Chlorhexidine, antiseptic/disinfectant

Following disinfection of a drain insertion site with chlorhexidine digluconate 2% solution, a 43-year-old man had severe anaphylaxis, manifest as dyspnea, shock, and ST segment elevation (46). In the past he had had two episodes of contact dermatitis with chlorhexidine antiseptics. 

As is apparent from the above information, there is no ideal disinfectant, antiseptic or preservative. All chemical agents have their limitations either in terms of their antimicrobial activity, resistance to organic matter, stability, incompatibility, irritancy, toxicity or corrosivity. To overcome the limitations of an individual agent, formulations consisting of combinations of agents are available. For example, ethanol has been combined with chlorhexidine and iodine to produce more active preparations. The combination of chlorhexidine and cetrimide is also considered to improve activity. QACs and phenols have been combined with glutaraldehyde so that the same effect can be achieved with lower, less irritant concentrations of glutaraldehyde. Some... 

Triclosan cannot only be applied as an emulsion, but it also has demonstrated antibacterial and antiinflammatory efficacy in eczema therapy when used as an antiseptic wash.28,30 Likewise, 10% povidone-iodine solution as a disinfectant showed excellent antibacterial activity together with improvement of clinical severity.79 As a 1% solution, chlorhexidine digluconate has shown superior effectiveness to triclosan in vitro, but may be only suitable for therapeutic use in intertriginous areas or as part of wet wrap dressings in the treatment of AD when used as an alcoholic solution.26,80... 

The need of skin disinfectants before injection is controversial.110 It is generally thought that the use of antiseptics may be ineffective and unnecessary.111112 Aseptic conditions are required for the use of catheters to minimize the infection. Povidone iodine and chlorhexidine are commonly used for the catheters. 

For skin disinfection, chlorhexidine has been formulated as a 0.5% w/v solution in 70% v/v ethanol and, in conjunction with detergents, as a 4% w/v surgical scrub. Chlorhexidine salts may also be used in topical antiseptic creams, mouthwashes, dental gels, and in urology for catheter sterilization and bladder irrigation. 

Preservatives and disinfectants. Many preservatives and disinfectants can be metabolized by a wide variety of Gram-negative bacteria, although most commonly at concentrations below their effective use levels. Growth of pseudomonads in stock solutions of quaternary ammonium antiseptics and chlorhexidine has resulted in infection of patients. Pseudomonas spp. have metabolized 4-hydroxy-benzoate ester preservatives contained in eye-drops and caused serious eye infections, and have also metabolized the preservatives in oral suspensions and solutions. In selecting suitable preservatives for formulation, a detailed knowledge of the properties of such agents, their susceptibility to contamination and limitations clearly provides invaluable information. 

Dentures should be removed and disinfected overnight using an antiseptic solution, e.g., chlorhexidine 0.12-0.2%. Disinfect oral tissues in addition to dental prosthesis. 

Chlorhexidine is a very effective antiseptic drug used in disinfectant soaps. Hexachlorophene, a twin drug of... 

SF Bloomfield. Chlorhexidine and iodine formulations. In JM Ascenzi, ed. Handbook of Disinfectants and Antiseptics. New York Marcel Dekker, 1996, pp. 133-158. 

Chlorhexidine is mainly used as an active ingredient in disinfectants, deodorants and antiseptics and as a preservative in cosmetics and pharmaceuticals. The EC positive list of preservatives permitted for use in cosmetics mentions Chlorhexidine and its salts with a maximum authorized concentration of 0-3%. Formulating and using the active ingredient one has to remember its cationic nature which causes reduction of activity in the presence of organic matter, e.g. blood, serum, soaps and other anionic compounds. Another cause of activity loss is based on the very low water-solubility of certain Chlorhexidine salts borate, citrate, carbonate, bicarbonate, chloride or phosphate salts precipitate in systems containing such anions. 

Endocrine Hypothyroidism and altered metabolism of thyroid hormones have been reported as adverse events in neonates and children, resulting from the use of antiseptics containing povidone-iodine [SED-15, 1896 SEDA-30, 279 SEDA-31, 411 SEDA-32, 440]. Because of concerns about possible iodine excess, chlorhexidine-based antiseptics have replaced povidone-iodine in some clinical settings. However, this may not be advantageous for infants and children who are receiving total parenteral nutrition (TPN) as iodine is not routinely added to TPN solutions. Previously, iodine deficiency was considered unlikely in patients receiving TPN, because of adsorption from iodine-containing skin disinfectants and other adventitious sources [67 68 ]. 

Quats are used as antiseptics in hospitals, where infection with pathogenic Staphylococci is a major problem [6]. For general skin disinfection, they are not recommended to be used alone because the organisms can be trapped between the surface of the skin and the inactive side of the molecular film [6]. They can be used in combination with other disinfectant molecules, such as chlorhexidine, for wound cleansing. Human toxicity is very low, although skin irritancy and sensitization have been occasionally reported. 

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