LPN INTENSIVE CALCULATIONS�� TUTORIAL ONE ��� INTENSIVE GPHC Exam revision � programme FOR NOV 2025

LONDON PHARMACIST NETWORK (LPN)

INTENSIVE REVISION FOR NOV 2025

GPHC EXAM.

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TODAY’S TOPICS

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• INFUSION RATES ✅
• BODY MASS INDEX -BMI ✅
• HEALTH ECONOMICS ✅
• CREON QUESTIONS ✅
• SYNCHRONISE PRESCRIPTIONS ✅

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OPENING REMARKS

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• Book sign means resource questions
• USE LAPTOP OR DESKTOP
• CALC SESSION 1 of 10
• GET CALCULATOR. GET NOTES PAD and PEN
• PAID REVISION SESSION so , DO NOT SHARE LINK/ MATERIALS for this session.
• MENTAL BREAK 5 – 10 MINS
• YOU WILL BE SENT PRACTICE QUESTIONS AFTER SESSION
• STAY ACTIVE ATTEMPT QUESTIONS AND ASK QUESTIONS

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INFUSION RATE – SAMPLE QUESTION

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• Maria a 76-year-old woman weighing 60 kg has a gunshot to her abdomen and now urgently requires a blood plasma infusion. You are a pharmacist working in the Accident & Emergency department and have been asked to advise on the infusion for this patient. The registrar wants her to have 20ml/kg of plasma over 5 hours total.
• Calculate the IV rate in drops/min.
• Give your answer to the nearest whole number.

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SAMPLE ANSWER

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• 20ml x 60 = 1200ml
• 5 hours x 60 mins = 300 mins
• 1200ml / 300 mins
• 4ml per minute
• 20drops/ml
• 80 drops per minute

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• ANSWER 80 drops/min

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INFUSION RATES – QUESTION ONE

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You work as a hospital pharmacist. Mr. P is to be administered 1.5L of glucose 5% solution via IV over a total of 15 hours. After running for 10 hours and 25 minutes, 175ml of the fluid remain. What is the rate in drops/min that the remaining fluids need to be given so that the iv administration finishes in the required time?

Give answer to nearest whole number of drops.

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ANSWER ONE

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• 15 hours – 10hrs and 25 mins
• 4 hours and 35 minutes remaining i.e. 275 mins
• 275 mins = 175ml
• 1 min = 0.63636ml
• 1ml = 20 drops
• 0.63636 = x
• ANSWER = 13 drops/min

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INFUSION RATE – QUESTION TWO

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• Ms. P has been prescribed flucloxacillin 0.5 mg/kg/hour as treatment dose for cellulitis and it is to be administered via continuous intravenous infusion. The nurse on duty adds a 10ml ampoule containing 250mg solution of flucloxacillin into 500 mL glucose 5%. Ms. P weighs 50 kg and is 6 ft tall.
• You are required to calculate infusion rate in ml/min to 2.d.p ?

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ANSWER TWO

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25mg per hour i.e. 60 mins

0.41667mg = 1 min

10ml was added into 500ml = 510ml

250mg = 510 ml

0.41667mg = 0.8500ml

• ANSWER = 0.85ml/min

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INFUSION RATE – QUESTION THREE

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• Master. Bobby a 7-year-old weighing 10kg is to start receiving a 300ml infusion at 9pm on Saturday evening at a rate of 7.50ml per hour. Just as you are about to set up the infusion you receive instructions to change the infusion rate to ensure that the infusion finishes at 4pm on Sunday to ensure that Bobby is discharged on time as planned by the doctor. Calculate the infusion rate in ml/hr/kg you need to set the infusion to ensure it finishes at 4pm on Sunday.
• Answer as 2.D.P

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ANSWER THREE

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• STEP ONE CALCULATE time between 9pm sat and 4pm on SUN
• Between 9pm sat and 4pm Sunday is 19 hours
• 300/19 = 15.789ml per hour per 10kg
• 15.789/10 = 1.5789

Answer = 1.58ml/hr/kg

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INFUSION RATE - QUESTION FOUR

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ANSWER FOUR

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• 0.8g x 31kg = 24.8g . HENCE, 10% means 10g = 100ml THEN 24.8g = 248ml
• 0.62ml x 30 mins = 18.6ml
• 1.24ml x 30 mins = 37.2ml
• 1.86ml x 30 mins = 55.8ml
• 18.6 + 37.2 + 55.8 = 111.6ml
• 248ml – 111.6ml = 136.4ml
• 2.48ml = 1 min
• So, 136.4ml = 55 mins
• ADD UP ALL THE MINUTES 30 + 30 + 30 + 55 = answer
• ANSWER = 145 minutes TOTAL

