Dimethyl sulfoxide enhances effectiveness of skin antiseptics and reduces contamination rates of blood cultures.

Effective skin antisepsis is of central importance in the prevention of wound infections, colonization of medical devices, and nosocomial transmission of microorganisms. Current antiseptics have a suboptimal efficacy resulting in substantial infectious morbidity, mortality, and increased health care costs. Here, we introduce an in vitro method for antiseptic testing and a novel alcohol-based antiseptic containing 4 to 5% of the polar aprotic solvent dimethyl sulfoxide (DMSO). The DMSO-containing antiseptic resulted in a 1- to 2-log enhanced killing of Staphylococcus epidermidis and other microbes in vitro compared to the same antiseptic without DMSO. In a prospective clinical validation, blood culture contamination rates were reduced from 3.04% for 70% isopropanol-1% iodine (control antiseptic) to 1.04% for 70% isopropanol-1% iodine-5% DMSO (P < 0.01). Our results predict that improved skin antisepsis is possible using new formulations of antiseptics containing strongly polarized but nonionizing (polar aprotic) solvents.