LPN INTENSIVE CALCULATIONS�� SPECIAL CLASS 3 ��� INTENSIVE GPHC Exam revision � programme
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QUESTION 1
In your pharmacy you have a stock solution of chlorhexidine with a concentration of 12% w/v . Chlorhexidine is used as a mouthwash at a concentration of 0.25% w/v. You are required to supply 250 mL of an intermediate strength, such that when the patient dilutes this solution 1 in 20, they obtain the correct concentration immediately before use.
How many mL of stock solution is required to make the 250 mL intermediate strength solution to be supplied?
Round your answer to the nearest 5ml.
ANSWER 1
C1V1 STOCK = C2V2 INTERMEDIATE
12 X V1 = 5 X 250 note C2 = 0.25 x 20 dilution factor
V1 = 5 X 250
12
V1 = 104.1ML
ANSWER = 105ml to nearest 5ml
QUESTION 2
Alfie a male child weighs 3kg . He is to be treated with dexamethasone via a dose reduction regimen . Calculate how many tablets of dexamethasone 0.5mg soluble tablets you would supply to complete the 28-day course. The patient complete 2 weeks of treatment before quitting due to side effects. Calculate the % adherence. Answer as a whole number.
ANSWER 2
= Total = 315 tablets
QUESTION 3
The GP surgery where you work has asked you to review their proprietary prescribing and identify any cost savings. From the practice data , you notice that they have prescribed 1176 LIPITOR 20mg tablets over the last 3 months at a cost of 465.36 pounds . You obtain the following information from the drug tariff.
Generic Atorvastatin 20mg tablets - 81 pence for 28 tablets
How much would be saved monthly if the patients on Lipitor were switched to generic atorvastatin 20mg tablets.
Give your answer to nearest pound
ANSWER 3
QUESTION 4
Grace is a 3-month-old child weighing 12.1kg. The doctor has prescribed omeprazole 2mg/ml oral suspension sugar free at a dose of 0.65mg/kg/day using a 5ML syringe as shown in the picture underneath. Calculate the volume Grace will use in a month (28 days).
ANSWER in ml to 1.d.p
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ANSWER 4
0.65mg/kg/day
0.65 X 12.1mg = 7.865mg per day
2mg = 1ml
7.865 = 3.9325ml
ROUND TO NEAREST 0.1ml as per syringe marking
3.9 x 28 = 109.2
ANSWER = 109.2ml
QUESTION 5
Ms. B is a palliative care patient who has been prescribed 60mg morphine sulphate modified release (ZOMORPH) capsules twice daily. The doctor wishes to prescribe medication for breakthrough pain and asks you to calculate the required volume.
What is the minimum entire dosage volume in ml of morphine sulphate 10mg/5ml oral solution that Ms. B should be prescribed for a month given that she takes her breakthrough pain dose every four hours on alternate days?
Answer in ml to nearest five.
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ANSWER 5
QUESTION 6
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QUESTION 6 ANSWER
WORKING
QUESTION 7
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ANSWER 7
QUESTION 8
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ANSWER 8
QUESTION 9
Mr. B is a 65year old man who weighs 11 stones 5lb, he regularly takes phenytoin capsules for epilepsy. He is admitted in hospital and is due to be administered phenytoin by I.V. injection over five minutes at a dose of 90mg/10kg. phenytoin injection is available as a 650mg vial which is reconstituted with 10ml of water for injections prior to administration to yield a concentration of 60mg/ml.
1 lb = 0.45kg 1 stone = 6.35kg
ANSWER 9
QUESTION 10 - IDEAL BODY WEIGHT-
Consider the following information about the patient below.
ANSWER 10 -
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