I'm not sure what other's practices are, but this is what I have found to be useful and hopefully scientific:
When presented with a patient who has a possible antibiotic allergy, eg penicillin and requries a similar antibiotic eg a cephalosporin some people advocate a IV test dose before a full dose is given.
This would minimise the effects of an anaphylactiod reaction, which is dose-related, but not a true anaphylactic reaction which can be triggered by a minimal amount of antigen.
My practice has been to give a tiny bleb of antibiotic as an intradermal injection, essentially making it a skin test. If there is no weal or flare 10mm or larger after 20 minutes, then I feel confident giving the full dose IV.
The advantage of this is that the antigen is not given as a systemic dose and thereby triggering a systemic reaction. It remains localised causing a local reaction only, yet still giving the required information.
I realise that even very dilute skin tests can cause anaphylaxis, but this technique is still safer than giving an IV "test dose".
Thought? Comments?
Sounds like a good idea Gasman.
What is contempory practice? Do people still give test doses of IV antibiotics?
I understood that the AAGBI guidelines on anaphylaxis suggest that a test dose is a waste of time?
Any thoughts?
dear gasman,
you are absolutely right.atleast by doing this you avoid a major catastrophe.we in ranchi ,india also practice this.
we don't do the skin test but we give a very small amount IV and wait,if no advers reactions we give full dose.