
 
   
3
  
A patient is prescribed 50mg of sodium valproate orally. 200mg/5mL is available. How many millilitres should be administered?
   1.25
4
0.8
0.4
 
   
4
  
A patient is prescribed 75micrograms of fentanyl intravenously. 0.1mg/2mL is available. How many millilitres should be administered?
   1.5
1.25
1.33
0.66
 
   
5
  
A patient is prescribed 500mg of phenytoin orally which they take as Epanutin capsules. Following surgery they are being fed nasogastrically. Epanutin Suspension 30mg/5ml is available How many millilitres should be administered?
   83.33
84
83
75
 
   
6
  
A patient is prescribed Depixol 100mg every fortnight intramuscularly. Depixol is an oily depot containing flupenthixol decanoate 20mg/mL. What volume should be supplied?
  0.2
5
Trick question - Intravenously Use Only.
Change to Depixol Conc & supply 100mg/mL
 
   
7
  
A patient is prescribed 500mL sodium chloride 0.9% to be infused intravenously over 4 hours. Calculate the rate in mL/hour.
   2.08333
2
125
120
 
   
8
  
A patient is prescribed 1L dextrose 5% to be infused intravenously over 8 hours using a giving set which delivers 10 drops/mL. Calculate the rate in drops/minute.
   21
125
20.8
12.5
 
   
9
  
A patient is prescribed 500mL sodium chloride 0.9% to be infused intravenously over 2 hours using a giving set which delivers 15 drops/mL. Calculate the rate in drops/minute.
   17
25
63
62.5
 
   
10
   A patient is prescribed cyclophosphamide 0.75g/m2 intravenously. If they weigh 60kg and are 170cm tall. Calculate the dose of cyclophosphamide to be given. BSA= √(weight×height÷3600).   2.25
2.125
0.45
1.25
         
11
  
A patient is prescribed Kabiven 11 to be administered over 24 hours. What rate should the infusion be given over in mL/hour?
   100
85.5
83
84
 
   
12
  
A patient is prescribed Kabiven 9. The doctor wants to increase the potassium in the bag to 80mmol. What volume of potassium chloride 15% would you add?
   15
20
40
10
 
   
13
  
A patient is fluid restricted to 2L/24 hours. They are prescribed Kabiven 9. Kabiven 9 contains 2.4L. After how many hours will a new TPN bag be required?
   28
29
24
26
         
14
   Accident and Emergency present you with a requisition for 180mL of ethanol 50%. Do you know what it is being used for? You only stock ethanol 70% so will need to dilute it down to get 50%. How would you do this?   180mL + 70mL water and supply 180mL.
180mL + 50mL water and supply 180mL.
100mL made up to 180mL with water.
128.5mL made up to 180mL with water.
       
15
   You receive a requisition for acetic acid 4%. Do you know what it is being used for? You only stock acetic acid 33% so will need to dilute it down to get 4%. How would you do this?   97mL made up to 1L with water
7.92mL made up to 200mL with water
24mL made up to 198mL with water.
7.92mL made up to 65mL with water