Download Paediatric Prescribing and Common Medications

Paediatric Prescribing
and Common
Medications
Diana Mowbray
Paediatric Clinical Pharmacist
Rotherham NHS Foundation Trust
Things to Consider When
Prescribing
• Child’s age and weight (Kg) / surface
area
• Allergy status
• Obesity / underweight
• Immune status
• How to get the drug into the body
Common Drugs
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Antipyretics
Pain killers
Antibiotics
Inhalers
Anti-epileptics
Anti-reflux medications
Fluids
Antipyretics
• Paracetamol
– 15mg/Kg 4hrly
• Ibuprofen
–
–
–
–
–
–
–
1-3/12
3/12 – 1yr
1-4yrs
4-7yrs
7-10yrs
10-12yrs
>12yrs
5mg/Kg TDS/QDS
50mg TDS/QDS
100mg TDS
150mg TDS
200mg TDS
300mg TDS
up to 400mg TDS/QDS
Oral Pain Killers
• Paracetamol
– Can go up to 20mg/Kg in > 1/12
– Max 90mg/Kg/day
– Can use a loading dose
• Ibuprofen
– As for antipyretics (max 30mg/Kg/day)
• Diclofenac
– Up to 1mg/Kg (max 50mg) TDS
Oral Pain Killers contd
• Codeine
– 0-12yrs
0.5-1mg/Kg every 4-6hrs
– > 12yrs
30-60mg every 4-6hrs
– Max 240mg daily
• Morphine
– 1-12/12
– 1-2yrs
– 2-12yrs
– >12yrs
80-200micrograms/Kg 4hrly
200-400micrograms Kg 4hrly
200-500micrograms/Kg 4hrly
max 20mg
5-20mg 4hrly
Antibiotics
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Penicillins
Cephalosporins
Macrolides
Aminoglycosides
Trimethoprim
Metronidazole
eg amoxicillin
eg cefotaxime
eg erythromycin
eg gentamicin
Inhalers
• Ipratropium bromide
– Can be useful in young babies for wheeze
• Salbutamol
– Useful in all ages for wheeze – variable
response in young babies
• Beclometasone
– Useful at step 2 upwards of the asthma
management guidelines
Anti-epileptics
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Carbamazepine
Sodium valproate
Phenytoin
Phenobarbitone
Midazolam
Clobazam
Diazepam
Anti-reflux medications
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Gaviscon infant sachets
Ranitidine
Domperidone
Omeprazole / Lansoprazole
Fluids
• Sodium chloride 0.45% with
Dextrose 5% - basic children’s fluid
• Dextrose 10% - basic neonatal fluid
• May be with or without potassium
chloride dependent on clinical
situation
Calculations
• Always best calculated against
weight / surface area where possible
• NSF for children recommends all
calculations should be documented in
patient’s notes
Anti-reflux medications
• A 5 week old term baby (4.13Kg) presents
with GORD. They have been treated with
Gaviscon infant sachets at home. The
child is still vomiting and not gaining
weight.
• You are asked to prescribe oral Ranitidine
and Domperidone
• What doses would you prescribe?
Anti-reflux medications
• Ranitidine – 1mg/Kg TDS
– Prescribe as 4.1mg or 4mg TDS
• Domperidone – 200400microgram/Kg 3-4 times a day
– Prescribe as 830-1650micrograms 3-4
times a day (0.83-1.65mg)
Anti-reflux medications
• Ranitidine comes as 75mg/5ml solution
– Calculate the volume required
– 0.27ml
• Domperidone comes as 1mg/ml suspension
– Calculate the volume required
– 0.83-1.65ml
Anti-epileptics
• A 7 yr old (21.7Kg) is admitted with
generalised seizures and needs to be
started on sodium valproate 200mg/5ml
• What dose would you prescribe initially
and what dose would you anticipate the
patient being maintained on?
• What volumes of medication will this mean
needs drawing up?
