Calcs

Question 1

How many drops are in 1ml

Answer 1

20 drops in 1ml

Question 2

Sando K tablets contain 0.6 g potassium chloride (KCl) and 0.4 g potassium bicarbonate (KHCO3) per
tablet. A patient requires potassium replacement at a dose of 200 millimoles of potassium daily.
Molar mass of potassium (K) is 39 g/mol.
Molar mass of chlorine (Cl) is 35.5 g/mol.
Molar mass of bicarbonate (HCO3) is 61 g/mol.

How many Sando K tablets are required to provide 200 millimoles of potassium daily?
Give your answer to the nearest whole number of tablets

Answer 2

Moles of KCl/tablet = mass/molar mass = 0.6 g/ (39+35.5) = 0.008 moles/tablet = 8 millimoles of potassium
and 8 millimoles of chloride.
Moles of KHCO3/tablet= mass/molar mass = 0.4 g/ (39+61) = 0.004 moles/tablet = 4 millimoles of
potassium and 4 millimoles of bicarbonate.
Therefore, the total millimoles of potassium in one tablet is 8 + 4 = 12 millimoles.
The patient requires 200 millimoles of potassium daily so we divide the total needed by the amount per
tablet to give us the required number of tablets:
200/12 = 16.6 = 17 tablets when rounded to the nearest whole tablet.
t
The correct answer is: 17

Question 3

A 10-year-old female child has a weeping infected wound. The child has been prescribed potassium
permanganate solution 1 in 4000. This product is prepared from a stock solution of 50 times this strength.
How many litres of potassium permanganate stock solution will be needed if the child uses 200 mL of the
diluted solution twice a day for 7 days?
Give your answer to three decimal places.

Answer 3

Question 4

A gastroenterology pharmacist is reviewing patients on adalimumab for a brand switch from Humira to Amgevita, as part of a local formulary
change.
The cost for both brands are shown below:

Humira £704.28 2 x 40mg pre-filled pens
Amgevita £633.60 2 x 40mg pre-filled pens

The pharmacist reviews 58 suitable patients, including 12 patients who are using Humira 40mg weekly for the treatment of Crohn’s disease, and 46
patients who are using Humira 40mg every 2 weeks for the treatment of ulcerative colitis. Of these, 7 patients who use Humira 40mg weekly and 30
patients who uses Humira 40mg every 2 weeks agree to switch.
Provided that there are no other associated charges, calculate the cost saving over 52 weeks if all consented patients are switched to Amgevita? Give your answer to the nearest pound.

Answer 4

We are only switching the consented patients i.e. 7 patients who uses
Humira weekly and 30 patients who uses Humira every 2 weeks

7 patients who use 40mg weekly = 7 syringes per week = 364
syringes over 52 weeks

30 patients on every 40mg every 2 weeks = 30 syringes every 2
weeks = 780 syringes over 52 weeks

Total number of syringes = 364 + 780 = 1,144 syringes
Humira costs: £704.28 for 2 syringes = £402,848.16 for 1,144 syringes
Amgevita costs: £633.60 for 2 syringes = £362,419.20 for 1,144 syringes
Cost saving = £402,848.16 - £362,419.20 = £40,428.96 = £40,429 (to the
nearest pound)

Exam framework: health economics
The correct answer is: 40429

Question 5

How many ng/ml is 4.6mcg/L

Answer 5

4.6mcg in 1000ml
0.0046mcg in 1ml
(x1000), 4.6ng in 1ml

Question 6

2) You are required to extemporaneously prepare an oral solution of magnesium sulphate
for a 24-year-old patient. The prescriber has requested that you supply magnesium sulphate
oral solution at an intermediate concentration, such that the patient can dilute 5mL of the
concentrate with 55mL of water to produce a 0.7% w/v solution. You currently have a 30%
w/v magnesium sulphate concentrate in stock.
Calculate the volume of magnesium sulphate concentrate needed to produce 300ml of the
intermediate solution.

Answer 6

Answer: 84ml
5ml diluted with 55ml of water. Total volume 60ml hence dilution factor (60 ÷ 5 = 12)
Intermediate conc: 12 x 0.7 = 8.4% w/v
C1 x V1 = C2 x V2 (30 x ? = 8.4 x 300)
V1 = 84ml

Question 7

Mr. A, a 67-year-old man admitted to the ICU, is prescribed an infusion of dopamine
at 5 micrograms per kilogram per minute (mcg/kg/min). His weight is 83 kg.
Dopamine is supplied as 200 mg in 50 mL of glucose 5 % infusion. The nurse needs
to set the syringe pump in mL/hour to deliver the correct dose.
Calculate the infusion rate in mL/hour required for Mr. A. Give your answer to one decimal place.

Answer 7

The correct answer is 6.2 mL/hour
Calculate the required dose in micrograms per minute
5mcg x 83kg = 415mcg/min
Convert to mg/hour
415mcg / 1000 = 0.415mg/min
0.415mg x 60 = 24.9mg/hour
Concentration
200mg → 50mL
24.9mg → X
X = (24.9 x 50) / 200 = 6.225 mL / hour

Question 8

A patient is receiving a continuous infusion of midazolam via a syringe driver.
The prescription is for 2.5 mg/hour over 24 hours. Midazolam is available as a 5mg/mL solution. The syringe driver has a total barrel volume of 22 mL and acalibrated length of 55 mm.
Calculate the rate, in mm/hour, at which the syringe driver should be set todeliver the required dose. Round your answer to the nearest whole number

Answer 8

The correct answer is 1mm/hour
Convert dose to volume (mL/hour)
5mg → 1mL
2.5mg → X
(2.5 x 1) / 5 = 0.5mL/hour
Convert required volume per hour into barrel length (mm/hour)
22mL → 55mL
0.5mL → X
(0.5 x 55) / 22 = 1.25 mm/hour
Round to the nearest whole number
1.25 = 1mm/hour to the nearest whole number
1mm/hour

Question 9

Mrs A is being treated in the infectious-diseases unit for hospital-acquired
pneumonia. The consultant wants to switch her to a high-dose continuous
meropenem infusion because her creatinine clearance is > 120 mL min⁻¹. Pharmacy protocol states the full 24-h dose of 2 g must be dissolved in sufficient diluent so that the final concentration is 0.08 mol L⁻¹ to reduce line occlusion. Meropenem powder has a molecular weight of 383 g mol⁻¹ and comes in 1 g vials. Nurses use standard
1-litre elastomeric pumps.
Calculate the total volume, in mL, of infusion solution required to achieve the 0.08 mol L⁻¹ concentration. Give your answer to the nearest whole number

Answer 9

Moles = Mass / RMM
Moles = 2/383 = 0.00522 mol
Determine the required volume for the target concentration (0.08 mol/L)
Volume (L) = moles / concentration
Volume = 0.00522 / 0.08 = 0.006525L
Convert to millilitres (multiply by 1000)
0.06525 L x 1000 = 65.25mL
65mL rounded to the nearest whole number

Question 10

A patient on the OPAT service needs a single 400 mg dose of teicoplanin for home administration. Teicoplanin is supplied only as 200 mg powder vials with a displacement volume of 0.28 mL per vial. Each vial is routinely reconstituted with 3mL of water for injection.
For safety, the entire contents of two reconstituted vials are drawn into one syringe before any further dilution.
Calculate the total volume, in mL, that will be drawn into the syringe from the
two reconstituted vials. Give your answer to two decimal places.

Answer 10

Question 8
The correct answer is 6.56mL
Reconstitute one 200 mg vial
Diluent added: 3 mL water for injection
Displacement volume of teicoplanin powder: 0.28 mL
Final volume per vial = 3mL + 0.28mL = 3.28mL
Draw up two vials for the 400 mg dose
Volume from two vials = 2 x 3.28mL = 6.56mL
6.56mL

Question 11

A bespoke 1-litre parenteral-nutrition (PN) bag is being modified by adding two extra
electrolytes. The admixture will contain calcium 20 mmol supplied as calcium
gluconate; for osmolarity purposes each millimole of calcium gluconate is counted as
one osmotically active particle.
It will also contain phosphate 30 mmol supplied as sodium phosphate, which
dissociates so that each millimole yields two osmotically active particles. No other
component of the PN bag is altered, so the baseline osmolarity remains unchanged.
Calculate the extra osmolarity contributed by these electrolytes alone and
express your answer in mOsm L⁻¹, rounded to the nearest whole number.

Answer 11

The correct answer is 80 mOsm L⁻¹
Calculate osmolarity contribution from calcium ions
Calcium gluconate assumed monovalent for osmolarity, therefore;
20 mmol × 1 particle mmol⁻¹ = 20 mOsm
Calculate osmolarity contribution from phosphate ions
Sodium phosphate dissociates to give two osmotically active particles, therefore,
30 mmol × 2 particles mmol⁻¹ = 60 mOsm
Add the two contributions
20 mOsm + 60 mOsm = 80 mOsm
80 mOsm L⁻¹

Question 12

You receive a prescription for nitrofurantoin oral suspension at a dose of 50 mg four times a
day for seven days. The suspension is available as 25 mg/5mL.
What is the total volume of suspension in mL that is required for the prescribed
course? (RPS 21)

Answer 12

You receive a prescription for nitrofurantoin oral suspension at a dose of 50 mg four times a day
for seven days. The suspension is available as 25 mg/5mL.
What is the total volume of suspension in mL that is required for the prescribed course?
50 mg QDS = 200 mg total dose per day
Which is 10mL QDS = 40mL total quantity per day
40 x 7 days = 280 mL
Answer 280

Question 13

A 35-year-old pregnant woman is 31 weeks pregnant. She has iron-deficiency anaemia and is
prescribed intravenous Venofer® (iron). She is 5 feet 6 inches tall and weighed 61kg before her
pregnancy. The target haemoglobin (Hb) level for this patient 15 g/dL.
You also have the following information from her medical notes:
Iron: 5 micromol/L
Haemoglobin (Hb): 10.2 g/dL
BP: 132/80 mmHg
Use the extract in the resource pack
What is the total dose of intravenous iron in mL this patient should receive? Give your answer to one decimal place.

