klorhexidin

Klorhexidin, also known as chlorhexidine, is a synthetic cationic bisbiguanide used as an antiseptic and disinfectant. It is available in several salt forms, most commonly chlorhexidine digluconate. It has broad-spectrum antimicrobial activity against Gram-positive and many Gram-negative bacteria, as well as yeasts and some fungi. Its activity against spores and many non-enveloped viruses is limited. The antiseptic effect results from binding to negatively charged microbial surfaces and disrupting cell membranes, leading to leakage of cellular contents. A characteristic feature is substantivity: chlorhexidine can bind to skin and mucous membranes and release gradually over time, providing extended antimicrobial action.

Chlorhexidine is used in a variety of settings. In medicine, it is employed for preoperative skin preparation, wound cleansing, and routine hand antisepsis in healthcare facilities. In dentistry and oral care, chlorhexidine is widely used in mouthrinses, gels, and varnishes to reduce dental plaque and gingivitis. It is also used in some topical skin preparations and in impregnated catheters or dressings.

Common formulations include mouthrinses with about 0.12% chlorhexidine and topical solutions ranging from 0.5% to 4% depending on the indication. Safety considerations include possible transient alteration of taste, tooth staining with prolonged mouthwash use, mucosal irritation, and, rarely, severe allergic reactions. Chlorhexidine should not be ingested, and it can be inactivated by anionic substances; it is less effective in the presence of certain soaps or detergents.

Infection control guidelines emphasize appropriate use to minimize resistance and adverse effects. Chlorhexidine has a long history of clinical use and remains a widely used antiseptic in both medical and dental settings.