Syringe drivers

A syringe driver is a battery-operated pump which administers drugs subcutaneouslyconsult a specialist for information on the pump used in your area and how to use it. Many of the drugs administered via the syringe driver are not licensed for subcutaneous use and the responsibility for their use lies with the prescriber

Indications

• severe nausea and/or vomiting
• dysphagia
• severe oral lesions
• non-absorption of oral medication
• unconscious or sedated patient

Diluent

• most drugs and drug combinations used in a syringe driver need to be made up to a certain number of millimetres or volume with a diluent
• “Either normal saline or WFI may be used as a diluent. Most drugs are able to be diluted with either diluent with the exceptions being cyclIzine which must be diluted with WFI and Levomepromazine which must be diluted with NS
• Both diluents. have advantages and disadvantages....”
  • water for injection
    • has few ions present and therefore is less likely to cause precipitation of drugs out of solution
    • BUT may be more irritant to subcutaneous tissue
  • normal saline
    • contains ions and so is more likely to cause precipitation of drugs
    • BUT may be more like interstitial fluid and therefore less irritant to subcutaneous tissue

Compatibility

• often several drugs are combined in one syringe
• little work has been done on the compatibility of drugs in syringe drivers (see chart)
• examination of the drugs in the syringe may reveal visual incompatibility, e.g. precipitation BUT non-visual chemical reactions may be occurring leading to the inactivation of one or more of the drugs or the production of potentially toxic compounds
• only combine drugs that are absolutely essential – if there is any doubt, consultation with a drug information pharmacist will guide practice
• avoid combining more than three drugs in one syringe
• consider the use of more than one syringe driver when more than three drugs need to be given via this route or if there are concerns about compatibility

The following drugs should never be given subcutaneously DIAZEPAM, PROCHLORPERAZINE, CHLORPROMAZINE