Answer 13

Using the Ganzoni equation iron deficit is 61 x (15 – 10.2) x 2.4 + 500 = 1202.72 mg
Total iron to be administered is 1202.72 ÷ 20 = 60.136 mL
To one decimal place is 60.1 mL
TOPIC: Dosage and dose regimes
The correct answer is: 60.1

Question 14

You are preparing intravenous fluids for a patient for the prevention of hypokalaemia. You need
to add 40 mmol of potassium ions to the fluid bag.
Atomic weight of potassium = 39
Atomic weight of chloride = 35.5
How many mL of potassium chloride injection 20% w/v should you add? Give your answer
to the nearest whole number. (RPS 21)

Answer 14

40 mmol of potassium ions needed
MR of KCl = 74.5
Mass = MR x Moles = 74.5 x 40 mmol = 2,980 mg
KCl injection contains 20 g in 100 mL, therefore 2980 mg in x mL
x mL = (2980 mg x 100 mL) ÷ 20,000 mg = 14.9 mL
=> 15 mL to nearest whole number
ALTERNATE METHOD:
20% = 20 g in 100 mL = 200 mg/mL therefore 2980 mg ÷ 200 mg/mL = 14.9 mL

Correct answer is 15

Question 15

You have been asked to administer 150 mg of etomidate in 1L of sodium chloride 0.9% at a rate
of 60 mcg/kg/hr for a 73 kg female patient.
Assuming 20 drops per mL, what is the whole drop rate per minute that needs to be set on the giving set? Give your answer to the nearest whole number. (RPS 21)

Answer 15

60 mcg x 73 kg = 43800 mcg = 4.38 mg
Convert to mins 4.38 mg/hr ÷ 60 = 0.07 3mg/min
so 150 mg/1000 mL = 0.073 mg/ 0.48666 mL
20 drops = 1 mL
So in 0.48666 mL = 9.73 drops
Round to whole drop = 10 drops
TOPIC: Infusion rates
The correct answer is: 10

Question 16

A 72 kg man has been admitted to the acute medical unit for investigations. He is not eating or
drinking enough and therefore is prescribed maintenance fluids.
The ward stocks glucose 5% bags and sodium chloride 0.9% in volumes of 250 mL, 500 mL, and
1000 mL.
Use the extract about Intravenous fluid therapy in adults in hospital provided in the resource pack
What is the maximum volume of water in mL that should be prescribed per day?
Give your answer to the nearest whole bag. (RPS 21)

Answer 16

Using ‘Algorithm 3: routine maintenance’, the maximum volume of fluid/water he should receive
is 30 mL/kg/day
Therefore: 30 mL/kg x 72 kg = 2160 mL
In practice you would hang a full bag of fluid so this patient should receive 2250 mL maximum.
TOPIC: Dosage and dose regimes
The correct answer is: 2250

Question 17

A solution of benzalkonium chloride is available in a concentration of 1:750 w/v.
How many mL of purified water is required to be added to 30 mL of the solution to prepare a 1:5000 solution of benzalkonium chloride for use as a wet dressing for the skin? (RPS 21)

Answer 17

1:750 = 1g in 750mL.
Therefore there will be 40 mg in 30 mL of benzalkonium solution.
Target solution is 1:5000. This is equivalent to 1 g in 5000 mL.
We need to have 40 mg in our final solution. So the total volume needed is 200 mL
40 mg/200 mL is equivalent to a 1:5000 solution.
Started with a 30 mL volume. Need to add 170 mL of water.
TOPIC: Dilution
The correct answer is: 170

Question 18

A male patient been newly diagnosed with pulmonary tuberculosis and has been prescribed
ethambutol tablets once a day as part of quadruple therapy. He is obese (BMI > 30). His height is 177.8 cm and his weight 112 kg.
Use the extract about ethambutol provided in the resource pack
What is the daily dose in mg of ethambutol in mg that should prescribed for the patient? (RPS 21)

Answer 18

Poorly wriiten equation brackets incorrect

Use the male ideal body weight formula = 50 + (2.3 x (25.4÷2.54)) = 73 kg
Adjusted body weight = Ideal body weight + (0.4 x (Actual body weight – ideal body weight))
This is: 73 + (0.4 x (112-73)) = 88.6 kg
Therefore, the daily dose is: 88.6 kg x 15 mg/kg = 1329 mg
Note the answer is 1300 mg (i.e. 3x400 mg tablets + 1x100mg) as the monograph says to the
nearest whole tablet.
TOPIC: Dose and dose regime
The correct answer is: 1300

Question 19

A 2-year-old boy is suffering from hypocalcaemia. The consultant paediatrician would like to
infuse him with 10 mmol of calcium over 12-hours. You need to make up an appropriate
intravenous infusion.
The molecular masses for compounds commonly used to make up intravenous infusions are
included below:

How many mL of calcium chloride dihydrate solution 7.35 % w/v is required to make up
the intravenous infusion? Give your answer to the nearest whole number. (RPS 21)

Answer 19

Need 10 mmol calcium (Ca2+) therefore need 10 mmol of the calcium chloride dihydrate
(CaCl2·2H2O).
Convert the molecular mass off this directly from g/mol to mg/mmol, thus 147.01 mg/mmol.
Utilise and rearrange molar equation: moles = mass ÷ molar mass => mass = moles x molar
mass
Therefore mass of CaCl2·2H2O needed is 10 mmol x 147.01 mmol/mg = 1470.1 mg.
7.35% = 7.35 g in 100 mL therefore 73.5 mg/mL, thus 1470.1 mg ÷ 73.5 mg/mL = 20 mL.
TOPIC: Molecular weight
The correct answer is: 20

Question 20

An 8-month-old child has been prescribed 25 mg/kg/dose of benzylpenicillin intravenously, four
times a day for otitis media. She weighs 11 kg. Each 200 mg vial is reconstituted to 2 mL.
What is the total dose in mL that would be administered per day?

Answer 20

25 x 11 = 275 mg/ dose.
200 mg/2 mL = 100 mg/1 mL
275 mg = 2.75 mL
Daily dose is 2.75 mL x 4 = 11 mL
TOPIC: Doses and dose regime
The correct answer is: 11

Question 21

A stroke patient is no longer able to swallow solid formulations. He was previously prescribed
100 mg phenytoin capsules at a dose of 300 mg twice a day. The doctor has now requested that
the patient changes to phenytoin suspension, still to be taken 300 mg twice a day, for 14 days.
The suspension is available in a strength of 30 mg/5 mL.
The dose equivalence is provided below:
100 mg of phenytoin capsules is equivalent to 90 mg of phenytoin suspension.
How many mL of suspension should be supplied? (RPS 21)

Answer 21

300 mg twice a day = 600 mg total dose
100 mg caps = 90 mg suspension
Therefore: 600 mg caps = 540 mg suspension
30 mg/5 mL suspension, so 540 mg would equal 90 mL daily
For 14 days total amount to supply 1260 mL
TOPIC: Dosage and unit conversion
The correct answer is: 1260

Question 22

A 59-year-old female patient with heart failure and is to start maintenance dose of intravenous
digoxin, aiming for a serum digoxin concentration of 2 micrograms. The patient is not considered
to be obese.
You have the following details:
Weight 58kg
HR: 93BPM
Creatinine: 115umol/L
Height: 5’6
BP:130/80
K+: 3.7mmol/L
Age: 59
Temp: 37C
urea: 4.1mmol/L

Use the extract about constant steady state concentration provided in the resource pack.
What is the daily dose of digoxin in mcg for this patient? Give your answer to the nearest
whole number.

Answer 22

Use actual body weight of 58 kg as patient is not obese.

Calculate creatinine clearance for women:
CrCl (mL/min) = (140–age) x weight x 1.04/115 µmol/L
CrCl = [(140 – 59) x 58 x 1.04] ÷ 115 = 42.48626 mL/min

Calculate digoxin clearance for heart failure:
DigCl (L/hr) = (0.053 x Creatinine Clearance (mL/min)) + (0.02 x IBW (kg))
DigCl = (0.053 x 42.48626) + (0.02 x 58) = 3.41177 L/hr

Need to rearrange Cpss equation to find D. Also, F becomes 1 (due to 100% bioavailable IV)
Thus: D = [Cpss x (DigCl x t)] ÷ F
D = [2.0 x (3.41177 x 24)] ÷ 1 = 163.76505 mcg
To nearest whole number is 164 mcg

TOPIC: Pharmacokinetics
The correct answer is: 164

Question 23

You are working as a pharmacist in general practice and discuss with the practice manager ways
of reducing expenditure on medicines. You review the use of nifedipine XL capsules (Coracten)
as these costs more than nifedipine XL tablets (Adipine) at an equivalent dose.

Current costs are shown below:
Adipine XL 30 mg tablets £4.70 per 28 tablets
Coracten XL 30 mg capsules £5.25 per 28 capsules

You have reviewed 50 patients who are prescribed Coracten XL capsules 30 mg twice a day and
have identified that 34 of them who can potentially switch to Adipine XL tablets 30 mg two tablets
once a day. The practice repeat prescribing policy is for 84 days of treatment per prescription.
What is the total saving for the practice for 3 repeats assuming all 34 suitable patients switch to using Adipine XL tablets?
Give your answer to the nearest pound.

