Syringe Driver Drugs

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

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

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

Typical doses of common SD drugs Anti-emetics cyclizine: 100-150mg over 24hrs (remember not to use with metoclopramide) metoclopramide: 30-120mg over 24hrs (remember contraindicated in total bowel obstruction) haloperidol: 2.5mg-10mg over 24hrs levomepromazine: 6.25-25mg over 24hrs (NB long half-life, useful as bd boluses)

Typical doses of common SD drugs Anti-cholinergics (reducing secretions, bowel obstruction) glycopyrronium: 600-1200mcg 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: 600-2400mcg over 24hrs with stat doses of 200mcg (NB more sedating than butylbromide)

Typical doses of common SD drugs Anxiolytics midazolam: 10-60mg over 24hrs with 5-10mg stat doses haloperidol: 10-30mg over 24hrs levomepromazine: 25-200mg over 24hrs (NB can be irritant at infusion site)

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

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

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

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

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

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