Injection compatibility: Information sources

Last updated: Monday, July 13, 2015

Trissel’s Handbook on Injectable Drugs (American Society of Health-System Pharmacists) is a good starting point if you are asked about mixing drugs. Remember that medicines will be listed under their US names and not all UK drugs are included. A key disadvantage is that the concentrations included in Trissel do not always represent what is used in clinical practice. This may mean you have to make a judgement about their relevance.

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If Trissel isn’t helpful then try the online Injectable Medicines Guide. Where compatibility data are given, it is more likely to include concentrations that are used in UK practice. This database will also tell you about the pH of injections.

SPCs are rarely helpful if you are asked about mixing drugs, but can help with you questions around the choice of diluent to use. Alternatively consider contacting the product manufacturers for any in-house data they may have.

For enquiries about mixing drugs in syringe drivers, especially in the palliative care context, Andrew Dickman’s The Syringe Driver is an excellent resource (Oxford University Press).

Be careful about conducting a general internet search on this subject. If you do, you may like to look at our brief guide to evaluating websites about medicines.

Presenting your answer 

Once you’ve asked sufficient questions, gathered the information required and assessed it, you’ll need to provide an answer. As a reminder, we offer some general guidance on answering clinical problems. You might like to refresh your memory if you’ve not looked at this recently.