Answer 23

Answer: 337

Question 24

A 33-year-old woman weighing 72 kg is prescribed a loading dose of phenytoin infusion for status epileptic.
She is 5 ft 11 inches. She has normal kidney function.
Phenytoin has a recommended dose of 20 mg/kg to be infused at a rate not exceeding 50
mg/minute. The doctor would like an infusion volume of 100 mL and a dose rate of 25 mg/minute.
Phenytoin injection is available in 5 mL ampoules containing 250 mg.
What is the flow rate in mL/min of the total infusion, including phenytoin?
Give your answer to one decimal place. (RPS 21)

Answer 24

20 mg/kg x 72 = 1440 mg
1440 mg will be in the 100 mL infusion = 14.4 mg/mL
Rate of 25 mg/min.
25 mg/min ÷ 14.4 mg/mL = 1.73611 mL/min
To one decimal place is 1.7 mL/min
TOPIC: Infusion rate
The correct answer is: 1.7

Question 25

A 29-year-old man is admitted into hospital following a drug overdose of aspirin. On admission, a plasma concentration of 68 mcg/mL is measured. The half-life of aspirin is 8 hours. What is the plasma concentration in mcg/mL after 56 hours? Give your answer to two decimal places. (RPS 21)

Answer 25

0 hours = 68mcg/mL 8 hours = 34mcg/mL 16 hours = 17mcg/mL 24 hours = 8.5 mcg/mL 32 hours = 4.25 mcg/mL 40 hours = 2.125 mcg/mL 48 hours = 1.0625 mcg/mL 56 hours = 0.53125 mcg/mL To two decimal places = 0.53 mcg/m TOPIC: Pharmacokinetics The correct answer is: 0.53

Question 26

A patient, who weighs 112 kg, has suffered an acute myocardial infarction. To achieve rapid pain relief, they are administered a 5 mg dose of morphine via intravenous bolus. Morphine has a volume of distribution of 5.2 L/kg. Calculate the initial plasma concentration, in microgram/L, of morphine. Give your answer to one decimal place. (Greenlight 23)

Answer 26

VoD = dose / C0 5 .2 L/kg x 112 kg = 5 mg / C0 582.4 L = 5 mg / C0 C0 = 5 mg / 582.4 L = 5000 micrograms / 582.4 L =8.5851648 microgram/L = 8.6 microgram/L to 1 dp Exam Framework: pharmacokinetics, dosage and unit conversions The correct answer is: 8.6

Question 27

A patient with a severe Pseudomonas infection is prescribed cefotaxime 12 g daily, in three divided doses, to be given via intravenous infusion. Cefotaxime is available in a 2 g powder for solution for injection or infusion vial. The powder for solution for injection or infusion has a displacement value of 0.7 mL/g. Two vials are each reconstituted with 10 mL of water for injection, then the contents of the vials are added to a 100 mL bag of saline. The infusion is given at a rate of 2 mL/minute. How long, in minutes, will the infusion run for each dose? Give your answer to the nearest whole minute. (greenlight 23)

Answer 27

Cefotaxime powder for solution has displacement value of 0.7mL/g therefore 2 g displaces 1.4 mL Two vials are used, so total volume displaced is 2.8 mL Each vial is reconstituted using 10mL water for injection, so 2 x 10 mL = 20 mL 20 mL water for injection + 2.8 mL displaced by powder for solution = 22.8 mL total volume in the two vials Contents of vials are added to 100 mL bag of saline. 22.8 mL + 100 mL = 122.8 mL total volume for infusion 122.8 mL administered at a rate of 2 mL/minute. 122.8mL / 2 = 61.4 minutes infusion time. Round to the nearest whole minute = 61 minutes Exam Framework: displacement volumes, infusion rates The correct answer is: 61

Question 28

A patient has bleeding oesophageal varices. They are administered a continuous intravenous infusion of octreotide at a rate of 25 microgram/hour for 5 days. Each infusion bag is prepared by diluting 500 micrograms octreotide in 60 mL saline then added to a 250 mL bag of 0.9% sodium chloride. Each bag is replaced upon completion. What is the volume, in mL, administered to the patient over the full course of treatment? You can assume the infusion is continuous with no interruption due to change of bags. (greenlight 23)

Answer 28

25 mcg/hour x 24 hours x 5 days = 3000 mcg total dose. 250mL bag + 60mL vial = 310mL contents of each bag containing 500 mcg. Each bag runs for 20 hours (500 mcg / 25mcg/hour = 20 hours) and is then replaced. Each bag is administered at a rate of 15.5mL per hour (310 mL / 20 hours = 15.5 mL/hour). 15.5 mL/hour x 120 hours = 1860 mL administered. 3000 mcg total/500 mcg/bag = 6 bags 6 bags x 310 mL = 1860 mL administered. Exam Framework: dose regimens, infusion rates The correct answer is: 1860

Question 29

A child using an insulin pump requires 22 units per day of NovoRapid insulin. Each 10 mL NovoRapid vial contains 100 unit/mL. At least 8 weeks of insulin should be supplied. How many vials of NovoRapid 100 unit/mL should be prescribed for the child? (greenlight 23)

Answer 29

22 units x 56 days = 1232 units One vial contains 100 iu/mL x 10mL = 1000 units Therefore supply 2 vials, because 1 vial is not enough to last at least 8 weeks Exam Framework: dose regimens, quantity to supply, paeds The correct answer is: 2

Question 30

A GP practice based pharmacist has been made aware of a manufacturing problem with etodolac 600mg modified-release tablets. Diclofenac 75 mg modified-release tablets will be used as an alternative until the manufacturing problem has been resolved. There are 15 patients at the practice who are prescribed etodolac 600 mg once daily. Instead, they will be prescribed diclofenac 75 mg twice daily. The cost of both medicines is shown in the table below: What is the cost difference, in £s, per week, for all 15 patients, when diclofenac is used instead of etodolac? Give your answer to two decimal places. (greenlight 23)

Answer 30

Etodolac 600 mg MR tabs = £15.50 per 30 tablets. Taken once daily, therefore (£15.50 / 30) x 7 = £3.62 weekly cost per patient (rounded to 2 dp). Diclofenac 75 mg MR tabs = £17.56 per 56 tablets. Taken twice daily, therefore (£17.56 / 56) x 2 x 7 = £4.39 weekly cost per patient. £4.39 - £3.62 = £0.77 weekly cost difference per patient, x 15 patients = £11.55 weekly cost difference for 15 patients Alternatively, calculate from daily cost: * £15.50 / 30 = £0.51666667 for etodolac * £17.56 / 56 x 2 = £0.62714286 for diclofenac * £0.62714286 - £0.51666667 = £0.1104762 cost difference per patient per day * £0.1104762 x 7 = £0.77333338 weekly cost difference per patient = £0.77 to 2 dp, x 15 patients = £11.55. * Exam Framework: Health economics The correct answer is: 11.55

Question 31

A child weighing 32 kg is administered a 50 mg intravenous bolus dose of a drug as part of pharmacokinetic testing. The peak plasma concentration is 8.76 mg/L. Volume of distribution can be calculated using the formula: What is the volume of distribution, in L/kg, of the drug? Give your answer to two decimal places. (greenlight 23)

Answer 31

Vd = 50 mg / 8.76 mg/L = 5.70776256 L = 5.71 Lto 2 dp To convert this to L/kg, divide by the child’s body weight: 5.71 L / 32 kg = 0.1784375 L/kg = 0.18 L/kg to 2dp Without rounding: 5.70776256 L / 32 kg = 0.17836758 L/kg = 0.18 L/kg to 2 decimal places Exam Framework: dosage and unit conversions, pharmacokinetics, paeds The correct answer is: 0.18

Question 32

A drug is available in a vial containing 5 g powder for solution for injection. 1 g of powder for solution for injection has a displacement volume of 1.2 mL and contains 80 mg of the drug. Each vial must be diluted with 14 mL water for injection prior to administration. What is the concentration of the drug, in mg/mL, in a reconstituted vial? (greenlight 23)

Answer 32

DV – 1.2 mL/g, so 5 g x 1.2 mL = 6 mL displaced 14 mL water is added to the vial to reconstitute. Therefore 6 mL + 14 mL = 20 mL total volume. 1 g powder for solution for injection contains 80 mg drug. Therefore 5 g contains 400 mg drug. 400 mg / 20 mL = 20 mg/mL concentration Exam Framework: displacement volume, concentrations, dilutions The correct answer is: 20

Question 33

Testosterone (molecular weight 288.4 g/mol) can be administered as an intramuscular depot injection using testosterone undecanoate (molecular weight 456.7 g/mol). Each 1 mL of solution for injection contains 250 mg testosterone undecanoate. What dose of testosterone, in mg, is given to a patient administered 4 mL of the testosterone undecanoate solution for injection? Give your answer to one decimal place. (greenlight 23)

Answer 33

1 mL of solution contains 250 mg testosterone undecanoate. In 4 mL, 1000 mg testosterone undecanoate will be administered (250 mg/mL x 4 mL = 1000 mg) 288.4/456.7 = 0.63148675 (this is the ratio of testosterone to testosterone undecanoate) 1000 mg x 0.63148675 = 631.48675 mg = 631.5 mg to one decimal place See SPC for Nebido, section 2 for same equivalent dosing info: https://www.medicines.org.uk/emc/product/3873/smpc Exam framework: Molecular weight The correct answer is: 631.5

Question 34

An aseptic pharmacist is preparing a 2.5 litre solution containing 4 mmol/L of magnesium ions. Magnesium sulphate 20% w/v is currently out of stock so the pharmacist is using magnesium sulphate 50% w/v instead. Given that the molecular weight of magnesium sulphate is 246.5, what volume of magnesium sulphate 50% w/v, in mL, will be required to prepare the solution? Give your answer to the nearest whole number. (greenlight 23)

Answer 34

1 mole magnesium sulphate= 246.5 grams 1 mmol magnesium sulphate= 246.5 mg (divide and then times by 1000) In the required solution, we need 2.5 litres x 4 mmol/L Mg ions =10 mmol magnesium ions 10 mmol of magnesium ions weigh 246.5 mg x 10 mmol = 2465 mg (i.e. 2.465g) We have 50 % w/v available, which is 50 g magnesium sulphate in 100 mL So, if 50 g in 100 ml, there is 5 g magnesium sulphate in 10 mL , and 0.5 g magnesium sulphate in 1 mL 2.465 mg / 0.5 g = 4.93 mL = 5 mL to the nearest whole number Exam Framework: molecular weight The correct answer is: 5 Or Alternative method: Step 1: Calculate total mmol of magnesium ions needed Total mmol = 4 mmol/L × 2.5 L = 10 mmol Step 2: Convert mmol to mg using molecular weight Molecular weight of magnesium sulphate (MgSO₄) = 246.5 mg/mmol Required amount in mg = 10 mmol × 246.5 mg/mmol = 2465 mg Step 3: Work out how much magnesium sulphate 50% w/v contains 50% w/v = 50 g in 100 mL = 500 mg/mL Step 4: Calculate required volume Volume (mL) = 2465 mg ÷ 500 mg/mL = 4.93 mL Final Answer: 5 mL

Question 35

A GP practice based pharmacist is calculating the potential cost saving from changing Movicol (macrogols) sachets to the alternative Cosmocol (macrogols) sachets. At the practice, there are 251 patients taking Movicol sachets. 116 of these patients are taking a dose of one sachet once a day; 107 patients are taking one sachet twice a day; and 28 patients are taking one sachet three times a day. Movicol sachets £8.11 for 30 sachets Cosmocol sachets £3.95 for 30 sachets TransiSoft sachets £21.89 for 30 sachets Laxido sachets £4.10 for 20 sachets Using the information on pricing provided, what is the cost saving, in £s, for the practice in 28 days, if all patients are changed to the equivalent dose of Cosmocol sachets? Give your answer to the nearest £5 (greenlight 23)