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INFUSION RATE – QUESTION FIVE

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• Miss. K. weighs 30kg and is to receive carbamazepine intravenous infusion for the management of epilepsy at a dose of 10mg/kg/day in two divided doses. A 200mg carbamazepine vial is to be reconstituted with 5ml of water and diluted further to 100ml with glucose 5% solution. Given that each dose is to be infused over an hour, what is the infusion rate per dose in ml/min?
• ANSWER to nearest 0.1ml/min

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ANSWER INFUSION RATE FIVE -

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• 30kg x 10mg = 300mg per day
• 300mg / 2 = 150 mg per dose
• since 200mg is diluted in 100ml
• 150mg = 75ml
• 75ml = 1 hour I.e., 60 minutes
• 75ml/60 mins
• 1.25 ml/min
• ANSWER = 1.3ml

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BODY MASS INDEX

• UNIT = Kg/M2
• 1 stone = 6.35kg
• 1 pound = 0.45kg
• 1 foot = 30.48cm
• 1 inch = 2.54cm

BMI- QUESTION ONE

Mr. B a 23-year-old male is keen to lose weight and has hired a personal trainer at the local gym. He currently weighs 13 stones and is 165cm tall. Calculate how much weight in Kg, he needs to lose in order to reach a body mass index of 24.9kg/m2.

• 1 lb = 0.45kg 1 stone = 6.35kg 1 ft = 30.48cm
• Give your final answer in 1.d.p.

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BMI- ANSWER ONE

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• Weight = 13 stones = 82.55kg
• 24.9km2 = 67.79kg
• 82.55kg – 67.79kg = 14.76
• Answer is 14.8kg

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BMI- QUESTION TWO

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• Grace is a 33-year-old female patient who is planning to get married. She is keen to lose weight before her wedding day .She currently weighs 14 stone and 7lb and is 6 foot tall. Calculate how long in weeks it will take her to reach her target of 69kg if she loses 2 Lbs. per week.
• Give your final answer as nearest whole number.
• 1lb = 0.45kg 1 stone = 6.35kg 1 foot = 30.48cm

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BMI- ANSWER TWO

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• Current weight is 92.079kg
• 92.079 – 69 = 23.079kg
• Loses 0.908kg per week

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• ANSWER = 26 weeks approximately

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BMI- QUESTION THREE

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• Mrs. McDonalds a 55-year-old Patient weighs 225lbs and has a height of 170cm. She has recently started a new diet and exercise regimen and has been following it accordingly. Given that the ideal BMI is 18.5 - 24.9kg/m2 and Mrs. McDonalds loses weight according to the diet plan, how much weight in kg does she need to lose to reach an ideal BMI?
• Give your answer in kg to the nearest whole number.
• 1 lb. = 0.45kg
• 1 stone = 6.35kg

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BMI- ANSWER THREE

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• Current weight – target weight

• 101.25kg – 71.96 kg = answer

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• ANSWER = 29 kg

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BMI – QUESTION FOUR

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• Mrs. W a 55-year-old Patient weighs 190lbs and has a height of 1.70m. She has recently started a new diet and exercise regimen and has been following it accordingly. Given that the ideal BMI is 18.5 -24.9kg/m2 and she loses weight according to the diet plan, how much weight in kg does she need to lose to reach an ideal BMI?
• Give your answer in kg to the nearest 0.05kg.
• 1 lb. = 0.45kg

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BMI- ANSWER FOUR

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• CALCULATE WEIGHT DIFFERENCE
• 85.5kg – 71.96 kg
• = 13.54
• ANSWER = 13.55kg

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CREON QUESTION ONE

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• Mr. Jack a 77-year-old male had his pancreas removed due to pancreatic cancer and has to take Creon 25000 capsules as a result. He weighs 62.5kg and is 6 foot tall. Using the resource provided, calculate the maximum number of Creon capsules he can take a day to stay within the limit of lipase recommended. Do not exceed 10,000 lipase units per kg. Give your answer as whole number. 1lb = 0.45kg
• Creon 25000 Capsules - Summary of Product Characteristics (SmPC) - (emc) (medicines.org.uk)

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CREON ANSWER ONE

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• Patients weight = 62.5kg
• 62.5kg x 10000 = 625,000
• so maximum lipase per day = 625000 units
• one capsule = 25000
• 625000/ 25000 = X
• X = 25
• ANSWER = 25 capsules

