Omiganan Pentahydrochloride is a pentahydrochloride salt of omiganan, a synthetic cationic antimicrobial peptide with wide-spectrum activity against both gram-positive and gram-negative bacteria and fungi. Omiganan pentahydrochloride, an analog of indolicidin, acts by disrupting bacterial cytoplasmic membranes and has been tested in a topical gel for the prevention of catheter-related bloodstream infections. The activity of omiganan pentahydrochloride (formerly MBI 226; a synthetic cationic peptide) was assessed against 1,437 recent clinical bacterial isolates and 214 recent clinical yeast isolates.