Answer 35

Question 36

A child weighing 20 kg requires treatment with captopril at a oral solution at a dose of 300 micrograms/kg twice daily. Captopril is available as a 5 mg/5 mL What volume of oral solution is required to deliver a single dose? Give your answer to the nearest whole number. RPS 23

Answer 36

20 x 300 = 6000 microgra ms which is equivalent to 6 mg. If the oral solution contains 5 mg in 5 mL, then 6 mg is contained in 6 mL. The correct answer is: 6

Question 37

An 83-year-old man on your ward weighs 49 kg and requires treatment with cefoxitin for a complicated urinary tract infection that has not responded to other antibiotics. He has a serum creatinine of 112 micromoles/L. You have the following information about the use of cefoxitin: Renal impairment: There is extremely little data on the administration of cefoxitin in patients with renal impairment. Great caution is advised when cefoxitin is administered to these patients. In adults with renal impairment, an initial loading dose of 2 g can be administered. After the loading dose, the following recommendations can be used as guide for maintenance treatment: Cockcroft and Gault equation: Estimated creatinine clearance in mL/min=((140-Age(years))x weight (kg) x constant)/(serum creatinine (micromol/L) ) Constant = 1.23 for men, 1.04 for women What is the maximum suggested daily maintenance dose of cefoxitin for this patient? Give your answer to the nearest whole number.

Answer 37

CrCl is 30.7mL/min therefore patient falls into category of 2 g every 8-12 hours therefore the maximum recommended dose is 2 x 3 = 6 g.

Question 38

A baby on the paediatric intensive care unit requires an infusion of dobutamine. She weighs 4.6 kg and requires a dose of 5 micrograms/kg/min. On the unit, dobutamine is available as a 0.3% w/v solution for infusion. What infusion rate in mL/hour is required for the patient? Give your answer to two decimal places. RPS 23

Answer 38

The baby requires a dose of 5 x 4.6 = 23 micrograms/min = 1380 micrograms/hour = 1.38 mg/hour. The concentration of the infusion is 0.3% w/v, therefore contains 300 mg in 100 mL, therefore 1.38 mg is contained within (1.38/300) x 100 = 0.46 mL.

Question 39

A patient on your ward requires treatment with genta micin at a dose of 6 mg/kg/day. She weighs 107 kg and is 158 cm tall. Her BMI is 43, therefore she is classed as obese. In obese patients, the dose of gentamicin must be calculated according to adjusted body weight. Adjusted body weight = ideal body weight + (0.4 x excess weight) (where excess weight = actual body weight – ideal body weight) Ideal body weight = Constant + 0.91 (Height – 152.4) * Constant = 50 for men; 45.5 for women * Height in centimetres What dose of gentamicin is required per day? Round your answer to the nearest whole number. (RPS 23)

Answer 39

Step 1: Calculate Ideal Body Weight (IBW) IBW = 45.5 + 0.91 × (158 – 152.4) IBW = 45.5 + 0.91 × 5.6 IBW = 45.5 + 5.096 = 50.596 kg Step 2: Calculate Adjusted Body Weight (AdjBW) Excess weight = 107 – 50.596 = 56.404 kg AdjBW = 50.596 + (0.4 × 56.404) AdjBW = 50.596 + 22.562 = 73.158 kg Step 3: Calculate Gentamicin Dose Dose = 6 mg/kg/day × 73.158 kg = 438.948 mg/day Final Answer: 439 mg/day ✅

Question 40

A 72-year-old patient asks to buy effervescent 500 mg paracetamol tablets at your pharmacy. These tablets contain 17.8 millimoles of sodium per tablet. The atomic mass of sodium is 23 g/mol. The WHO recommended maximum daily dietary intake of sodium is 2 g. The patient takes eight 500 mg effervescent paracetamol daily. How much more sodium would this contain than the maximum recommended daily dietary intake? Give your answer to one decimal place. RPS 23

Answer 40

Step 1: Calculate total sodium intake in mmol Total sodium = 17.8 mmol × 8 = 142.4 mmol Step 2: Convert mmol to mg 142.4 mmol × 23 mg/mmol = 3,275.2 mg = 3.2752 g Step 3: Calculate how much more than the WHO limit 3.2752 g – 2 g = 1.2752 g Final Answer: 1.3 g more than the recommended daily intake

Question 41

You are working in a pharmaceutical lab and have a stock solution of a new drug with a concentration of 35% w/v. The drug is used as a mouth wash at a concentration of 0.35% w/v. You are requested to prepare 50 mL of a solution of intermediate strength, such that those trialling the mouthwash will dilute this solution 1 in 9 to get the correct concentration immediately before use. What would be the concentration of the intermediate solution? Give you answer to the nearest whole number. (RPS 23)

Answer 41

Step 1: Understand the dilution ratio 1 in 9 dilution means the intermediate solution is diluted 1 part in a total of 9 parts → Dilution factor = 1/9 Step 2: Use the dilution equation Final concentration = Intermediate concentration × (1/9) 0.35% = Intermediate × (1/9) Step 3: Rearrange to find Intermediate concentration Intermediate concentration = 0.35% × 9 = 3.15% w/v Final Answer: 3% w/v OR Step 1: Recognise what 1 in 9 means Only 1/9 of the final solution is the intermediate solution. So, the intermediate must be 9 times stronger than the final concentration. Step 2: Multiply Intermediate concentration = 0.35% × 9 = 3.15% w/v

Question 42

A baby has been started on phenobarbital 15 mg/5 mL elixir at the maximum dose and as a result has experienced fewer seizures. The baby weighs 7.8 kg. Dosage information is provided below. RECOMMENDED DOSE AND DOSAGE SCHEDULE Usual adult daily dose: 60-200 mg phenobarbital taken in 2 or 3 divided portions. Children: initially 3-6 mg per kg body weight per day taken in 2 or 3 divided portions. Label states: for use as directed by the practitioner. Excipient warnings: This medicine contains 1.6 g of alcohol (ethanol) in each 5 mL (i.e. up to 21 g based on a 65 mL dose). The amount in 5 mL of this medicine is equivalent to 39 mL beer or 16 mL wine (i.e. up to 501 mL beer or 208 mL wine based on a 65 mL dose). The alcohol in this preparation is likely to effect children. These effects include feeling sleepy and change in behaviour. It may also affect patient's ability to concentrate and take part in physical activities. The amount of alcohol in this medicine can affect patient ability to drive or use machines. The amount of alcohol in this medicine may alter the effects of other medicines. To be taken into account in pregnant or breast-feeding women, children and high-risk groups such as patients with liver disease or epilepsy. The baby has now developed liver impairment and the medical team would like to know the concentration of ethanol received each day. Give your answer to the nearest whole number

Answer 42

Step 1: Calculate total daily dose of phenobarbital 6 mg/kg/day × 7.8 kg = 46.8 mg/day Step 2: Find volume of elixir needed to deliver 46.8 mg 15 mg → 5 mL 1 mg → 5 / 15 = 0.333 mL 46.8 mg → 46.8 × 0.333 = 15.6 mL Step 3: Calculate ethanol content from 15.6 mL of elixir 5 mL contains 1.6 g ethanol 1 mL → 1.6 / 5 = 0.32 g 15.6 mL × 0.32 g/mL = 4.992 g ethanol Final Answer: 5 g ethanol per day

Question 43

A 34-year-old woman is in renal unit and is having her electrolytes monitored closely. To support her low potassium levels, she has been prescribed Sando K effervescent tablets, two tablets to be taken three times a day for ten days. The woman has also been following instructions from her dietician and receives 10 mmol of potassium from her diet per day. The recommended daily allowance (RDA) for potassium is 3500 mg a day. Each Sando-K® tablet contains 12 mmol of potassium (K+) and 8 mmol of chloride (Cl-) Relative molecular mass of K is 39 g/mol Relative molecular mass of Cl is 35 g/mol What percentage of the womanʼs recommended daily potassium allowance is received daily from Sando K tablets and her diet? Give your answer to the nearest whole number. RPS 23

Answer 43

Step 1: Work out how many tablets per day the patient takes Step 2: Multiply tablets per day × mmol of potassium per tablet Step 3: Add any potassium from diet or other sources Step 4: Convert total mmol to mg using: 1 mmol of potassium = 39 mg Step 5: Compare the mg to the RDA, and calculate percentage: (Total mg / RDA) × 100 Step 6: Round to the nearest whole number Step 1: Total mmol from tablets 6 tablets × 12 mmol = 72 mmol Step 2: Add dietary potassium 72 mmol + 10 mmol = 82 mmol total potassium/day Step 3: Convert to mg 82 mmol × 39 mg = 3198 mg Step 4: Calculate % of RDA (3198 ÷ 3500) × 100 = 91.37% Step 5: Round to nearest whole number Final Answer: 91% of RDA

Question 44

You are working as a CCG pharmacist and are helping the practice reduce expenditure on medicines. As a result, you are reviewing the use of tamsulosin tablets which cost more than tamsulosin capsules at an equivalent dose. Tamsulosin 400 microgram tablets cost £10.47 per 30 tablets You have reviewed 35 patients who are prescribed tamsulosin tablets 400 microgram OD and have identified that 21 of them can potentially switch to tamsulosin capsules 400microgram OD. The practice repeat prescribing policy is for 28 days of treatment per prescription. The total saving for the practice for twelve repeats if 21 patients switch to using the tamsulosin capsules is £1548.0864 What is the cost of a box of 30 x tamsulosin 400 microgram capsules in pence?

Answer 44

🧮 Step 1: Work out the total cost difference per capsule £1548.0864 saving / 7056 capsules = £0.2194 saved per capsule So, tablets cost £0.2194 more per capsule than capsules. 🧮 Step 2: Work out cost of tablets per capsule Cost of 30 tablets = £10.47 Cost per tablet = £10.47 / 30 = £0.349 🧮 Step 3: Cost of capsules per capsule £0.349 (tablet) – £0.2194 (saving) = £0.1296 per capsule 🧮 Step 4: Cost of 30 capsules 30 × £0.1296 = £3.888 Convert to pence: £3.888 × 100 = 388.8 pence 389p

Question 45

You have made 150g of Coal Tar 5%w/w in White Soft Paraffin however, when you check the prescription you realise that you have misread the information and realise that a 15%w/w ointment is required. What quantity of Coal Tar do you need to add to 150g of 5%w/w Coal Tar cream in order to increase the concentration to 15%w/w (answer to 3 decimal places)?