Sodium Valproate
• Initiate on 5-7.5mg/Kg BD
– 108.5-162.75mg BD
– Ideally prescribe 110-165mg BD
– 2.7-4.1ml BD
• Maintenance is 12.5-15mg/Kg BD
– 272-324mg BD
– 6.6-8.1ml BD
Lamotrigine
• A 3yr old (14.5Kg) known epileptic on
sodium valproate 3.8ml BD for 8
months is admitted with uncontrolled
seizures.
• You are asked to prescribe
Lamotrigine in addition
• What dose will you prescribe?
Lamotrigine
• Lamotrigine interacts with sodium
valproate (inhibits hepatic catabolism) and
so a lower dose is required than would be
if it was used with any other anti-epileptic
• Initial dose: 150microgram/Kg OD for 14
days, increasing gradually to a usual
maintenance of 1-5mg/Kg in 1-2 divided
doses (max 100mg)
• Calculate the doses required
Lamotrigine
• Initial dose is 2.2mg (2.175mg)
• This can be achieved by dissolving a
5mg tablet in 5ml water and giving
2.2ml
• Maintenance is 14.5-72.5mg/day
Other problem
• This child is also on a low dose of sodium
valproate for it’s weight.
• 3.8ml = 152mg = 10.5mg/Kg/dose
• Usual maintenance is 12.5-15mg/Kg/dose
• This is probably due to weight increase in
the last 8 months and should be adjusted
accordingly (perhaps before considering an
additional drug!)
Prescribing problems
• A patient arrives with the following list of
medication from mum (who has left the drugs at
home). Which ones would you be confident to
prescribe?
• Baclofen 20ml TDS
• Glycopyrollate 4ml QDS
• Clonazepam 3.5ml BD
• Sodium Valproate 10ml BD
• Levetiracetam 3ml BD
• Alimemazine 7.5ml ON
Prescribing Problems
• Baclofen only comes as 5mg/5ml
• Glycopyrollate is only available as a
“special”
• Clonazepam is only available as a “special”
• Sodium valproate only comes as
200mg/5ml
• Levetiracetam only comes as 100mg/ml
• Alimemazine is available in 2 strengths
Neonatal infusions
• A 760g neonate requires a dopamine
infusion to run at
7.5microgram/Kg/minute
• The infusion is prepared as 30mg
dopamine in 50ml of 10% dextrose
• What rate should the prescription
state for the pump to run at?
Neonatal infusions
• 0.76Kg x 7.5micrograms/Kg/min =
5.7micrograms/min
• 5.7micrograms/min x 60mins =
342micrograms/hour
• 30mg dopamine in 50ml contains 30 x 1000
/ 50ml = 600micrograms/ml
• The infusion needs to run at 342 / 600 =
0.57ml/hour
Common problems
• Decimal points may not be clear
– Trailing zeros eg 2.0 may be mistaken for 20
– Missing zeros eg .5 may be mistaken for 5
• Use of abbreviations to be avoided
• Concentration errors when only a volume is
prescribed
• Frequencies / times of administration not
prescribed on kardex = drugs not given
Common problems
• Not reading all the information in
BNFC to find an appropriate dose
– Mixing up of routes and doses
– Mixing up of reason for giving and doses
– Using correct age range (especially in
neonatal period) for doses and
frequencies
Quick Quiz
• How many mg of adrenaline in 1ml of
– 1 in 1000?
– 1 in 10,000?
• How many mmol of sodium in 500ml of
0.45% sodium chloride with 5% glucose?
• A 10Kg child requires 0.2mmol/Kg
(50mg/Kg) magnesium sulphate. How much
of a 50% solution do you need?
Answers
• 1g in 1000ml = 1mg/ml
1g in 10,000ml = 0.1mg (100microgram) /ml
• 0.9% sodium chloride contains 150mmol
Na/L = 75mmol in 500ml = 37.5mmol in
500ml of 0.45%
• 10Kg x 50mg/Kg = 500mg.
A
50% solution contains 50g/100ml =
50,000mg/100ml = 500mg/ml
Questions
?