Safe Prescribing TRUST NAME: March 2011 London Specialty School of Paediatrics and Child Health

London Specialty School of Paediatrics Objectives of this session are To understand the importance of safe prescribing To become familiar with the local drug chart To learn how to prescribe for children

London Specialty School of Paediatrics Why is prescribing important? Prescribing errors are common from all grades of doctors Many clinical incidents are due to prescribing errors Prescribing errors can be fatal Prescribing for children is different to prescribing for adults

London Specialty School of Paediatrics Why is prescribing different in children? Children are not small adults Factors include: Body weight Body composition Surface area Nutritional status Organ maturation

London Specialty School of Paediatrics We will cover the following –Dose calculation based on age and weight –Prescribe fluids –Prescribe neonatal fluids

London Specialty School of Paediatrics Many medications for children come in liquid form It is usually more appropriate to prescribe in actual dose (e.g. mg) of drug rather than mls Medications have different concentrations –e.g. paracetamol can be 120mg/5ml or 250mg/5ml Importance of difference between micrograms and mgs. Use generic drug names when prescribing Prescribe sensibly - It is important to consider drug rounding Principles of prescribing for children

London Specialty School of Paediatrics Principles of prescribing for children Age and Weight All drug charts must have a recent weight and DOB Calculations of drug doses depend on age, weight or surface area of a child Medication is usually prescribed based on age or weight The correct doses should be checked in the BNFC or local guidelines

London Specialty School of Paediatrics Calculating Drug Doses- Example 1: Prescribing by weight Romeo, a 2 year old child weighs 12kg. He has a temperature of 38.5 o c How much paracetamol would you give them? Use the BNFC: Click Here In this example, we will use 15mg/Kg, every 6 hours Workings: –12Kg x 15mg/kg = 180mg four times a day (QDS) ENTER DOSE AGAINST TIME REQUIRED USE ONE ROUTE ONLY FOR EACH ENTRY REGULAR PRESCRIPTION MONTH YEAR March2011 DOSE DATE STARTCHANGE 07/03/2011 DATE 03/07/2011 DRUGOTHER INSTRUCTIONSSIGNATUREPHARMACY ROUTE ORAL PARACETAMOL15mg/kg QDSA.Doctor INITIALS AD mg mg mg mg

London Specialty School of Paediatrics Jimmy, a 4 yr old child weighs 16kg He has a mild chest infection. How much oral co-amoxiclav would you prescribe for him? Use the BNFC: Click Here Workings: –We will use the age range instead of weight –Age = 4 therefore dose = 5mls of 125/31 suspension three times per day (TDS) Calculating Drug Doses- Example 2: Prescribing by age ENTER DOSE AGAINST TIME REQUIRED USE ONE ROUTE ONLY FOR EACH ENTRY REGULAR PRESCRIPTION MONTH YEAR March2011 DOSE DATE STARTCHANGE 07/03/2011 DATE 03/07/2011 DRUGOTHER INSTRUCTIONSSIGNATUREPHARMACY ROUTE ORAL CO-AMOXICLAV125/31 SUSPENSIONA.Doctor INITIALS AD 69 5mls 14 5mls mls

London Specialty School of Paediatrics Principles of Prescribing Fluids Usual maintenance fluid in this trust is [TRUST FLUID] Children on IV fluids will need daily U&Es (change based on local trust guidelines) Ensure you prescribe: –Fluid type (concentration) –Volume (e.g. 500ml bag) –Rate (mls/hour) –Additives if required –?duration (some trusts)

London Specialty School of Paediatrics Calculating and Prescribing Maintenance Fluids This should be prescribed based on weight: –For every kg up to 10kg100mls/kg/day –For every kg between kg 50mls/kg/day –For every kg over 20kg 20mls/kg/day –This will be the maintenance fluid required over 24 hours –The total should therefore be divided by 24hrs to give a rate in mls/hr –Consider whether the child requires potassium

London Specialty School of Paediatrics Prescribing Fluid- Example 3: Prescribing Maintenance Fluid Abigail, a 10 year old child weighs 32 kg. She requires maintenance fluid over the next 24 hours. Please prescribe this. If unsure, use the BNFC: Click Here Working: 100mls/kg/day = 1000mls 50mls/kg/day = 500mls 20mls/kg/day= 240mls –24 hour requirement:= 1740mls= 72.5mls / hour (for 24 hours) DateInfusion FluidVolume Name of Drug to be infused Dose of Drug Added RouteInfusion rateSignature 14/3/11O.9%NACL/5%DEXTROSE500MLNIL-IV73ML/HRA.doctor

