T2iii: Outline the pharmacology of antiseptics and disinfectants
Definitions
Antiseptic = substance applied topically to prevent growth of micro-organisms
Not for use on inaminate objects bc does not have the same killing power of chemicals used for disinfection
Disinfectant = agent applied topically to inanimate object to destroy pathogens
Class
Alcohol
Antiseptic
Chlorhexidine
Antiseptic
Povidine Iodine
Antiseptic
Glutaraldehyde
Disinfectant
Presentation
Alcohol
70% Isopropyl Alcohol
Chlorhexidine
Aqueous or combined with alcohol
Povidine Iodine
Iodine combined with polymer (povidone) to enhance water solubility
Glutaraldehyde
Pugnent, colourless, oily liquid
MoA
Alcohol
Denatures proteins
Chlorhexidine
At physiological pH
Chlorehex salts dissociate
Release + charge
Cation binds -ve charge bac cell wall
Chlorhex denatures proteins & lipids of bac = lysis
Povidine Iodine
Povidone carries Iodine to pathogen
Iodine penetrates cell wall and membrane
Pore insertion = bactericidal
Glutaraldehyde
Associates w bacterial cell wall
Cross linking inhibits further bacterial cell fns
Antiviral
Alcohol
Poor viral
Chlorhexidine
Poor antiviral
Povidine Iodine
Good antiviral
Glutaraldehyde
Antibacterial
Alcohol
Broad spectrum
Chlorhexidine
G + > – > fungi
Povidine Iodine
Broad spectrum
G + > – > fungi > virus
Glutaraldehyde
Advantages
Alcohol
Broad spectrum Gram cover, fungi
Kills 90% skin bacteria in 2mins
Doesn’t need to dry for effect – evaporation limits its microbe activity
Chlorhexidine
Rapid onset, lasts 48hrs
Povidine Iodine
Can be used following 70% alcohol to keep recolonization down for 60mins
Area of application visible
Can be used w chlorhex allergy
Glutaraldehyde
Broad spectrum:
Bacteria, their spores, fungi, viruses, mycobacteria
Disadvantages
Alcohol
Flammable
Irritant to skin
Potential for allergy
Chlorhexidine
Requires 30sec scrub
Neurotoxic
Flammable
Cannot be used directly on mucosa
Povidine Iodine
Cannot be used if hyperthyroid
Glutaraldehyde
Irritant
Contact dermatitis
Pungent odour