Pharmacy Stage 3

A GPHC‐APPROVED CALCULATOR IS PERMITTED FACULTY OF SCIENCE AND ENGINEERING SCHOOL OF PHARMACY EXAMINATION PAPER ___________________________________________________________ Module Code: 6PY011 Module title: Pharmacy Stage 3 Examination title: Pharmaceutical Calculations Date: May 2022 Year lead: Alan Hindle Examiner: Olivia Mina Time Allowed: 1.5 hours Instructions to candidates: This is a closed book examination, which consists of 30 ‘fill in the box’ questions to be completed in 1.5 hours. Print your student number clearly in the space provided at the bottom of this page. Attempt ALL questions. The pass mark is determined by cut scoring and there is no negative marking. Write your final answer in the ‘Answer’ section at the bottom of each question, using the pre‐printed answer grid. Your final answer must be written in the answer grid using a pencil. If you wish to change an answer, rub out your first solution carefully, taking care not to smudge across the boxes, then re‐write your answer clearly. The decimal point is already placed on the answer grid. When completing the answer grid use the pre‐entered decimal point to guide you. For example, if the answer is 118 tablets, fill in the answer as shown below. For whole numbers, do not enter zeros after the decimal point. Decimal points are provided. If the answer contains a decimal point, use the decimal point that is pre‐ entered. For example, if the answer to a question is 450.5 g, fill in the answer as shown below. Do not use commas. For example, if the answer is four hundred and thirty thousand units, write this as 430 000 as shown below. However, if the answer is less than 1, then enter a ‘leading’ zero, e.g., write 0.15 mL as shown below It is an examination requirement that you show a logical working out process to arrive at a computed answer. Accordingly, even where a submitted answer is correct, it will not be awarded a mark in the absence of a logical working out method with supporting numerical data. Read the questions carefully, and ensure that all answers are expressed in the units specified in the answer box Student number: …………………………….. 1 Question 1 A patient is prescribed ‘SeeClear’ eye drops with instructions to apply 2 drops into both eyes every 6 hours, for 10 weeks. Assume there are 20 drops per ml, and a bottle of ‘SeeClear’ contains 15ml. How many bottle(s) will you need to supply? Answer bottle(s) Question 2 A prescription is received for an oral glucose tolerance test. This requires you to prepare a glucose solution containing 60g anhydrous glucose in a final volume of 400 ml. The pharmacy stocks glucose containing 25%w/v and 5%w/v anhydrous glucose respectively. How many millilitre(s) of 5%w/v must be mixed with an appropriate quantity of the 25%w/v solution to prepare the prescription? Answer M mg. g mL 2 Question 3 Mrs JK has a prescription for a portable oxygen cylinder (1960 litres [L]) and mask, with instructions to use it at a flow rate of 4L/min for the first 5 hours, reducing to 3L/min thereafter. If used continuously at the prescribed flow rates, how many litres of oxygen will remain after 8 hours? Answer L Question 4 Mrs GB who weighs 70kg has been admitted to hospital and requires treatment with an aminophylline infusion at an infusion rate of 600 micrograms/kg/hour. The nurse prepares the infusion by adding 750mg of aminophylline in 500ml of glucose 5%w/v. How many millilitre(s) of this infusion will the patient receive per hour? Answer mL 3 Question 5 Mrs F has a prescription for drug Y 5mg tablets for 8 weeks. The starting dose is 25mg once a day for 7 days followed by 20 mg once a day for 7 days, 15 mg once a day for 7 days, 10mg once a day for 7 days, then 5mg once a day for 4 weeks. How many drug Y 5mg tablet(s) should be dispensed? Answer tablet(s) Question 6 The following table summarises the results of a randomised controlled trial in which participants were randomised to receive Treatment G or Control. The primary outcome was a change of HbA1c% from 0 – 20 weeks or poor glycaemic control (over 2 years) [RR 0.85 (95% Cl 0.75‐0.96, p=0.011)]. Treatment Group No of participants Treatment G Control 2200 2190 Primary outcome achieved Yes No 940 1260 995 1195 Calculate the number needed to treat [NNT, expressed