Answer 45

Question 46

A 30g cream contains 0.1%w/w dithranol. What weight of dithranol powder should be added to increase the concentration to 1%w/w?

Answer 46

Question 47

What mass of chlorhexidine gluconate is required to manufacture a 5 litre batch of a stock solution which, when diluted 1 in 5, will become a 0.2% w/v solution?

Answer 47

Question 48

Miss K, a 15-year-old girl, is atending the oncology unit for the treatment of osteosarcoma. She is receiving a mifamurtide infusion alongside her normal chemotherapy regimen. Mis K weighs 60.1 kg and is 1.68 m tall. The oncology team have requested a dose of 2 mg/m2 . The dose is to be manufactured in the aseptic unit.

Answer 48

Answer: 91.9 mL BSA = √ (168 cm x 60.1 kg)/3600 = 1.6747138 m2 Guideline requires 50 mL to be removed from 100 mL bag to reconstitute the vial. Once reconstituted the concentration in the vial is 0.08 mg/mL. Dose required is 2 mg x 1.6747138 m2 = 3.3494276 mg Therefore 3.3494276 mg/0.08 mg/mL = 41.867845 mL contains the dose required (or 41.9 mL) Guidelines says we need to add dose volume of 41.9 mL back to the volume in the infusion bag i.e. 41.9 mL (dose) + 50 mL (infusion bag) = 91.9 mL final volume

Question 49

Answer 49

Answer: 110 patients Total number of patients on AF register = 12,000 x 5% = 600 patients on AF register If all AF patients treated with warfarin = 600/60 = 10 will benefit from it (NNT = 60) If all AF patients treated with apixaban = 600/5 = 120 will benefit from it (NNT = 5) Number of extra patients that will benefit if all patients are switched from warfarin to apixaban = 120 - 10 = 110 extra patients

Question 50

A 48-year-old female, weighing 65 kg, has been admitted to hospital with opioid induced respiratory depression. She received a single I.V. dose of 2 mL of 50 mcg/1 mL naloxone hydrochloride to reverse the effect. Her current naloxone blood concentration is 0.036 mcg/L. The volume of distribution of naloxone is 2 L/kg and it has a plasma half-life of 1.5 hours. Using the information provided, calculate how much time, in minutes, has passed since the initial IV dose was administered.

Answer 50

Question 51

AmBisome 50 mg powder for solution for infusion must be reconstituted before use. Each vial of AmBisome 50mg is reconstituted with 12 mL water for injection to provide a concentration of 4 mg/mL amphotericin B. Using the information provided, calculate the displacement volume, in mL per mg, of AmBisome. Give your answer to two decimal places.

Answer 51

Question 52

You have been asked to prepare 250 mL of carbamazepine oral suspension for an adult patient. Available in stock Campus are all the items required, except the carbamazepine 2% w/v, which you only have available as carbamazepine 3.75% w/v. The suspension is to be prepared according to the folowing formula: Carbamazepine (2% w/v) 10 mL - Citric acid monohydrate 2.5 g - Poloxamer 188 0.2 g Potassium sorbate 0.3g Propylene glycol 2.1 mL - Purified water up to 20 mL What volume of carbamazepine 3.75% w/v, in ml, wil you need to make the required suspension? Give your answer to one decimal place.

Answer 52

Answer: 66.7 mL The ‘recipe’ we’re given is to make 20 mL of the formulation, however we have to make 250mL, which is 12.5 times the ‘recipe’ (i.e. 20 mL x 12.5 = 250 mL) 10 mL of carbamazepine 2 % is needed for 20 mL, therefore 125 mL is needed for 250 mL (10 mL x 12.5) We now have two concentrations (2 % and 3.75 %) and one volume (125 mL), and we need to calculate the missing volume. C1 x V1 = C2 x V2 2% x 125 mL = 3.75% x V2 V2 = 66.7 mL Alternative working Carbamazepine 2% w/v = 2g/100mL = 200 mg/10 mL Carbamazepine 3.75% w/v = 3.75g/100mL = 375 mg/10 mL 125 mL of 2% = 2g in 100 mL, X g in 125 mL = 2.5 g X mL of 3.75% = 2.5 g i.e. 3.75 g in 100 mL, 2.5 g in X mL X mL = 66.7mL

Question 53

A seven year old girl weighing 31 kg has been brought in to A&E suffering from asthma, and a decision is made to initiate treatment with theophylline. The desired steady-state concentration is 15 ug/mL. The apparent volume of distribution (Vd) for theophylline is 0.5 L/kg* Loading dose (mg) = Cs (mg/L) x Vd (L) Using the formula and information above, what would be the most appropriate intravenous loading dose, in mg? Give your answer to one decimal place.

Answer 53

232.5 mg Vd = 0.5L/kg x 31 kg = 15.5L Loading dose = 15 mg/L x 15.5L = 232.5 mg Convert the units right boy

Question 54

Mrs C is HIV positive and weighs 83 kg. She has been admitted to hospital for an elective caesarean section and is prescribed intravenous zidovudine to prevent maternal-foetal HIV transmission. She is prescribed zidovudine 2mg/kg to be given over 1 hour in glucose 5% at a concentration of 2 mg/ml. Given that each ampoule contains a concentration solution of zidovudine at 200 mg in 20 mL, what volume of glucose 5% is required to prepare the infusion? Give your answer to one decimal lace.

Answer 54

Answer: 66.4 mL Rationale: Dose = 2 mg/kg over 1 hour Weight = 83 kg Dose Calculation: 2 mg/kg x 83 kg = 166 mg is the dose of zidovudine. Each zidovudine ampoule is 200 mg in 20 mL (equivalent to 10 mg/mL) Therefore, in terms of the dose expressed as a volume, 166 mg is in 16.6 mL of the ampoule to be used. The final infusion bag (of glucose 5%) needs to be 2 mg/mL So, for the dose of 166 mg it needs to be given in 166 mg/2 mL = 83 mL of fluid. Since the zidovudine is already a liquid, this volume (16.6 mL) needs to be taken into account of the final fluid volume. 83 mL – 16.6 mL = 66.4 mL Therefore, 66.4 mL of glucose 5% needs to be added to make the final volume

Question 55

You are reviewing the data from a clinical trial for a new analgesic drug and looking at the number needed to treat (NNT) figures in comparison with other trial data. You read that for every 100 patients treated with the trial drug, 42 will have adequate pain relief because of the drug given to them. What is the NNT for the trial drug?

Answer 55

Answer: C - 3 Rationale: NNT is the number of patients that need to be treated for one to benefit compared with a control. We have to treat 100/42, or 2.38 patients with the trial drug for one to benefit. For NNT, we always round up to the next whole number. For NNH, we always round the number down. See references below for more information on why: . Reference: https://patient.info/doctor/numbers-needed-to-treat https://www.cebm.net/2014/03/number-needed-to-treat-nnt/

Question 56

An elderly patient arrives at your clinical for her annual diabetes review. Early in the consultation, you notice the patient's glucose meter is set to give readings in mg/dL with the average reading being 135 mg/dL. You decide to change the setting on the meter and convert the current reading to UK standard units in mmol/L. What is the patient's average glucose reading in mmol/L? Give your answer to one decimal place. Molecular weight of glucose = 180 g/mol 1 dL = 100ml

Answer 56

Answer: 7.5 mmol/L 1 mol = 180 g so 1 mmol = 180 mg (divide by 1,000) 1 mmol/L = 180 mg/1,000 mL 135 mg/dL = 135 mg in 100 mL = 1,350 mg in 1,000 mL Moles = Mass/Mr Moles = 1,350 mg/180 mg = 7.5 mmol The average reading is 7.5 mmol/L

Question 57

Questions 39 and 40 relate to Mr B, a 38-year-old patient weighing 82 kg who has ben admited to hospital with an accidental paracetamol overdose. Using the information in the resource pack provided, calculate the acetylcysteine infusion rate, in ml/minute, for the first infusion. Give your answer to one decimal place.

Answer 57

Answer: 4.4 mL/minute From table, volume of acetylcysteine 200 mg/mL required is 64 mL, which should be added to 200 mL glucose infusion, and infused over 1 hour. Therefore, 264mL/hour = 4.4 mL/minute Framework: doses and dose regimens, infusion rate, resource pack

Question 58

You are a locum working in a community pharmacy; the pharmacy uses the following formula to calculate the charge for private prescriptions: Private prescription cost = (cost of medicine + 20%) + £3.50 dispensing fee per item + £3.50 additional fee for a CD 100 x senna 7.5mg tablets cost price £3.50 60 x tramadol 50mg capsules cost price £6 GTN spray 180 dose cost price £3.79 Use this formula to calculate the price of the following prescription. Give your answer to the nearest 5p Units = £

Answer 58

{[(3.50 + 6 +3.79) ÷ 100] x 20} + (3 x 3.50) + 3.50 = 13.29 ÷ 100 x 20 =13.29 + 2.658 + 14 = £29.95 Framework: Using Provided Formula, rounding The correct answer is: 29.95

Question 59

A doctor wishes to switch a child from oral suspension to capsules at the same daily dose. They have been taking Epanutin ® 30 mg/5 mL oral suspension at a dose of 30 mL twice daily. They will continue to take their dose twice daily when converted to capsules. Preparations containing phenytoin sodium are not bioequivalent to those containing phenytoin base (such as Epanutin Infatabs® and Epanutin® suspension); 100 mg of phenytoin sodium is approximately equivalent in therapeutic effect to 92 mg phenytoin base. How many phenytoin sodium 100 mg capsules will be required per day? Give your answer to the nearest whole number of capsules. (RPS 24)

Answer 59

Current dose is 30 mL twice daily. The strength of the solution is 30 mg in 5 mL, therefore in 30 mL there are 30 mg x (30/5) = 180 mg so their current dose is 180 mg twice daily. 100 mg phenytoin sodium (in the capsules) is equivalent to 92 mg phenytoin base (in the solution). We're told: 100 mg of phenytoin sodium ≈ 92 mg of phenytoin base This means: If you want the same effect as 92 mg of base, you need 100 mg of sodium. So if you're giving 360 mg of base, you’ll need more phenytoin sodium to get the same effect. Therefore, 180 mg phenytoin base is equivalent to (180/92) x 100 = 195.65 mg phenytoin sodium. Therefore, for each dose the patient will require 2 x 100 mg capsules to give the closest dose, and each day the patient requires 4 capsules in total. The correct answer is: 4

Question 60

You are working as a practice pharmacist and have been asked to help the practice reduce expenditure on medicines. As a result, you are reviewing the use of tolterodine 4 mg m/r tablets, as these cost more than tolterodine 2 mg tablets at an equivalent dose. Current costs are shown below: Tolterodine 4 mg mr tablets - £25.78 per 28 tablets Tolterodine 2 m g tablets - £2.88 per 56 tablets You have reviewed nine patients who are prescribed tolterodine 4 mg m/r tablets daily on repeat prescription and have identified that seven of them could potentially switch to using the tolterodine 2 mg tablets at a dose of one tablet twice a day. The practice has a repeat prescribing policy of 56 days treatment on a prescription. What is the total saving for the practice for six repeats assuming all seven suitable patients switch to using the tolterodine 2 mg tablets? Give your answer to the nearest pound.

