Download - Disinfectants Antiseptics
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Gabor Pozsgai MD.
Faculty of Medicine University of Pcs
2012
Inhibition of pathogen cell division
Elimination of pathogens
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Antimicrobial drugs
chemoterapeutics
may be given systemically
Disinfectants and antiseptics
cannot be used systemically
Urinary antiseptics are given systemically, butexert their action locally in the urinary tract
Antiseptics
applied topically to mucous membranes or skin
Disinfectants toxic, only for non sterilizable instruments and
objects
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Phenol coefficient
effect of compounds is compared to that of 5%
phenol
The more concentrated the solution the less
time is needed for it to exert its effect
Bacteriostatic/bactericidal
Sporocidal
Virucidal
Fungicidal
Parasiticidal
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Alcohols and glycols
Aldehydes
Phenols and derivatives
Acid derivatives
Halogens and halogen containing compounds
Oxidizing agents
Metals
Surface active detergents
Other compounds
Aliphatic alcohols
ethanol, isopropanol
antimicrobial activity increases with number of
carbon atoms
70% solution is the most active
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Aliphatic alcohols
do not kill parasites and bacterial spores
solutions have to be filtered through 0.22 m
pores
hydrogen peroxyde shlould be added
may be used to the skin
aerosol can be used to clean ventilators
mostly in combinations
Glycols
triethylene glycol
fumes are used to sterilize air
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Widest spectrum
bactericidal, sporocidal, virucidal, fungicidal
React with amino moieties of proteins
proteins are precipitated
damage tissues
mostly applied to objects
Formaldehyde
gaseous
formalin
saturated solution containing 34-38%
10% solution may be used to mucous membranes
explosive when mixed with sodium hypochlorite
often combined with anionic detergents
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Formaldehyde
the gas is used to sterilize rooms
solid polymer is used
releases formaldehyde if treated with steam
may be explosive if too concentrated
Methenamine
urinary antiseptic
releases formaldehyde in acidic urine
often combined with mandelic acid
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Glutaraldehyde
used to sterilize instruments
24.5% glutaraldehyde in 70% isopropanol at
pH7.5-8.5
very toxic to tissues
have to be cleaned from instruments
sodium bisulfite or sterile water
can be combined with anionic detergents
Phenol
now obsolete
at least 1-2% solution is needed
5% is toxic and precipitates proteins
gets into the CNS and damages plasma
membranes
excitatory symptoms, hypothermia, fainting
only used for objects and discharges
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Cresol poorly soluble in water
mixed with anionic detergents
bactericidal, parasiticidal
more active at high temperatures
Amylmetacresol
Chlorcresol
Thymol
Hexylresorcinol
urinary antiseptic
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Hexachlorophene
bacteriostatic and fungistatic
surgical hand antiseptic
were used for newborns
may be absorbed and damages the CNS
carbanilide and salicylanilide derivatives are used
instead
these cause rashes and photosensitivity
Chlorhexidine
not effective against Pseudomonas and Serratia
used to the skin throat and wounds
4% chlorhexidine gluconate
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Boric acid
5% solution or powder
binds to pyridoxine
sodium tetraborate in glycerol is used for oral
thrush of infants
boric acid in vaseline
may be used for vaginal irrigation very toxic in children if absorbed
Benzoic acid
preservative in food and drugs
esters of paraoxybenzoic acid are more suitable
methyl, ethyl, propyl or benzyl esters
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Salicylic acid
used in dermatology
fungicidal and keratolytic
relieves itch and sweating
dissolved in alcohol, as dermal patch, ointment
and paste
Mandelic acid
urinary antiseptic
decreases pH of urine to 5.0
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Iodine
bactericidal, sporocidal, virucidal, fungicidal
low tissue toxicity
Tincture of iodine
alcoholic solution containing 5% iodine and 4%potassium iodide
potassium iodide inhibits formation of toxichypoiodides
degraded when exposed to light
the solution gets lighter
Lugol's iodine
5% iodine dissolved in potassium iodide antithyroid effect
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Povidone-iodine
water soluble iodine complex of
polyvinylpyrrolidone
surgical antiseptic
also used for wounds and vaginal irrigation
Povidone-iodine
causes local reddening and burning sensation in
the skin
liberates histamine from mast cells
alcoholic solutions may irritate mucousmembranes
iodine may cause allergy and anaphylaxis
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Chlorine
