1. Syringe Driver Drugs

2. Diamorphine strong opioid of choice in UK as highly soluble
problems with availability in last two to three years
equivalent dose conversion from oral morphine = 1/3 rd eg 60mg total daily oral morphine = 20mg sc diamorphine over 24hrs
can precipitate with cyclizine if diamorphine concentration higher than 20mg/ml, or if cyclizine higher than 10mg/ml. Avoid saline as diluent if using cyclizine

3. Morphine
being used more as diamorphine supplies not as readily available
needs larger volumes to dissolve than diamorphine (syringe may need to be bigger)
conversion from oral morphine is ½ ie 20mg total 24hr oral morphine = 10mg sc morphine over 24hrs
conversion from sc diamorphine = x 1.5 ie 10mg sc diamorphine = 15mg sc morphine
same compatibility with other drugs as for diamorphine

4. Typical doses of common SD drugs
Analgesics
diamorphine, morphine, oxycodone
convert from oral morphine dose
no ceiling dose
remember breakthrough dose is 1/6th of total daily dose

5. Typical doses of common SD drugs
Anti-emetics
cyclizine: mg over 24hrs
(remember not to use with metoclopramide)
metoclopramide: mg over 24hrs
(remember contraindicated in total bowel obstruction)
haloperidol: 2.5mg-10mg over 24hrs
levomepromazine: mg over 24hrs
(NB long half-life, useful as bd boluses)

6. Typical doses of common SD drugs
Anti-cholinergics (reducing secretions, bowel obstruction)
glycopyrronium: mcg over 24hrs with stat doses of 200mcg
(NB does not cross blood brain barrier so less sedating)
hyoscine butylbromide (buscopan): 60-80mg over 24hrs with 20mg stat doses
hyoscine hydrobromide: mcg over 24hrs with stat doses of 200mcg
(NB more sedating than butylbromide)

7. Typical doses of common SD drugs
Anxiolytics
midazolam: 10-60mg over 24hrs with 5-10mg stat doses
haloperidol: 10-30mg over 24hrs
levomepromazine: mg over 24hrs
(NB can be irritant at infusion site)

8. Common incompatibilities
diamorphine and cyclizine at high dose (concentration dependent)
cyclizine and buscopan (hyoscine butylbromide)
cyclizine and oxycodone at high dose (concentration dependent)
dexamethasone – many incompatibilities
tables of incompatibilities for 3+ drugs

9. Frequently asked questions
What diluent should be used in the driver to mix drugs?
saline (commonest, most physiological)
water for injection
5% dextrose in water
exceptions are:
cyclizine (precipitates)
high dose diamorphine (>40mg/ml)
in which case water should be used

10. When should the syringe driver be started when switching from an oral slow release medication?
start the SD at the same time as the usual next oral dose of medication would have been given
no need for any crossover period
make sure patient is written up for appropriate dose of breakthrough analgesia given subcutaneously

11. When should the driver be stopped if oral Rx is to be re-started?
stop the driver as soon as the first oral m/r dose of opioid is given
no crossover period as some immediate release effect from opioid
ensure correct dose of oral breakthough analgesia is written up

12. How do I switch to a SD from a transdermal fentanyl patch?
continue fentanyl patch and add SD
if more analgesia needed, increase via SD

13. When do I stop the SD when I swap to a fentanyl patch?
stop the driver 12 hours after the first patch has been applied