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CREON QUESTION TWO

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• Mr. Raj a 59-year-old male had his pancreas removed due to pancreatic cancer and has to take Creon 25000 capsules as a result. He weighs 160 lb and is 6 foot tall. Using the resource provided, calculate the maximum number of creon capsules he can take a day to stay within the limit of lipase recommended. Do not exceed 10,000 lipase units per kg. Give your answer as whole number. 1lb = 0.45kg
• Creon 25000 Capsules - Summary of Product Characteristics (SmPC) - (emc) (medicines.org.uk)

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CREON ANSWER TWO

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• Patients weight = 72kg
• so maximum lipase per day = 720000 units
• one capsule = 25000
• x = 720000
• X = 28.8
• ANSWER = 28 capsules

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CREON QUESTION THREE

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• Mr. Jerry a 68-year-old male had his pancreas removed due to pancreatic cancer and has to take Creon 25000 capsules as a result. He weighs 320 lb and is 6 foot tall. Using the resource provided, calculate the maximum number of creon capsules he can take a day to stay within the limit of lipase recommended. Do not exceed 10,000 lipase units per kg. Give your answer as whole number. 1lb = 0.45kg
• Creon 25000 Capsules - Summary of Product Characteristics (SmPC) - (emc) (medicines.org.uk)

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CREON ANSWER THREE

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• Patients weight = 144kg
• so maximum lipase per day = 1,440,000 units
• one capsule = 25000
• x = 1440000 / 25000
• X = 57.6
• ANSWER = 57 capsules

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CREON QUESTION FOUR

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• Mrs. T a 53-year-old female had his pancreas removed due to pancreatic cancer and has to take Creon 25000 capsules as a result. She weighs 52kg and is 6 foot tall. Using the resource provided, calculate the maximum number of Creon capsules she can take a day to stay within the limit of lipase recommended. Do not exceed 10,000 lipase units per kg. Give your answer as whole number. 1lb = 0.45kg
• Creon 25000 Capsules - Summary of Product Characteristics (SmPC) - (emc) (medicines.org.uk)

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CREON ANSWER FOUR

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• Patients weight = 52kg
• so maximum lipase per day = 520000 units
• one capsule = 25000
• x = 520000
• X = 20.8
• ANSWER = 20 capsules

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HEALTH ECONOMICS QUESTION ONE

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• Amy is a 7-year-old patient who usually takes omeprazole 10mg dispersible tablets BD. He develops side-effects to the dispersible tablets, and his doctor decides to switch him to omeprazole 10mg/5ml oral suspension. Each 100ml bottle costs £49 on the drug tarrif. How much will be spent by the surgery if the doctor writes a prescription for omeprazole suspension for 28 days ? Note – original container must be dispensed.

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HEALTH ECONOMICS ANSWER ONE

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• 20mg = one day
• 10ml = 1 day
• 280ml = 28 days

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• 100ml = 49 POUNDS
• 280 but approximate to 300ml = 147

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• ANSWER = £147

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HEALTH ECONOMICS QUESTION TWO

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• You work in a GP surgery. 200 patients are prescribed one magrocol box each, every single month. 70% of them are prescribed movicol Brand (£12.00 per box) and the rest are prescribed laxido(£5.00 per box). How much would be saved per annum if 20% of patients currently prescribed Movicol are switched to laxido.
• Give your final answer to nearest £10

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HEALTH ECONOMICS ANSWER TWO

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• Formula
• Pts x duration x cost difference
• 28 x 12 X 7 = £2352
• To nearest ten pounds
• £2350

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HEALTH ECONOMICS QUESTION THREE

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You work in a GP surgery. 240 patients are prescribed one box of tamsulosin 30 tablets each, every single month. 50% of them are prescribed Flomax brand (£67.00 for 60 tablets) and the rest are prescribed Contiflo (£25.80 for 30 tablets). How much would be saved per annum if 90% of patients currently prescribed flomax are switched to contiflo.

Give your final answer to nearest hundred.

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ANSWER THREE

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• Formula
• Pts x duration x cost difference
• 108 x 12 x 7.7 = £9976.2
• To nearest hundred
• £10000

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HEALTH ECONOMICS QUESTION 4

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You work as a Pharmacist in a GP surgery. You have been asked to switch 8 eligible patients on Keppra 500mg tablets to the generic levetiracetam 500mg tablets. Out of the 8 patients, 2 patients are prescribed 120 tablets per patient every month, 5 patients are prescribed 60 tablets per patient every month and 1 patient is prescribed 30 tablets every month. Assuming Keppra 500mg costs £59 for a box of 60 tablets and generic levetiracetam costs £28 for a box of 60 tablets, calculate the cost savings per month if all eight patients are switched to generic levetiracetam. Assume boxes can be split.

