Chlorhexidine Equally Effective in Alcohol or Water

A new study shows no significant difference in efficacy between alcoholic and aqueous chlorhexidine for the prevention of surgical site infection (SSI) after minor skin excisions.

Researchers at James Cook University (JCU; Cairns, Australia), Paul Hopkins Medical Centre (Mackay, Australia), and other institutions conducted a prospective, multicenter, randomized controlled trial in four private general practices in Queensland (Australia) from October 2015 to August 2016. In all, 916 consecutive adult patients presenting for minor skin excisions were randomly assigned to undergo preoperative skin antisepsis with 0.5% chlorhexidine in 70% ethanol (454 patients) or 0.5% chlorhexidine aqueous solution (462 patients).

In the intention-to-treat analysis of 909 cases that were available at follow-up treatment, no significant differences were found in the incidence of SSI between patients in the alcoholic chlorhexidine arm (5.8%) and patients in the aqueous chlorhexidine arm (6.8%), indicating a relative risk of 0.85, with the number needed to treat to benefit being 100. Adverse reaction incidence was low, with no difference between groups. The study was published on August 8, 2017, in the Canadian Medical Association Journal (CMAJ).

“We thought alcoholic chlorhexidine might be a better antiseptic than a water-based solution, as alcohol is an antiseptic in its own right. But we felt it was important to confirm that it really was better,” said senior author Professor Clare Heal, PhD, MBChB, of JCU. “Although the infection rate was slightly lower with the alcohol-based solution than in the water-based solution, the difference was not significant, and it would require 100 patients to be treated with alcoholic solution to prevent one extra infection.”

Chlorhexidine is a disinfectant and antiseptic used for skin disinfection (of both patients and the hands of the healthcare providers), and to sterilize surgical instruments. The chlorhexidine salts dissociate and release a positively charged chlorhexidine cation molecule, which causes a bactericidal effect by binding to negatively charged bacterial cell walls. At low concentrations, a bacteriostatic effect occurs; at high concentrations, membrane disruption results in cell death. It can be applied topically as a gel, wash, or powder.

Related Links:
James Cook University
Paul Hopkins Medical Centre