Antiseptic Stewardship for Skin Antiseptics

Alcohol-based skin antiseptics are based on ethanol, propan-2-ol or propan-1-ol. Some products contain additional non-volatile biocidal active substances such as chlorhexidine digluconate, benzalkonium chloride, hydrogen peroxide, povidone iodine or octenidine dihydrochloride. Currently, only chlorhexidine digluconate has a proven health benefit (prevention of catheter-associated bloodstream infections and probably also surgical site infections). Octenidine dihydrochloride and povidone iodine may also have a health benefit, but the evidence is weak. There is no health benefit for the addition of benzalkonium chloride or hydrogen peroxide. Chlorhexidine digluconate and benzalkonium chloride can cause a strong and stable increase in MIC with many mainly Gram-negative species. Cross-tolerance between benzalkonium chloride and chlorhexidine digluconate is common. Horizontal gene transfer can be induced by chlorhexidine digluconate in E. coli. The expression of antibiotic resistance genes can be increased by chlorhexidine digluconate in vanA E. faecium. And efflux pump genes can be upregulated by benzalkonium chloride, chlorhexidine digluconate, octenidine dihydrochloride and ethanol in some species. The overall balance justifies the use of chlorhexidine digluconate in alcohol, despite a number of risks. It may also be favourable for octenidine dihydrochloride and povidone iodine in alcohol (there is little evidence of a health benefit). Alcohol-based skin antiseptics with benzalkonium chloride should be replaced, given the magnitude of the risks and the lack of a health benefit of benzalkonium chloride.