Answer 60

Question 61

A premature baby, with a low birth weight of 0.565 kg, has been prescribed a vancomycin continuous infusion at a dose of 0.8 mg/kg/hour. To give this infusion, 125 mg of glucose 5%. The infusion pump rate can be set in 0.01 mL/hour vancomycin will be diluted in 30 mL increments. What volume of drug, in mL, will be administered every 12 hours? Give your answer to two decimal places (Greenlight 21)

Answer 61

Answer: 1.32 mL Dose prescribed is 0.8 mg x 0.565 kg = 0.452 mg/hour Product we’re using contains 125 mg in 30 mL, which is 0.452 mg in X mL X mL = 0.10848 mL/hour i.e. this is the rate we need to set the pump at to deliver 0.452 mg/hour – The pump is set in 0.01 mL/hour increments, therefore the hourly rate is 0.11 mL for 12 hrs (Remember: the pump will only allow you to set either 0.10 or 0.11 mL/hour). - 0.11 mL/hr x 12 hours = 1.32 mL Alternative Working Dose = 0.565 kg x 0.8 mg = 0.452 mg/hour Vancomycin infusion is 125 mg in 30 mL glucose = 4.1666667 mg/mL To calculate how many mL/hour = 0.452 mg/hour /4.166667 mg/mL = 0.10848 mL/hour - Infusion pump set in 0.01 mL/hour increments therefore practically the infusion will run at 0.11mL/hour 0.11 mL x 12 hours = 1.32 mL every 12 hours Note: If you multiply 0.10848 mL x 12 hours (without rounding to 0.01 mL increments) you get 1.30 mL, which is INCORRECT

Question 62

Epidyolex® (cannabidiol) is indicated for use as adjunctive therapy of seizures associated with Lennox- Gastaut syndrome or Dravet syndrome, in conjunction with clobazam, for patients 2 years of age and older. It is available as a 100 mg/mL oral solution, with each mL of solution containing 79 mg of ethanol. 1 unit of alcohol is equivalent to 10 mL of 96% ethanol. How many units of alcohol are contained in a 220 mg daily dose of Epidyolex®? Give your answer to two decimal places. (Greenlight 21)

Answer 62

Answer: 0.02 units Note the whole first sentence, whilst tricky to understand at first, is not actually relevant to the question. Step 1: Calculate how many mg of ethanol in each daily dose: Daily dose is 220 mg Product strength is 100 mg/mL, so a 220 mg daily dose = 2.2 mL daily (220 mg/100) We know that the product contains 79 mg per mL of ethanol. Therefore in each daily dose we have 79 mg x 2.2 mL = 173.8 mg ethanol/daily dose. Step 2: Calculate how many mg of ethanol in one unit of alcohol: 1 unit alcohol = 10 mL 96% ethanol, so 96 g ethanol in 100 mL, 9.6 g in 10 mL 1 unit alcohol therefore contains 9.6 g ethanol = 9,600 mg ethanol. Step 3: Calculate how many units of alcohol in each 220 mg daily dose 173.8 mg/9,600 mg = 0.0181 units = 0.02 units to 2 decimal places

Question 63

has presented to casualty following a deliberate overdose of A 60 year old female weighing 78 kg digoxin. She is found to have serum digoxin levels of 13.62 nanograms/mL. DigiFab® is a digoxin- specific antibody which can be used to reverse digoxin toxicity. The full neutralisation dose of DigiFab® formula: can be calculated based on serum digoxin levels, rounded to the nearest whole 40 mg vial, using the Dose (in number of vials) = serum digoxin concentration (micrograms/L) x patient weight (kg) / 100 What dose of DigiFab®, in mg, should this patient be administered? (Greenlight 21)

Answer 63

Answer: 440 mg 13.62 nanograms/mL = 13.62 micrograms/L (converting both ng to mcg and mL to L requires multiplying by 1,000 then dividing by 1,000 so you get the same number at the end). Dose from formula = 13.62 micrograms /L x 78 kg = 1,062.36 micrograms Continuing with the formula: 1,062.36 micrograms / 100 = the dose in vials = 10.6236 vials We are told the dose must be rounded to the nearest whole 40 mg vial, which would be 11 vials. 11 vials x 40 mg = 440 mg dose. Alternatively: you could say that 10.6236 vials x 40 mg = 424.944 mg, or 440 mg to the nearest 40 mg.

Question 64

A male patient has been exposed to anthrax with a severe cutaneous reaction. Guidelines state that the total treatment duration for severe infection is 60 days. Treatment is initially a fortnight of ciprofloxacin 400 mg intravenously every 8 hours, stepped down to 500mg orally every 12 hours for the remainder of treatment. Due to a stock shortage of 500mg tablets, only 250mg tablets are available. How many ciprofloxacin tablets will the patient take during their treatment for severe cutaneous anthrax? (Greenlight 21)

Answer 64

Answer: 184 tablets 60 days total treatment, minus 14 days of IV therapy = 60 - 14 = 46 days oral treatment. Oral dose is 500 mg BD in 250 mg tablets, i.e. 2 tablets BD = 4 tablets daily 4 tabs x 46 days = 184 tablets

Question 65

Sapropterin dihyrdrochloride (a drug) is prescribed for tetrahydrobiopterin deficiency (a condition) at a dose of 5mg/kg daily in three divided doses as an adjunct to dietary restriction of phenylalanine. Doses are rounded to the nearest 100 mg. A pack of 100 mg soluble tablets costs £597.22 for 30 tablets. What is the treatment cost every 4 weeks for a patient weighing 69 kg? Give your answer as a whole number to the nearest pound. (Greenlight 21)

Answer 65

Step 1: Calculate daily dose = 5 mg x 69 kg = 345 mg Given in 3 divided doses = 345 mg/3 = 115 mg per dose Round doses to nearest 100 mg as per the question, therefore each dose is 100 mg i.e. 1 tablet Step 2: 1 tablet TDS for 28 days = 1 x 3 x 28 = 84 tablets 30 tablets cost £597.22 £597.22 / 30 = £19.90733 per tablet Step 3: £19.90733 x 84 tablets = £1,672.216 = £1,672.22 per 28 days Rounded to the nearest £ = £1672 If rounding at the cost per tablet, £19.91 x 84 = £1,672.44 but this will still round down to £1672 as the nearest whole pound

Question 66

Suxamethonium is used on the neonatal intensive care unit as intubation premedication. The dosage is 2mg/kg, and suxamethonium is available in 100 mg in 2 mL vials on the neonatal unit. Bradycardia may atropine should be readily result following suxamethonium administration; therefore 10 microgram/kg available, but administered at clinician discretion. Atropine sulphate is available as a 600 microgram in 1 mL solution for injection. What volume of atropine injection, in mL, should be prepared for a premature baby weighing 2.7 kg? Give your answer to two decimal places. (Greenlight 21)

Answer 66

Answer: 0.05 mL Tip: After reading this question carefully, you will realise that you do not need the suxamethonium dose of product info. Once you disregard this, the question is straightforward. You can ignore the first two sentences. Atropine dosage = 10 microgram /kg Baby weighs 2.7kg 10 mcg x 2.7 kg = 27 mcg Atropine available as 600 microgram /mL 27 mcg / 600 mcg = 0.045 mL 0.045 mL contains 27 mcg atropine, which is 0.05 mL to 2 dp

Question 67

A vet working in the practice near your pharmacy, has asked if you can prepare an antiseptic solution for her to use when carrying out minor surgical procedures. She requires 3.5 litres of a 0.75% w/v solution. You have in stock a solution of 15% w/v antiseptic solution. What is the correct amount of water, in mL, that must be added to the 15% w/v solution in order to make sufficient solution for the vet? (Greenlight 21)

Answer 67

A vet working in the practice near your pharmacy, has asked if you can prepare an antiseptic solution for her to use when carrying out minor surgical procedures. She requires 3.5 litres of a 0.75% w/v solution. You have in stock a solution of 15% w/v antiseptic solution. What is the correct amount of water, in mL, that must be added to the 15% w/v solution in order to make sufficient solution for the vet?