Answer in pounds to nearest £5.

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• LONDON PHARMACIST NETWORK INTENSIVE CALCULATIONS

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HEALTHECONOMICS 4 ANSWER

2 PATIENTS USE 4 BOXES, 5 PATIENTS USE 5 BOXES AND 1 PATIENT USES HALF A BOX

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COST OF 9 AND HALF BOXES OF KEPPRA = 59 X 9.5 = 560.5 POUNDS

COST OF 9 AND HALF BOXES OF GENERIC = 28 X 9.5 = 266 POUNDS

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HENCE 560.5 – 266 = 294.5 POUNDS

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ANSWER = £295

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SYNCHRONISE A PRESCRIPTION- 1

You are working in a community pharmacy and one of the patients complained to you that she runs out of two of her medicines rather quickly. She would like you to mention it to her practice pharmacist during your next surgery run. See details of her medication below. Synchronise ramipril tablets

• DRUG & STRENGTH DOSE REMAINDER stock
• CITALOPRAM 20MG 1 OD 30
• CO-CODAMOL 8/500MG 2 QDS 336
• RAMIPRIL 2.5MG 1 BD 16
• LANSOPRAZOLE 15MG 1 BD 80
• LOPERAMIDE 2MG 2 QQH 192
• METFORMIN500MG 1 TDS 81
• TRAZODONE 50MG 2 OD 30
• METHOTREXATE 2.5mg TAKE 5 tablets at once 25
• (to make up total 12.5mg) MDU

SYNCHRONISE A PRESCRIPTION- ANSWER 1

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• In order to synchronise her medication,
• Calculate how many additional ramipril tablets this Patient requires.
• FIND drug with biggest number of treatment days left
• 42 DAYS OF co-codamol – 8 days of ramipril = 34
• 34 x 2 = 68 TABLETS

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SYNCHRONISE A PRESCRIPTION- 2

You are working in a community pharmacy and one of the patients complained to you that she runs out of one of her medicines rather quickly. She would like you to mention it to her practice pharmacist during your next surgery run. See details of her medication below . SYNCHRONISE lansoprazole TABLETS and methotrexate

• DRUG & STRENGTH DOSE REMAINDER STOCK - tabs
• METHOTREXATE 2.5MG 4 WEEKLY 8
• CO-CARELDOPA 12.5mg 1 QDS 240
• RAMIPRIL 2.5MG 1 OD 16
• LANSOPRAZOLE 15MG 1 BD 42
• METFORMIN 500MG 2 TDS 66
• Sodium bicarbonate 500MG 2 TDS 480
• SITAGLIPTIN 50MG 1 OD 14
• CARBOCEISTEINE 375 2 TDS 96

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ANSWER 2

• FIND HIGHEST DURATION sodium bicarb = 480/ 6 = 80days left
• lansoprazole = 21 days left
• 80 – 21 = 59
• 59 x 2 = 118
• 118 answer

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• Methotrexate = 14 days left
• 80 – 14 days = 66 days
• 4 tabs = 1 week
• X = 10 weeks approximately
• 40 tabs ANSWER

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SYNCHRONISE A PRESCRIPTION- 3

You are working in a community pharmacy and one of the patients complained to you that she runs out of one of her medicines rather quickly. She would like you to mention it to her practice pharmacist during your next surgery run. See details of her medication below . SYNCHRONISE METHOTREXATE TABLETS

• DRUG & STRENGTH DOSE REMAINDER STOCK
• CO-CARELDOPA 12.5mg 1 QDS 240
• METHOTREXATE 2.5MG 5 WEEKLY (12.5mg weekly) 15
• RAMIPRIL 2.5MG 1 OD 22
• LANSOPRAZOLE 15MG 1 BD 122
• Co-codamol 30/500 1 - 2 QDS 648
• Metformin 500MG 2 TDS 474
• SITAGLIPTIN 50MG 1 OD 14
• CREON 25000 8 PER DAY 632

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SYNCHRONISE - ANSWER 3

• highest duration is co-codamol = 81 days
• Methotrexate = 3 weeks' worth = 21 days
• Difference 81 – 21 = 60 days , about 9 weeks
• 1 week = 5 tabs
• 9 weeks = 45 tabs

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• ANSWER = 45 TABLETS

THE END

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