gaseous
used to sterilize water
hypochlorous acid is formed and disintegrates to
hydrochloric acid and oxygen
more active at higher temperatures
damages metals, plastics, rubber and textiles
precipitates on surface of large dirt crumbs
Hypochlorites
damage bacterial membranes
form chloramines with amino groups of proteins
bactericidal, sporocidal, virucidal
Bleaching powder
calcium hypochlirote
badly damages tissues
used for walls, lavatories, pools, water
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Sodium hypochlorite used for wounds with boric acid
explosive if mixed with formalin
Chloramine B benzene derivative
more stable, less toxic
chlorogen, halazone
Sodium dichloroisocyanuric acid pH should be set to 6.2-6.8
release corrosive chlorine gas at lower pH
Bactericidal, virucidal, fungicidal
Large quantities of organic materialcompromises effectivity
Corrosive
Hydrogen peroxide
catalase releases nascent oxygen
short lasting effect
inactivated by trace heavy metals
corrosive for metals
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Hydrogen peroxide
0.3-3% for contact lenses, throat, ears, eyes andwounds
if used in body cavities, resulting gases have to bedrained
10% solution is coagulant
30% is astringent
crystals formed with urea are sold in tablets forsolution
stabilized and combined with detergents is usedfor instruments
Peroxyacetic acid
instable
corrodes brass, iron and zinc
Potassium permanganate 0.1-0.5% solution
colours tissues
used for wounds
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Mercury reacts with thiol groups of proteins
inactivates enzymes and precipitates proteins
Inorganic compounds are obsolete damage host proteins, too
mercuric chloride (corrosive sublimate)
mercuric oxide mercuric cyanide
mercuric amidochloride
mercuric sulfide
Organic mercury compounds
less toxic
antifungal
spermicide
active against Trichomonas toxic effects may be treated with glutathione or
cysteine
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Phenylmercuric borate
0.02% for skin and mucous membranes
Thiomersal
ethylmercuric thiosalicylilate sodium
Merbromin
dibromhydroxymercuric fluorescein sodium
Silver
silver ions damage tissues and precipitate proteins
protein bound and colloidal silver is less toxic
Silver nitrate astringent and wound treatment
Silver acetate
1% eyedrop for newborns against gonorrhoea
now obsolete
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Clean surfaces and promote penetration ofantiseptics
Anionic detergents
sodium or potassium salts of fatty acids
alkaline when dissolved in water
irritate skin
no antiseptic effect
used in combination
inactivate cationic detergents
Cationic detergents
antiseptic properties
bactericidal/bacteriostatic, antifungal
increase permeability of plasma membranes
most important ones contain quaternary nitrogen inactivated by anionic detergents
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Cationic detergents
adsorbed to fibrous, porous materials
may be removed by such substances
form film layer on the skin
microbes may thrive under the film
can be used to clean instruments and objects
Benzalkonium chloride
Cetylpyridinium bromide
Non-ionic detergents no antiseptic activity
do not inactivate cationic detergents
used in combination
Zwitterionic detergents also called amphoteric detergents
positive and negative charge within the samemolecule
antiseptic effect
provide long lasting bacteriostatic and fungistaticeffect if dried on instrumets
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Azo dyes
Triphenylmethane dyes strong antiseptics
organic materials inhibit their action
Crystal violet hexamethyl pararosaniline chloride
for wounds against Gram positive bacteria
anthelmintic effect
Fuchsine rosaniline hydrochloride
Acridine dyes
Proflavine for gums and throat
mutagenic
Acriflavine developed by Ehrlich against African Trypanosomiasis
Methylene blue methylthioninium chloride
urinary antiseptic
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Sulfur
fungicidal and parasiticidal
Fatty acids
Undecylenic acid, propionic acid
antifungal activity
Cleaning of objects from living pathogens, bacterial sporesand viruses
Physical methods
Heat
Dry heat Incineration
Hot air oven for glassware
Pasteurization 30 min at 65C, then 5 min at 85C
Boiling textiles
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Moist heat
Autoclave 20 min at 121C on 107.8 kPa or 10 min at 134C on 205.9
kPa
saturated high pressure steam
chemical and biological indicators are used to checkeffectivity
Filtration heat sensitive fluids
0.22 mpores
Chemical methods
Gas sterilization
Ethylene oxide heat-sensitive instruments, plastics, optical instruments,
transfusion instruments alkilates thiol groups of proteins
flammable
mixed with carbon dioxide or fluorinated hydrocarbons
items should be wrapped prior to sterilization
traces of the substance should be removed
items are aired for days
chemical and biological indicators are used