London Specialty School of Paediatrics Principles of Prescribing Fluids Calculating deficit in dehydration This is based on child’s weight and % dehydration Calculation for fluid deficit for %dehydration: –(%dehydration/100%) x weight (kg) x 1000ml/kg THIS can be simplified to –%dehydration x weight x 10= total fluid deficit (mls) This should be replaced over hours This represents the extra fluid that is needed so should be added to total maintenance requirements

London Specialty School of Paediatrics Prescribing Fluid- Example 4: Prescribing Rehydration fluid Chloe, a 10 year old child weighs 32 kg (the same as her friend Abigail in example 3) She is clinically 5% dehydrated due to gastroenteritis. Prescribe fluid to rehydrate her over the next 24 hours. Please prescribe this. Working for maintenance: 100mls/kg/day = 1000mls 50mls/kg/day = 500mls 20mls/kg/day= 240mls –24 hour maintenance requirement:= 1740mls Additional fluid required: –(%dehydration/100%) x weight (kg) x 1000ml/kg –(5/100) x 32kg x 1000ml/kg = 1600mls Total fluid required in 24 hours= 1740mls mls = 3340mls DateInfusion FluidVolume Name of Drug to be infused Dose of Drug Added RouteInfusion rateSignature 14/3/11O.9%NACL/5%DEXTROSE500ML NIL_ IV139ML/HR A.doctor

London Specialty School of Paediatrics Principles of Prescribing Fluids In neonates Requirements depend on gestation, age (day of life) and weight The usual neonatal fluid is 10% dextrose Fluids may or may not require additives –Usual sodium requirements are 2-6 mmols / kg / day –Usual potassium requirements are 1-3 mmols / kg / day –These may change depending on the clinical condition of the patient

London Specialty School of Paediatrics Prescribing Fluids- Example 5: Prescribing fluids for neonates Baby Alfie is born at 37/40 He weighs 2.8kg He was born four hours ago Prescribe fluid for Alfie for the next 24 hours (day 1 of life) Workings: –In our trust, we prescribe 60mls/kg/day on day 1 of life with no additives Alfie will need 60mls/kg x 2.8kg = 168mls/24 hrs 7mls/hour DateInfusion FluidVolume Name of Drug to be infused Dose of Drug Added RouteInfusion rateSignature 14/3/1110% DEXTROSE500MLNIL_IV7ML/HRA.doctor

London Specialty School of Paediatrics Prescribing Fluids- Example 6: Prescribing additives for neonates Baby Begum is born at 35 weeks gestation, weighing 2.5kg She is 3 days old and you have been asked to prescribe fluid at 120ml/kg/day with 2mmol/kg/day of potassium and 3mmol/kg/day of sodium. Workings: –Fluid: 2.5kg x 120mls/kg/day = 300mls/day = 12.5mls/hour –Sodium: 2.5kg x 3mmol/kg/day = 7.5 mmol/day –Potassium: 2.5kg x 2mmol/kg/day = 5 mmol/day –Therefore 300mls of 10% Dextrose mmol of Sodium + 5 mmol of potassium is the daily requirement –Fluids are administered in standard 500ml bags so the equivalent doses need to be calculated to give the correct concentration of fluid. –Sodium in 500ml bag= (500/300) x 7.5mmol= 12.5mmol –Potassium in 500ml bag= (500/300) x 5mmol = 8.3mmol = 8mmol DateInfusion FluidVolumeName of Drug to be infused Dose of Drug Added RouteInfusion rateSignature 14/3/11 10% DEXTROSE 500MLSODIUM CHLORIDE POTASSIUM CHLORIDE 12.5MMOL 8.3MMOL IV12.5 ML/HR A.doctor

London Specialty School of Paediatrics Local Drug Chart [spend this time going over your drug chart]

London Specialty School of Paediatrics Trust guidelines & policies [Outline any specific trust guidelines & policies here]

London Specialty School of Paediatrics Questions?

London Specialty School of Paediatrics Paediatric Prescribing Summary Don’t forget: –Age –Weight –Show your calculations initially –Always use local guidelines or BNFC to check doses –Prescribe in dose rather than mls whenever possible –If you are ever unsure, always ask for help from a senior colleague or pharmacist