BNF for Children (BNFC) 2018-2019

Bowel colic and excessive respiratory secretionsHyoscine
hydrobromide p. 266 effectively reduces respiratory
secretions and is sedative (but occasionally causes
paradoxical agitation); it is given in asubcutaneousor
intravenous infusion. Glycopyrronium bromide p. 751 may
also be used.
Hyoscine butylbromide p. 62 is effective in bowel colic, is
less sedative than hyoscine hydrobromide, but is not always
adequate for the control of respiratory secretions; it is given
bysubcutaneous infusion(important:hyoscine butylbromide
p. 62 must not be confused withhyoscine hydrobromide,
above).

Confusion and restlessnessHaloperidol p. 245 has little
sedative effect. Levomepromazine p. 268 has a sedative
effect. Midazolam p. 223 is a sedative and an antiepileptic
that may be suitable for a very restless patient.

ConvulsionsIf a child has previously been receiving an
antiepileptic drugorhas a primary or secondary cerebral
tumouroris at risk of convulsion (e.g. owing to uraemia)
antiepileptic medication should not be stopped. Midazolam
is the benzodiazepine antiepileptic of choice forcontinuous
subcutaneous infusion.

Nausea and vomitingLevomepromazine p. 268 causes
sedation in about 50 % of patients. Haloperidol p. 245 has
little sedative effect.
Cyclizine p. 260 is particularly likely to precipitate if mixed
with diamorphine hydrochloride p. 277 or other drugs (see
underMixing and compatibility); it is given bysubcutaneous
infusion.

Pain controlDiamorphine hydrochloride p. 277 is the
preferred opioid since its high solubility permits a large dose
to be given in a small volume (see underMixing and
compatibility). The table shows approximate equivalent doses
of morphine p. 282 and diamorphine hydrochloride.

Mixing and compatibilityThe general principle that
injections should be given into separate sites (and should
not be mixed) does not apply to the use of syringe drivers in
palliative care. Provided that there is evidence of
compatibility, selected injections can be mixed in syringe
drivers. Not all types of medication can be used in a
subcutaneous infusion. In particular, chlorpromazine
hydrochloride p. 244 , prochlorperazine p. 268 , and diazepam
p. 220 arecontra-indicatedas they cause skin reactions at
the injection site; to a lesser extent cyclizine p. 260 and
levomepromazine p. 268 also sometimes cause local
irritation.
In theory injections dissolved in water for injections are
more likely to be associated with pain (possibly owing to
their hypotonicity). The use of physiological saline (sodium
chloride 0. 9 %p. 589 ) however increases the likelihood of
precipitation when more than one drug is used; moreover
subcutaneous infusion rates are so slow ( 0. 1 – 0. 3 mL/hour)
that pain is not usually a problem when water is used as a
diluent.

Compatibility with diamorphineDiamorphine can be given
bysubcutaneous infusionin a strength of up to 250 mg/mL;
up to a strength of 40 mg/mL eitherwater for injectionsor
physiological saline(sodium chloride 0. 9 %) is a suitable
diluent—above that strength onlywater for injectionsis used
(to avoid precipitation).
The following can be mixed withdiamorphine:

.Cyclizine, may precipitate at concentrations above

10 mg/mLorin the presence of sodium chloride 0. 9 %

oras the concentration of diamorphine relative to

cyclizine increases; mixtures of diamorphine and

cyclizine are also likely to precipitate after 24 hours.

.Dexamethasone, special care is needed to avoid

precipitation of dexamethasone when preparing it.

.Haloperidol, mixtures of haloperidol and

diamorphine are likely to precipitate after 24 hours if

haloperidol concentration is above 2 mg/mL.

.Hyoscine butylbromide

.Hyoscine hydrobromide

.Levomepromazine

.Metoclopramide, under some conditions infusions

containing metoclopramide become discoloured; such

solutions should be discarded.

.Midazolam

Subcutaneous infusion solution should be monitored

regularly both to check for precipitation (and discolouration)

and to ensure that the infusion is running at the correct rate.

Problems encountered with syringe driversThe following

are problems that may be encountered with syringe drivers

and the action that should be taken:

.if the subcutaneous infusion runstoo quicklycheck the

rate setting and the calculation;

.if the subcutaneous infusion runstoo slowlycheck the

start button, the battery, the syringe driver, the

cannula, and make sure that the injection site is not

inflamed;

.if there is aninjection site reactionmake sure that the

site does not need to be changed—firmness or swelling

at the site of injection is not in itself an indication for

change, but pain or obvious inflammation is.

Equivalent doses of morphine sulfate and

diamorphine hydrochloride given over 24 hours

These equivalences areapproximate onlyand should be

adjusted according to response

ORAL MORPHINE PARENTERAL

MORPHINE

PARENTERAL

DIAMORPHINE

Oral morphine

sulfate

over 24 hours

Subcutaneous

infusion of

morphine sulfate

over 24 hours

Subcutaneous

infusion of

diamorphine

hydrochloride

over 24 hours

30 mg 15 mg 10 mg

60 mg 30 mg 20 mg

90 mg 45 mg 30 mg

120 mg 60 mg 40 mg

180 mg 90 mg 60 mg

240 mg 120 mg 80 mg

360 mg 180 mg 120 mg

480 mg 240 mg 160 mg

600 mg 300 mg 200 mg

780 mg 390 mg 260 mg

960 mg 480 mg 320 mg

1200 mg 600 mg 400 mg

If breakthrough pain occurs give a subcutaneous injection

equivalent to one-tenth to one-sixth of the total 24 -hour

subcutaneous infusion dose. With an intermittent subcutaneous

injection absorption is smoother so that the risk of adverse effects

at peak absorption is avoided (an even better method is to use a

subcutaneous butterfly needle). To minimise the risk of infection no

individual subcutaneous infusion solution should be used for

longer than 24 hours.

BNFC 2018 – 2019 Prescribing in palliative care 23

Prescribing in palliative care