Antiseptic

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An antiseptic (Greek αντι, against, and σηπτικος, putrefactive) is a substance that prevents the growth and reproduction of various microorganisms (such as bacteria, fungi, protozoa, and viruses) on the external surfaces of the body. Some are true germicides, capable of destroying the bacteria, whilst others merely prevent or inhibit their growth. The objective of antiseptics is to reduce the possibility of sepsis, infection, or putrefaction by germs. Antibacterials have the same objective but only act against bacteria. Antibiotics perform a similar function, preventing the growth or reproduction of bacteria within the body. Disinfectants operate on nonliving objects such as medical instruments.

The widespread introduction of antiseptic surgical methods followed the publishing of the paper Antiseptic Principle of the Practice of Surgery in 1867 by Joseph Lister, inspired by Louis Pasteur's germ theory of putrefaction. Some of this work was preceded slightly by that of Dr. George H Tichenor and Ignaz Semmelweis.

For the growth of bacteria there must be a certain food supply, moisture, in most cases oxygen, and a certain minimum temperature (see bacteriology). These conditions have been specially studied and applied in connection with the preserving of food and in the ancient practice of embalming the dead, which is the earliest illustration of the systematic use of antiseptics.

In early inquiries a great point was made of the prevention of putrefaction, and work was done in the way of finding how much of an agent must be added to a given solution, in order that the bacteria accidentally present might not develop. But for various reasons this was an inexact method, and to-day an antiseptic is judged by its effects on pure cultures of definite pathogenic microbes, and on their vegetative and spore forms. Their standardization has been effected in many instances, and a water solution of phenol of a certain fixed strength is now taken as the standard with which other antiseptics are compared.

Some common antiseptics are:

  • Alcohol: Used to disinfect the skin before injections are given, often along with iodine.
  • Quaternary ammonium compounds (such as benzalkonium chloride): Used as a pre-operative skin disinfectant. Antiseptic towels are often impregnated with this chemical.
  • Boric acid: Used in suppositories to treat yeast infections of the vagina, in eyewashes, and as an antiviral to shorten the duration of cold sore attacks. Put into creams for burns. Also common in trace amounts in eye contact solution. Though it is popularly known as an antiseptic, it is in reality only a soothing fluid, and bacteria will flourish comfortably in contact with it.
  • Chlorhexidine Gluconate: Used as a skin antiseptic and to treat inflammation of the gums (gingivitis)
  • Hydrogen peroxide: Used as a 6% (20Vols) solution to clean and deodorise wounds and ulcers. More common 1% or 2% solutions of hydrogen peroxide have been used in household first aid for scrapes, etc. However, even this less potent form is no longer recommended for typical wound care as the strong oxidization causes scar formation and increases healing time. Gentle washing with mild soap and water or rinsing a scrape with sterile saline is a better practice.
  • Iodine: Usually used in an alcoholic solution or as Lugol's iodine solution as a pre- and post-operative antiseptic. No longer recommended to disinfect minor wounds because it induces scar tissue formation and increases healing time. Gentle washing with mild soap and water or rinsing a scrape with sterile saline is a better practice.
  • Mercurochrome: Not recognized as safe and effective by the U.S. FDA due to concerns about its mercury content.
  • Phenol (carbolic acid) compounds. Phenol is germicidal in strong solution, inhibitory in weaker ones. Used as a "scrub" for pre-operative hand cleansing. Used in the form of a powder as an antiseptic baby powder, where it is dusted onto the belly button as it heals. Also used in mouthwashes and throat lozenges, where it has a painkilling effect as well as an antiseptic one. Example: TCP
  • Sodium chloride: Used as a general cleanser. Also used as an antiseptic mouthwash.
  • Sodium hypochlorite

But every antiseptic, however good, is more or less toxic and irritating to a wounded surface. Hence it is that the "antiseptic" method has been replaced in the surgery of to-day by the "aseptic" method, which relies on keeping free from the invasion of bacteria rather than destroying them when present.

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References

fr:Antiseptique nl:Antisepsis pl:Antyseptyka pt:Antiséptico fi:Antiseptiikka uk:Антисептик

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