Category:Antiseptics

An antiseptic is a medicine applied to living tissue to kill or inhibit microorganisms on its surface, in contrast to a disinfectant (applied to inanimate surfaces) and to a systemic antibacterial (administered for systemic infection). The category covers the skin-preparation medicines used before surgical incision and venipuncture, the wound-care medicines used in the treatment of contaminated wounds and ulcers, the oral antiseptics used as mouthwashes and pre-procedural oral preparations, the urological irrigants used in catheterised patients, the vaginal antiseptics used before obstetric and gynaecological procedures, and the hand antisepsis medicines used in clinical practice as the foundational infection-control measure.

The clinical history of antiseptic practice was assembled in the second half of the nineteenth century. The Hungarian obstetrician Ignaz Semmelweis, working at the Vienna General Hospital in the 1840s, observed that puerperal-fever mortality in the medical-student-attended obstetric ward was approximately ten-fold that of the midwife-attended ward; the difference, he concluded after the death of a colleague from a finger pinprick during autopsy, was that the medical students came to deliveries directly from cadaver dissection and carried "cadaveric particles" on their hands. The 1847 introduction of chlorinated-lime hand-washing in the Vienna obstetric ward reduced the puerperal-fever mortality from approximately 18 percent to under 2 percent.^[1] Semmelweis's findings were rejected by his contemporaries; he was dismissed from his post, suffered a mental breakdown, was committed to an asylum, and died there in 1865, two weeks after admission, of sepsis from beating by the asylum guards.

The British surgeon Joseph Lister, working at the Glasgow Royal Infirmary in the 1860s and inspired by Pasteur's germ-theory work in fermentation, introduced carbolic acid (phenol) as a surgical antiseptic. His 1867 Lancet paper, "On a new method of treating compound fracture, abscess, etc., with observations on the conditions of suppuration", reported sustained reductions in surgical-wound infection and amputation-stump mortality with carbolic-acid spray and dressing.^[2] Lister's antiseptic technique was the foundational event of modern surgical practice; his name survives in Listerine (originally a surgical antiseptic, then a mouthwash) and in the bacterial genus Listeria (named for him by Pirie in 1940).

The pharmacopoeia of antiseptics has expanded along several mechanistic lines. The halogen-based antiseptics include molecular iodine (tincture of iodine, the original; Lugol's solution; the slow-release povidone-iodine Betadine, Purdue Frederick 1955) and the chlorine-based compounds (sodium hypochlorite as Dakin's solution, used since the First World War for contaminated wounds; the more recent stabilised hypochlorous-acid solutions). The biguanide chlorhexidine (ICI, 1954), originally developed as a malarial-prophylaxis candidate and then repurposed as an antiseptic, is the most widely used skin-preparation antiseptic in contemporary surgical practice; the alcohol-chlorhexidine combination (the 2% chlorhexidine gluconate in 70% isopropyl alcohol preparation) is the standard preoperative skin preparation. The cationic surfactants (benzalkonium chloride, cetrimide) are used in wound irrigation and as preservative agents in pharmaceutical preparations. The alcohols (60-90% isopropyl alcohol, ethanol) are the basis of the alcohol-based hand rubs that have become the standard for hand antisepsis in clinical practice (since the WHO 5 Moments for Hand Hygiene initiative of 2006). The peroxides (hydrogen peroxide 3%, the recent peracetic acid preparations for surgical instruments) provide oxidising antisepsis but have largely been replaced by other agents for wound antisepsis because of their tissue toxicity and impaired wound healing. The silver-based antiseptics (silver sulfadiazine for burns, the silver-impregnated wound dressings, the colloidal-silver preparations of dubious efficacy in the over-the-counter market) round out the contemporary pharmacopoeia.