to the nearest whole number] with Treatment G compared to Control. Answer NNT 4 Question 7 A drug is required as a solution containing 5mg/ml. The drug powder suitable for preparing the solution is available with a displacement value of 0.2ml/10mg. How many millilitre(s) of the diluent should be used to prepare 100ml of the required concentration? Answer mL Question 8 Mrs BH has been self‐medicating with ‘Relief tablets’ to treat indigestion after a heavy take‐ out meal. She has been taking 2 tablets three times a day. Each tablet contains 6 mmol of sodium (Na+). How many grams of sodium (Ar Na 23) will Mrs BH receive after 3 days of treatment with ‘Relief tablets’? Give your answer to one decimal place. Answer g 5 Question 9 Child MB has been diagnosed with acute pyelonephritis and the paediatric urology team would like to initiate the patient on cefuroxime oral suspension. MB weighs 15kg and is prescribed a dose of 15mg/kg twice daily for 10 days. Cefuroxime is available in 70ml bottles containing 125mg/5ml oral suspension. How many bottle(s) of the suspension would you supply to ensure the patient is able to complete the course? Answer bottle(s) Question 10 Child R is prescribed an antibiotic suspension for a chest infection. She weighs 12kg and is prescribed a dose of 80mg/kg/day in 2 divided doses for 10 days. The suspension contains 250mg in 5ml. How many millilitre(s) of the suspension would you supply to ensure the patient is able to complete the course? Answer mL 6 Question 11 A newly qualified nurse on cardiac intensive care asks for your advice on calculating the rate of a propofol infusion for sedation. The patient weighs 75kg. The syringe driver needs to deliver a dose of 4mg/kg/hour. Propofol is available as a 10mg/ml emulsion for infusion. What rate (ml/hour) should the infusion be set to run at? Answer ml/hour Question 12 A patient is prescribed an oral calcium solution. The patient has been prescribed a dose of 8mmol to be given in a 10ml dose. How many grams of calcium chloride are needed to prepare a 200ml solution of the required concentration? [Mr CaCl2 = 111]. Give your answer to one decimal place. Answer g 7 Question 13 The formula for drug H is as follows: Drug H BP 2.5g Benzoin acid solution BP 15ml Chloroform spirit BP 15ml Water BP 15ml Syrup BP to 2000ml Mrs RE presents to you a prescription for 250ml of drug H at a dose of 10ml to be taken every 8 hours for 7 days. If the patient takes the prescribed dose, how many milligrams of drug H will Mrs RE take in total? Give your answer to one decimal place. Answer mg Question 14 A patient has been diagnosed with trachomatous conjunctivitis and has been prescribed azithromycin 1.5%w/v eye drops. The patient has been prescribed one drop to be administered in both eyes every 12 hours for 3 days. If the patient is fully compliant with the treatment, how many milligrams of azithromycin will be absorbed in total? Assume 1ml = 20 drops. Answer mg 8 Question 15 Mrs Q is prescribed 5x3ml pre‐filled disposable injections containing Novorapid 100units/ml. Mrs Q injects 15 units at breakfast, 15 units at lunch and 20 units in the evening. Assuming Mrs Q is compliant with the treatment, how many complete days will this prescription last for? Answer days Question 16 AM, a 12‐year‐old boy who weighs 35kg has been admitted into the paediatric accident and emergency department with hospital acquired pneumonia. The registrar has prescribed vancomycin at a dose of 15mg/kg every 8 hours. The maximum administration rate of vancomycin is 10mg/minute. The nurse dilutes a 1g vial in 200ml of 0.9%w/v sodium chloride and asks you what the maximum time (in minutes) over which the single dose should be given? Give your answer to one decimal place. Answer minutes 9 Question 17 An intravenous infusion is prepared by adding 12mg of a drug P to 100 ml of sodium chloride 0.9% w/v [assume no displacement]. A 60kg patient requires a dose of 600 micrograms/kg/hour administered using a standard giving set. Assuming the giving set delivers 20 drops per ml, what is the drip rate (in drops/minute) that needs to be set to deliver this dose? Answer drops/minute Question 18 You are required to prepare 22 suppositories (to fulfil a prescription for 20 suppositories), each containing 