Injection compatibility: Reducing risk

Last updated: Monday, July 13, 2015

Injectable medicines can be mixed in a variety of ways:

  • In the same bag of intravenous fluid.

  • In the same syringe, diluted, for a subcutaneous infusion.

  • In the same syringe, neat, for intramuscular injection.

  • In the same intravenous line, or giving set.

  • In the same venflon.


Avoiding the Need for Mixing

The easiest way to solve an incompatibility problem is to think about ways to avoid mixing. You can remember these with the acronym: NATO (Necessary? Alternative route? Timing? Other drugs?):

Necessary?
Can some non-essential drugs be stopped? Is there any unnecessary duplication (e.g. you should not need to mix co-amoxiclav and metronidazole because their antibacterial spectrums overlap).

Alternative Routes?
Can an alternative route be used to avoid IV administration? For example:

  • Insulin may be given subcutaneously instead of IV.
    Is the oral route an option?                         © Crown copyright 2017

  • Metronidazole can be given rectally instead of IV.

  • Cefuroxime can be given by IM injection instead of IV.

  • Fluconazole has excellent bioavailability orally compared to IV.

  • If the patient has an NG tube, many drugs are available as oral syrups or solutions.

  • Many drugs can be given by IV injection as well as by infusion. Since IV injections are quicker, this may avoid the need for mixing.

Timing?
Changing the timing of drug administration may avoid the need for mixing.

  • Can short IV infusions be given sequentially (i.e. one after the other) to avoid mixing? This can often be done with antibiotics. Remember to flush between each drug.

  • Can a less urgent continuous infusion (e.g. pantoprazole) be interrupted temporarily to allow administration of a short infusion of a second drug?

Other Drugs?
Can you choose a different medicine?        © Crown copyright 2017
Can a different drug be used to overcome a compatibility problem? For example:

  • An IV injection of teicoplanin instead of a long IV infusion of vancomycin.

  • Subcutaneous tinzaparin can be given instead of an IV heparin infusion to treat PE.

  • Sublingual lorazepam instead of IV midazolam or diazepam for anxiety.

  • Sublingual buprenorphine instead of a parenteral opioid for pain.

  • Buccal prochlorperazine instead of a parenteral antiemetic.