The clinical use of antiseptics is foundational to perioperative practice. The contemporary skin-preparation standard (chlorhexidine-alcohol applied with friction, allowed to dry for 30-60 seconds before incision) reduces surgical-site infection compared to povidone-iodine in most randomised studies. The mucous-membrane preparations for procedures requiring antisepsis (povidone-iodine for vaginal preparation before caesarean section, oral antisepsis with chlorhexidine before dental procedures and intubation in the ICU, urethral antisepsis with povidone-iodine before urinary catheterisation) have specific niches. The wound-care antiseptics are used in selected indications (chronic ulcer cleansing with cadexomer iodine; topical mupirocin for Staphylococcus aureus decolonisation, the latter actually an antibacterial rather than an antiseptic), with the general principle that prolonged antiseptic use on healing wounds delays granulation and re-epithelialisation and should be limited to acute contamination control. The hand-hygiene antiseptics (the alcohol-based hand rubs at the 80-percent compliance benchmark in good hospital practice) are the single most cost-effective infection-prevention intervention in clinical care.

The boundary between antiseptic and disinfectant is operational rather than chemical. The same molecular agent (sodium hypochlorite, glutaraldehyde, peracetic acid, the chlorinated phenols) may be used at one concentration as a surface disinfectant and at lower concentration as a skin or mucosal antiseptic; the regulatory categorisation (FDA over-the-counter antiseptic monograph versus EPA disinfectant registration) reflects the use rather than the chemistry. The contemporary clinical interest is increasingly in anti-biofilm agents and in the recognition that established microbial biofilms on indwelling catheters, prosthetic joints, and chronic wounds resist conventional antiseptics and antibacterials by mechanism distinct from planktonic microbial sensitivity.

By chemistry:

• Halogen-based:
  • Iodine: tincture of iodine; Lugol's solution; povidone-iodine (Betadine; standard preoperative and wound antiseptic in many institutions)
  • Chlorine: sodium hypochlorite (Dakin's solution; concentrated 5% household bleach diluted for wound care); stabilised hypochlorous acid (Vashe, Microcyn)
• Biguanides:
  • Chlorhexidine gluconate (Hibiclens for skin; Peridex for oral; ChloraPrep with alcohol for preoperative skin; the standard contemporary surgical-site-preparation antiseptic in U.S. and U.K.)
  • Polyhexamethylene biguanide (PHMB; in wound-care dressings)
  • Alexidine (oral antiseptic, European)
• Cationic surfactants:
  • Benzalkonium chloride (BAC)
  • Cetrimide
  • Benzethonium chloride
• Alcohols (hand antisepsis; skin preparation):
  • Isopropyl alcohol 60-90%
  • Ethanol 60-90% (often with chlorhexidine 0.5-2%)
  • N-propanol
• Peroxides and other oxidising:
  • Hydrogen peroxide 3% (limited modern wound-care use; first-aid use)
  • Peracetic acid (instrument disinfection)
  • Potassium permanganate (older wound and skin use)
• Silver-based:
  • Silver sulfadiazine (Silvadene; burn wound care)
  • Silver nitrate (umbilical-cord care, granulation-tissue cautery)
  • Silver-impregnated dressings (Acticoat, Aquacel Ag)
• Phenolic:
  • Hexachlorophene (largely withdrawn after CNS toxicity in infants)
  • Triclosan (largely retired from consumer antiseptic use)
• Dyes:
  • Gentian violet (selected dermatologic and topical uses)
  • Eosin (mucous-membrane use in some traditions)

The boundary of this category is "medicine applied to living tissue to inhibit or kill microorganisms on its surface." The disinfectants applied to inanimate surfaces (surgical-instrument sterilisation, environmental decontamination) are not antiseptics in the strict definition and are listed under disinfectants when that page is built. The systemic antibacterials administered for established infection are not antiseptics; topical antibacterials used as skin or wound treatments rather than as preventive antisepsis (mupirocin, neomycin, bacitracin, retapamulin, ozenoxacin) sit at the boundary and are cross-listed under topical antibiotics. The vaccines and immunoglobulin preparations used for infection prevention are not antiseptics. The medicines used for MRSA decolonisation (chlorhexidine body washing with mupirocin nasal ointment) are cross-listed for that indication.

This category page is an encyclopedia article about its subject. The actual index of medicines belonging to the category is generated automatically by the wiki engine, from category-membership declarations on the individual medicine pages, and appears at the foot of the page below the references.