60mg of codeine phosphate, in a hard fat base, sufficient to fulfil a 1g size mould. Hard fat has identical properties to theobroma oil. The displacement value for codeine phosphate in hard fat is 1.1. How many grams of hard fat are required? Give your answer to one decimal place. Answer g 10 Question 19 The diabetic foot clinic uses 40ml sachets as an antiseptic solution. This sachet contains a combination of drug V and drug Y in a ratio, by mass, of 20:1 respectively. A 40ml‐sachet contains 0.06% w/v drug V how many milligrams of drug Y will the sachet contain? Give your answer to one decimal place. Answer mg Question 20 EM is a 13‐year‐old child who weighs 30kg. EM has been admitted to the general paediatric ward with acute asthma and is prescribed salbutamol at dose of 5 micrograms/kg/minute by continuous intravenous infusion. The nurse sets up a syringe pump containing 10mg of salbutamol made up to a final volume of 50 ml of sodium chloride 0.9% w/v. What is the infusion rate (ml/hour)? Answer ml/hour 11 Question 21 Ms GH is being treated for colorectal cancer with capecitabine tablets at a dose of 1250mg/m2 every 12 hours for 14 days, followed by a 7‐day rest period. Ms GH is 1.60m tall and weighs 60kg. Capecitabine is available as 500mg tablets. How many tablet(s) are required for the 14‐day course? Express body surface area to one decimal place throughout your calculation. Answer tablet(s) Question 22 Mrs PG is on metronidazole suspension at a dose of 400mg every 8 hours for 14 days for the treatment of clostridium difficile infection. Metronidazole suspension is available in 100ml bottles containing 200mg/5ml. How many bottle(s) of metronidazole will you need to supply for the total course? Answer bottle(s) 12 Question 23 What is the resulting concentration in % w/v if you mix 800ml of 18% w/v of drug R with 700ml of a 1 in 1600 solution of drug R? Give your answer to one decimal place. Answer %w/v Question 24 You receive a prescription from a dermatologist requesting 40g of 5% w/w cream. You have a 50g tube of 10% w/w dithranol and 40g tube of 2% w/w. How many grams of the 10% w/w should be added to an appropriate quantity of 2% w/w strength to make 40g of 5% w/w cream? Answer g 13 Question 25 How many millilitre(s) of water for injection BP should be added to a vial containing 150mg of drug Q to produce an injection with a concentration of 5mg/ml, if the displacement volume of drug Q is 0.03ml/10mg? Give your answer to two decimal places. Answer mL Question 26 A patient in the intensive care ward is prescribed lidocaine for the treatment of ventricular arrhythmias following a myocardial infarction: 100mg to be given as a bolus over a few minutes, followed by 4mg/minute for 30 minutes, then 2mg/min for 2 hours, then 1mg/min for a further 12 hours. How many grams of lidocaine hydrochloride will the patient receive in 12 hours? Give your answer to two decimal places. Answer g 14 Question 27 A patient is prescribed 500ml of potassium chloride (KCl) 0.3%w/v & sodium chloride (NaCl) 0.9%w/v solution for infusion, to be given over 8 hours. How many millimoles of chloride ions does the prescribed solution contain? Give your answer to the nearest whole number. Ar potassium = 39, sodium = 23, chlorine is 35.5 Answer mmol Question 28 What is the %v/v strength of alcohol in a mixture of 2L (litres) of 30% v/v alcohol, 4L of 50%v/v and 2L of 60% v/v alcohol? Give your answer to one decimal place. Answer % v /v 15 Question 29 Mr DY weighs 68kg and has symptomatic anaemia associated with chronic renal failure. Mr DY has been initiated on darbepoetin alfa at an initial dose of 450 nanograms/kg once a week for 4 weeks, then the dose was increased to 560 nanograms/kg once a week for 4 weeks. Darbepoetin alfa is available as 20 micrograms/0.5ml. How many millilitre(s) will Mr DY have received in an 8‐week period? Give your answer to one decimal place. Answer mL Question 30 A 76‐year‐old woman is nil by mouth and has a percutaneous endoscopic gastrostromy in situ. The dietician has recommended that the patient should be prescribed 1920kcal over 24 hours Nutrison® Energy. Nutrison® Energy contains 150kcal per 100ml. At what rate (ml/hour) should this feed be delivered? Give your answer to one decimal place. Answer ml/hour 16