Today I have asked several people their views and they are perplexed at the question. It is simple, but it questions routine practice.
In one hand I have a bottle of chlorhexidine 0.5% in alcohol that says – to be used undiluted – you can look on the MHRA website to verify this.
In the other hand I have a bottle of red-staining solution that says – mix with chlorhexidine 0.5% in spirit. You can’t look on the MHRA website for this as it is not a licensed product as it does not make in its own right a medicinal or therapeutic claim. It simply stains the skin so you know where the medicinal product has been applied.
So should I mix them?
- Well the medicinal product says no – it is not within its license – so this would be an ‘off-label’ use
- And the MHRA doesn’t know that this happens, have never dealt with a licence variation and has never looked at safety and efficacy – cos I asked them
- So I am adding a highly concentrated solution of an anionic dye to a cationic antiseptic – does that sound right?
- A text book published in 2001 says that precipitation of chlorhexidine is likely at the concentrations necessary for skin delineation – and if I add it to the 200ml unlicensed 2% solution I go way above this
- An Australian paper comparing a licensed 2% product (stable dye included) with an unlicensed 2% product with this dye added suggests that there is a 3.4 increased risk of positive bacterial swabs and they don’t sound surprised – you should read it
- A poster at ECCMID from a team in the West Midlands compared licensed 2% to licensed 0.5% with the added dye and showed a clear difference in colony forming units and surgical site infections in an early interim analysis – the manuscript is submitted for publication. What drove their results – was it the lower concentration of chlorhexidine or that they might have precipitated it before application – who knows. What’s your bet here a 10% difference in surgical infection rates – higher or lower?
So here is the million dollar question – the little bottle of dye which has no regulatory status within the UK says you can, but everything in your head says hold on a minute.
What’s the majority decision in the NHS today – the double whammy – have an unlicensed product and add an unlicensed dye and don’t tell any patient what you have done – brilliant!