Question 68

A patient, weighing 60 kg, is prescribed noradrenaline 1 mg/mL concentrate for solution for infusion at a dose of 0.2 microgram/kg/min. In order to prepare the infusion for administration via syringe pump, 2 mL of noradrenaline 1 mg/mL concentrate should be added to 48 mL 5% dextrose. A nurse has asked you to calculate what infusion rate they should set the syringe pump at, in mL/hour, to administer the noradrenaline at the prescribed rate? (Greenlight 21)

Answer 68

Answer: 18 mL/hr Dose is 60 kg x 0.2 microgram/min x 60 mins = 720 micrograms/hour = 0.72 mg/hour The noradrenaline is 1 mg in 1 mL, and we’re adding 2 mL (2 mg) to a 48 mL glucose bag. We therefore now have a glucose infusion bag containing 2 mg noradrenaline and 48 mL glucose. We now have to calculate the infusion rate, using this infusion bag, to deliver 0.72 mg/hour. 2 mg in 50 mL 0.72 mg in X mL X mL = 18 mL

Question 69

Ciclosporin 1mg/mL eye drops are used in the treatment of severe vernal keratoconjunctivitis. The drops are available as either the Ikervis® or Verkazia® brand. Ikervis® is only licensed for patients over 18 years of age, and Verkazia® is only licensed in children from 4 years of age and adolescents. Across England in 2019, there were 25,941 items of Ikervis® dispensed at a cost of £2,167,022. In comparison, 205 items of Verkazia® dispensed at a cost of £54,120. What would be the estimated total prescribing cost, in £s, if all prescriptions for ciclosporin 1mg/mL eye drops had been for Verkazia®? Give your answer to the nearest £500. (Greenlight 21)

Answer 69

Answer: £6,902,500 Verkazia costs £54,120 for 205 packs. This is £264 per pack. If all Rx’s for ciclosporin eye drops were dispensed using the Verkazia brand i.e. the 25,941 items + 205 items (26,146 items in total), the total cost would be: £6,902,544. = £6,902,500 to nearest £500

Question 70

- co-careldopa MR 25/100 mg tablets, 1 tds - bromocriptine 10 mg tablets, 1 od - entacapone 200 mg tablets, 1 tds – carbidopa and levodopa – a dopamine agonist – a COMT inhibitor The medical team have asked for your advice in converting her to a rotigotine patch. Using the information provided in your resource pack, calculate the total strength of rotigotine patches, in mg, required for Mrs G per 24 hours. (Greenlight 21)

Answer 70

Answer – 10 mg/24 hours 1. Calculate LEDD – [(A) + (B)] x 0.55 (A) is the total adjusted daily levodopa dose: - co-careldopa MR 100 mg tds = 300 mg - Total adjusted daily levodopa, due to MR preparation = 300 mg x 0.91 = 273 mg (A in the LEDD formula) (B) is the total adjusted daily dopamine agonist estimate levodopa equivalent: - Bromocriptine 10 mg daily x 10 = 100 mg (B in the LEDD formula) LEDD = [(273 mg + 100 mg)] x 0.55 = 205.15 mg 2. Calculate dosage for rotigotine patch = Adjusted LEDD/20 - 205.15 mg ÷ 20 = 10.2575 mg - Therefore a 10 mg dose of rotigotine/24 hours would be most appropriate (6 mg + 4 mg or 2mg + 8 mg patches).

Question 71

A drug has been prescribed as 600 mg twice daily for a fourteen day treatment course. It is available as a 200 mg/5 mL oral suspension, with each bottle containing 100 mL. Bottles should be supplied as whole bottles only. What volume of oral suspension, in mL, should be supplied to complete the course of treatment? (Greenlight 22)

Answer 71

Dose is 600 mg twice daily for 14 days Product is 200 mg/5 mL = 600 mg in 15 mL, so each dose is 15 mL of the oral suspension. 15 mL twice daily = 30 mL daily for 14 day course = 30 mL x 14 days = 420 mL Each bottle is 100 mL so FIVE bottles should be supplied (500 mL total volume to be supplied). Four bottles (400 mL) would be insufficient to complete the course. The correct answer is: 500

Question 72

Some patients require intravenous fluids because they are unable to take fluids orally. This may be given as a fluid bolus, or a continuous intravenous infusion. Under-dosing may lead to dehydration and renal insufficiency, while over-dosing can cause fluid overload and oedema. Maintenance fluid requirements can be calculated using the Holliday-Segar 4-2-1 rule. This formula is often used for children and can also be used for adults. Using the information in the resource provided, what would be a suitable volume of fluid, in mL, to administer to a patient weighing 72 kg over a 24-hour-period? Give your answer to the nearest 100 mL. (Greenlight 22)

Answer 72

Patient weight = 72 kg Looking at the formula for over 20 kg patient: 60 mL + 52 mL/hr = 112 mL/hr x 24 hours = 2,688 mL = 2,700 mL to nearest 100 mL Alternative: For the first 10 kg of body weight: 4 mL/kg/hr x 10 kg = 40 mL/hr For the second 10 kg of body weight: 2 mL/kg/hr x 10 kg = 20 mL/hr For subsequent kg above 20 kg = 1 mL/kg/hr x the remaining 52 kg = 52 mL/hr (72 kg – 20 kg = 52 kg) 40 mL + 20 mL + 52 mL = 112 mL/hr 112 mL/hr x 24 hours = 2,688 mL = 2,700 mL to nearest 100 mL Background info on the formula: In a study published in 1957 in the Journal of Paediatrics, Malcolm Holiday and William Segar developed a simple rule that can be easily remembered for calculating maintenance fluid in sick children. The rule helps to easily calculate the maintenance fluid needs in hospitalized patients. The correct answer is: 2700

Question 73

Five patients are prescribed pregabalin 75 mg capsules, to take one capsule twice daily. One box of 56 pregabalin 75 mg capsules costs £2.39. Due to a supply problem, pregabalin 75 mg tablets will be prescribed instead. Each box of 84 pregabalin 75 mg tablets costs £5.59. What is the additional cost per patient for a 30 day period by using tablets instead of capsules? Give your answer in pounds to the nearest penny. (Greenlight 22)

Answer 73

Cost of 75 mg pregabalin capsules: 1 capsule twice daily = 2 caps per day = 2 x 30 caps for a 30 day period = 60 capsules 56 pregabalin 75mg capsules cost £2.39 £2.39 / 56 = £0.0426785 per capsule £0.0426785 x 60 = £2.5607142 per 30 days (£2.56 to 2dp) Cost of 75mg pregabalin tablets: 1 tablet twice daily = 60 tablets per 30 day period 84 pregabalin 75mg tablets cost £5.59 £5.59 / 84 = £0.0665476 per tablet. £0.0665476 x 60 = £3.9928571 per 30 days (£3.99 to 2dp) £3.9928571 - £2.5607142 = £1.4321428 £3.99 - £2.56 = £1.43 cost difference per patient per 30 days Alternatively: Each capsule costs £0.04267 Each tablet costs £0.06654 £0.06654 - £0.04267 = £0.02387 £0.02387 x 60 = £1.4322 NB. £7.16 is the answer for all 5 patients, but the question asks for per patient The correct answer is: 1.43

Question 74

Calcium gluconate may be used in the treatment of severe acute hypocalcaemia. This is initially given as a 1-2 g slow intravenous injection, followed by continuous intravenous infusion at 50 mL/hour. The infusion is prepared by diluting 100 mL of calcium gluconate 10% in glucose 5% for a final volume of 1 litre. What is the infusion rate, in mg/minute, of calcium gluconate for continuous intravenous infusion? Give your answer to one decimal place. (Greenlight 22)

Answer 74

00 mL of 10% calcium gluconate diluted to a final volume of 1 litre (1000 mL) and administered at 50 mL/hour. 100 mL of 10% calcium gluconate contains 10 g calcium gluconate. 10 g in 1000 mL. Given at 50 mL/hour. 1000 mL / 50 mL = 20 hours infusion time for one 1L bag. 10 g / 20 hours = 0.5 g/hour = 500 mg/hour. 500 mg / 60 mins = 8.3333333 mg/min. = 8.3 mg/min to 1dp. NB. A common error is to get 83.3 mg/min, if you don’t dilute to 1000 mL and keep it as 10 g/100 mL The correct answer is: 8.3

Question 75

A 61-year-old man has been prescribed a 14-day course of capecitabine for metastatic colorectal cancer. The dose of capecitabine prescribed is 1.25 g/m 2 twice daily. The patient weighs 71 kg and is 1.83 m tall. How many 150 mg capecitabine tablets should be dispensed for the first 7 days? (Greenlight 22)

Answer 75

BSA = √183 cm x 71 kg/3600 = 1.899780 m 2 Dose = 1.25 g x 1.899780 m 2 = 2.374725 g = 2,374.725 mg/150 mg = 15.83 tablets = 16 tablets/dose = 32 tabs/day 32 tablets x 7 days = 224 tablets NB. If trainee waits to round until the end of the calculation, they will get 222 tablets, which is incorrect as not a practical number per day. Extract from GPhC Learning Points from past Assessments (www.pharmacyregultion.org) Part 1 Candidates performed less well in questions that related to: * Questions where dose rounding was required to calculate an individual dose before calculating the total supply needed. For example, if a dose of a medicine is calculated at 490 mg and the medicine is available as a 500 mg tablet, rounding should occur for an individual dose rather than at the end when calculating a 28-day supply The correct answer is: 224

Question 76

A 74-year-old woman is on the medical ward being treated for COVID-19. The guideline recommends dexamethasone 4 mg OD for a total of 10 days. Using the information in the resource provided, what would be the equivalent dose of prednisolone which the patient will receive over the 10-day course? Give your answer to the nearest whole number. (Greenlight 22)

Answer 76

Prednisolone 5 mg = dexamethasone 750 micrograms (0.75 mg) Cross multiply: (Pred 5 mg x Dex 4 mg)/0.75 mg = 26.666667 mg pred So, prednisolone 26.66667 mg = dexamethasone 4 mg, x 10 days = 266.667 mg = 267mg See: https://bnf.nice.org.uk/treatment-summary/glucocorticoid-therapy.html The correct answer is: 267

Question 77

Senokot (senna) syrup is indicated for the short-term relief of occasional constipation in patients 12 years of age and older. It is available as a 7.5 mg/5 mL liquid, with each 5 mL of solution containing 6.9 mg of ethanol. 1 unit of alcohol is equivalent to 10 mL of 96% ethanol. A patient has been prescribed Senokot syrup at a dose of 15 mg daily. How many units of alcohol will the patient receive if taking Senokot as prescribed for 28 days? Give your answer to two decimal places. (Greenlight 22)

Answer 77

Step 1: Calculate how many mg of ethanol in each daily dose: Daily dose is 15 mg Product strength is 7.5 mg/5mL, so a 15 mg daily dose = 10 mL daily of syrup The product contains 6.9 mg per 5 mL of ethanol. Therefore in each daily dose we have 6.9 mg x 2 = 13.8 mg ethanol/daily dose. Step 2: Calculate how many mg of ethanol in one unit of alcohol: 1 unit alcohol = 10 mL 96% ethanol, so 96 g ethanol in 100 mL, 9.6 g in 10 mL 1 unit alcohol therefore contains 9.6 g ethanol = 9,600 mg ethanol. Step 3: Calculate how many units of alcohol in each 15 mg daily dose 13.8 mg/9,600 mg = 0.0014375 units per day Step 4: How many units in 28 days 0.0014375 units per day x 28 days = 0.04 units to 2 dp 1. The correct answer is: 0.04

