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Prescribing for children
For detailed advice on medicines used for children,
consult
BNF for Children
Children, and particularly neonates, differ from adults in
their response to drugs.
Special
care is needed in the
neonatal
period (first 28 days of
life) and doses should
always be calculated with care.
At this age,
the risk of
toxicity is increased by reduced drug clearance and
differing target organ sensitivity.
Whenever possible,
intramuscular injections should be
avoided in children because they are painful.
Where possible,
medicines for children should be pre-
scribed within the terms of the marketing authorisation
(product licence). However, many children may require
medicines not specifically licensed for paediatric use.
Although medicines cannot
be promoted outside the
limits of the licence, the Medicines Act does not prohibit
the use of unlicensed medicines. It is recognised that the
informed use of
unlicensed medicines or
of
licensed
medicines for unlicensed applications (‘off-label’ use) is
often necessary in paediatric practice.
Adverse drug reactions in children
The reporting
of all suspected adverse drug reactions, no matter how
minor,
in children under 18 years is strongly encour-
aged through the Yellow Card Scheme (see p.
12) even
if
the
intensive
monitoring
symbol
(T)
has
been
removed.
This is because experience in children may
still be limited.
The identification and reporting of adverse reactions to
drugs in children is particularly important because:
.
the action of the drug and its pharmacokinetics in
children (especially in the very young)
may be
different from that in adults;
.
drugs are not extensively tested in children;
.
many drugs are not specifically licensed for use in
children and are used ‘off-label’;
.
suitable formulations may not be available to allow
precise dosing in children;
.
the nature and course of illnesses and adverse drug
reactions may differ between adults and children.
Prescription writing
Prescriptions should be written
according to the guidelines in Prescription Writing (p.
5)
Inclusion of
age is a legal
requirement
in the case of
prescription-only medicines for children under 12 years
of
age,
but
it
is
preferable to state the age for
all
prescriptions for children.
It
is
particularly important
to state the strengths of
capsules or
tablets.
Although liquid preparations are
particularly suitable
for
children,
they may contain
sugar which encourages dental
decay.
Sugar-free med-
icines are preferred for long-term treatment.
Many children are able to swallow tablets or capsules
and may prefer a solid dose form;
involving the child
and parents in choosing the formulation is helpful.
When a prescription for
a liquid oral
preparation is
written and the dose ordered is smaller than 5 mL an
oral
syringe will
be supplied (for
details,
see p.
2).
Parents should be advised not
to add any medicines
to the infant’s feed, since the drug may interact with the
milk or other liquid in it; moreover the ingested dosage
may be reduced if
the child does
not
drink all
the
contents.
Parents must be warned to keep all
medicines out
of
reach of children, see Safety in the Home,
p.
3.
Rare paediatric conditions
Information on substances such as
biotin
and
sodium
benzoate
used in rare metabolic conditions is included
in
BNF for
Children
;
further
information
can
be
obtained from:
Alder Hey Children’s Hospital
Drug Information Centre
Liverpool
L12 2AP
Tel:
(0151) 252 5381
Great Ormond Street Hospital for Children
Pharmacy
Great Ormond St
London WC1N 3JH
Tel:
(020) 7405 9200
Dosage in children
Children’s doses in the BNF are stated in the individual
drug entries as far as possible,
except where paediatric
use is not recommended, information is not available, or
there are special hazards.
Doses
are generally based on body-weight
(in kilo-
grams) or the following age ranges:
first month (neonate)
up to 1 year (infant)
1–5 years
6–12 years
Unless the age is specified,
the term ‘child’
in the BNF
includes persons aged 12 years and younger.
Dose calculation
Many children’s doses are standar-
dised by weight (and therefore require multiplying by
the body-weight
in kilograms to determine the child’s
dose);
occasionally,
the doses have been standardised
by body surface area (in m
2
). These methods should be
used rather than attempting to calculate a child’s dose
on the basis of doses used in adults.
For most drugs the adult maximum dose should not be
exceeded. For example if the dose is stated as 8 mg/kg
(max.
300 mg),
a child weighing 10 kg should receive
80 mg but a child weighing 40 kg should receive 300 mg
(rather than 320 mg).
Young children may require a higher dose per kilogram
than adults because of
their
higher
metabolic rates.
Other
problems need to be considered.
For example,
calculation by body-weight in the overweight child may
result
in much higher doses being administered than
necessary; in such cases, dose should be calculated from
BNF 61
Prescribing for children
15
Prescribing for children