Question 78

You are working on a ward and receive a request for TPN. One of the patients has low potassium and the doctors request for them to receive a daily amount of 32mmol/L potassium via infusion. In the hospital dispensary you have Kabiven available, however, the potassium in the pre-made bag is not sufficient and requires you to add potassium chloride to reach the desired amount. You have available 3%w/v of potassium chloride infusion. Molecular weight K = 39 Molecular weight Cl = 35.5 How many mL of potassium chloride 3% infusion do you need to add to the Kabiven infusion bag to fulfil the request? Round your answer to the nearest whole number. (Propharmace 24)

Answer 78

Target potassium concentration: 32 mmol/L Kabiven already contains: 23 mmol/L Additional potassium needed: 32 - 23 = 9 mmol/L Potassium chloride 3% w/v = 3g per 100 mL Molecular weight of KCl = 39 + 35.5 = 74.5 g/mol 3 g / 74.5 = 0.04027 mol = 40.27 mmol per 100 mL That’s 0.4027 mmol per 1 mL Volume required = 9 mmol / 0.4027 mmol per mL 9 / 0.4027 = 22.35 mL Final answer: 22 mL (rounded to nearest whole number)

Question 79

You have the following glucose solutions in stock: 650mls of 2500ppm 450ml of 1 in 250 You have been asked to use equal volumes of both strengths of the glucose solutions to create 650mls of a new solution and then replace 150ml of the resulting solution with 150ml of 5%w/v glucose. What is the percentage strength of the final glucose solution produced? Give your answer to one decimal place.

Answer 79

Step 1: Convert all concentrations to % w/v 2500 ppm = 2500 mg/L = 0.25% w/v 1 in 250 = 1 g in 250 mL = 1000 mg / 250 mL = 4 mg/mL = 0.4% w/v 5% w/v = already in correct format Step 2: Mix equal volumes of 0.25% and 0.4% solutions Let’s assume we use 325 mL of each to make 650 mL. (0.25% × 325) + (0.4% × 325) = total glucose content = (81.25) + (130) = 211.25 Average % strength = 211.25 ÷ 650 = 0.325% w/v Step 3: Replace 150 mL of this mixture with 150 mL of 5% New mixture: 500 mL of 0.325% = 0.325% × 500 = 162.5 units 150 mL of 5% = 5% × 150 = 750 units Total glucose = 162.5 + 750 = 912.5 Total volume = 500 + 150 = 650 mL Final % strength = 912.5 ÷ 650 = 1.4% w/v

Question 80

A low dose of Colchicine is being tested in clinical trials to reduce the repeat incidence of heart attack. The study involves 3500 women taking standard therapy for 15 years and 3500 women taking the new trial drug for 15 years. The incidence of heart attack has been recorded and rates calculated for both groups after 15 years. It was found that women in the standard therapy group had a rate of 9.2% and the women in the Colchicine trial had a rate of 2.7%. What is the number needed to treat (NNT) for the Colchicine trial? Absolute risk reduction (ARR) = difference in the rate of an event in the treatment group compared with the control ARR = (event rate in control group) – (event rate in treatment group) Number needed to treat (NNT) = number of people needed to be treated for one to benefit NNT = 1/ARR

Answer 80

Step 1: Convert percentages to decimals Control group event rate = 9.2% = 0.092 Treatment group event rate = 2.7% = 0.027 Step 2: Calculate Absolute Risk Reduction (ARR) ARR = Control rate − Treatment rate ARR = 0.092 − 0.027 = 0.065 Step 3: Calculate Number Needed to Treat (NNT) NNT = 1 ÷ ARR NNT = 1 ÷ 0.065 = 15.38 Step 4: Round to the nearest whole number NNT = 15

Question 81

Mrs P has diarrhoea and has been advised to purchase some oral rehydration sachets. She takes one sachet three times a day for two days. Each sachet contains 0.127g of sodium chloride (NaCl) and 0.241g of potassium chloride (KCl). The molecular weights of Sodium (Na), Potassium (K) and Chlorine (Cl) are shown below. Na=23 K=39 Cl=35.5 How many millimoles of chloride does she take in total? Give your answer to one decimal place.

Answer 81

Step 1: Total grams of each salt over 6 sachets NaCl: 0.127 g × 6 = 0.762 g KCl: 0.241 g × 6 = 1.446 g Step 2: Calculate moles of each salt Molecular weight of NaCl = 23 + 35.5 = 58.5 g/mol Moles of NaCl = 0.762 ÷ 58.5 = 0.01303 mol = 13.03 mmol Molecular weight of KCl = 39 + 35.5 = 74.5 g/mol Moles of KCl = 1.446 ÷ 74.5 = 0.0194 mol = 19.4 mmol Step 3: Total moles (mmol) of chloride Each mole of NaCl and KCl contributes 1 mole of Cl⁻. Total Cl⁻ = 13.03 + 19.4 = 32.4 mmol

Question 82

You are working on a paediatric cancer ward. A consultant requests that the pharmacy prepares a special manufactured suspension so that 215 mg of erythromycin can be given as a 5 mL dose. On the ward you have a 250 mg in 5 mL erythromycin granules for oral suspension. Normally, 48 mL of water is added to 3 g of granules to produce a 60 mL bottle of suspension ready to use. How many mL of water should be added to the 3 g of granules to produce a 215 mg/5 mL suspension? Round your answer to 1 decimal place.

Answer 82

Step 1: Use ratio to calculate final volume needed. Target concentration = 215 mg in 5 mL Total amount in granules = 3000 mg (3 g) Set up proportion: 215 mg / 5 mL = 3000 mg / x mL Cross-multiply: 215x = 15000 x = 15000 / 215 x = 69.8 mL (final total volume needed) Step 2: Subtract granule volume to find water to add. Granules already displace 12 mL (60 mL final volume - 48 mL water = 12 mL granule volume) 69.8 mL - 12 mL = 57.8 mL water to add Final Answer: 57.8 mL of water

Question 83

Sodium chloride has a molecular weight of 58.5g/mol. The amount of sodium chloride contained in a solution can also be expressed in mmol/L. What is the concentration, in mmol/L, of a 0.9% sodium chloride solution? Give your answer to two decimal places.

Answer 83

The correct answer is: 153.85

Question 84

Due to a formulary change, prescriptions for branded apixaban (Eliquis) are being changed to generic apixaban. There were 3953 prescriptions for Eliquis 5mg tablets in the region in the last financial year. Each prescription for Eliquis 5mg tablets costs £53.20 and each prescription for generic apixaban 5mg tablets costs £2.83. What is the annual cost saving if all prescriptions for Eliquis 5mg tablets are changed to generic apixaban 5mg tablets? Give your answer in £’s to the nearest £5.

Answer 84

The correct answer is: 199115 Watch that rounding boy

Question 85

An 11-year old child weighing 35kg has developed systemic juvenile idiopathic arthritis. They will be prescribed ibuprofen for pain relief. The maximum recommended dose of ibuprofen is 60mg/kg daily given in four to six divided doses. The child is prescribed ibuprofen 200mg tablets. How many ibuprofen 200mg tablets will the child take over a seven day period if they are taking the maximum permitted dose?

Answer 85

Step-by-step calculation: Step 1: Calculate max daily dose 60 mg/kg × 35 kg = 2100 mg per day Step 2: Round daily dose to nearest dose divisible by 200 mg 2100 mg ÷ 200 mg = 10.5 tablets/day → can't take half a tablet So maximum full dose = 10 tablets/day = 2000 mg/day Step 3: Calculate total over 7 days 10 tablets/day × 7 days = 70 tablets Final Answer: 70 tablets Divide 10 tablets over 4 to 6 doses/day: 4 doses/day: 10 ÷ 4 = 2.5 tablets per dose → not practical 5 doses/day: 10 ÷ 5 = 2 tablets per dose → ✅ works well 6 doses/day: 10 ÷ 6 = 1.67 tablets per dose → impractical

Question 86

A neonate weighing 2.8kg is prescribed a dobutamine continuous intravenous infusion at a rate of 0.5mL/hour administered using a syringe driver. To prepare the infusion, dobutamine 5mg/mL vials are diluted with glucose 5% to a final concentration of 30mg/kg body weight in a final volume of 50mL of infusion fluid. What is the rate of infusion expressed in micrograms/kg/minute?

Answer 86

1. Calculate total dose in 50 mL: 30 mg/kg × 2.8 kg = 84 mg in 50 mL 2. Calculate how many mg are in 1 mL: 84 mg ÷ 50 mL = 1.68 mg/mL 3. Multiply by the infusion rate (0.5 mL/hour): 1.68 mg/mL × 0.5 mL/hour = 0.84 mg/hour 4. Convert to micrograms/hour: 0.84 mg/hour = 840 micrograms/hour 5. Convert to micrograms/kg/minute: 840 micrograms/hour ÷ 60 minutes = 14 micrograms/min 14 micrograms/min ÷ 2.8 kg = 5 micrograms/kg/min ✅ Final Answer: 5 micrograms/kg/min

Question 87

Anidulafungin is available as a 100mg powder for concentrate for solution for infusion. Each vial should be reconstituted using water for injection to a concentration of 3.33mg/mL. This concentrate is then subsequently diluted with sodium chloride 0.9% or glucose 5% to reach the recommended concentration for administration. The contents of the reconstituted vial should be aseptically transferred into a 100mL intravenous bag of suitable diluent prior to administration. What is the concentration, in mg/mL, of the final infusion solution? Give your answer to two decimal places.

Answer 87

Amount of drug in one vial = 100 mg Reconstitution concentration = 3.33 mg per mL Volume after reconstitution = 100 mg ÷ 3.33 mg/mL = 30 mL Diluent volume = 100 mL Total final volume = 30 mL + 100 mL = 130 mL Final concentration = 100 mg ÷ 130 mL = 0.769 mg/mL Rounded to two decimal places = 0.77 mg/mL