Antiseptics (Dr. Arhin) PDF

# Antiseptics - Agents (germicides) that inhibit the growth of microorganisms on the skin. - Destroy the growth of pathogenic vegetative bacteria (not spores) on skin or animate living surfaces. - Used to prevent infections. - Treat wounds, cuts, and skin conditions. - Different types with diverse...

# Antiseptics - Agents (germicides) that inhibit the growth of microorganisms on the skin. - Destroy the growth of pathogenic vegetative bacteria (not spores) on skin or animate living surfaces. - Used to prevent infections. - Treat wounds, cuts, and skin conditions. - Different types with diverse uses. ## Clinical Applications - **Wound Care:** Antiseptics like chlorhexidine and povidone-iodine are applied to prevent infection in cuts, burns, and surgical wounds. - **Acne Treatment:** Benzoyl peroxide and chlorhexidine help in reducing bacterial load on the skin. - **Pre-Surgical Skin Preparation:** Alcohol-based solutions and chlorhexidine are commonly used to reduce bacterial load before surgery. - **Dermatitis and Eczema:** Antiseptics can prevent secondary infections in damaged skin from scratching. ## Classification ### Phenol Derivatives: - Phenol, cresol, hexachlorophene, chlorhexylenol (Dettol) ### Oxidizing Agents: - Hydrogen peroxide ### Halogens: - Iodine, chlorine, chlorophores ### Biguanides: - Chlorhexidine ### Quaternary Ammonium: - Cetrimide ### Alcohols: - Ethanol, isopropanol ### Aldehyde: - Formaldehyde ### Acids: - Acetic Acid, boric acid - Metallic salt: Mercuric compounds, silver & zinc salts ### Dyes - Gentian violet, acriflavine ## Phenol Derivatives ### Phenol (Carbolic Acid) - Earliest used (reference standard) - Protoplasmic poison, - injures tissues & cells at high concentration - causes skin burn - To disinfect urine, feces, pus, burns - For Gram + and Gram -ve bacteria, fungi, viruses - Extremely irritating, corrosive - **MOA:** Denaturation of bacterial proteins and inactivate enzymes essential for bacterial growth. - Disruption of the cell membrane ## Cresol (Lysol) - Methyl derivative of phenol, less damaging to tissues than phenol. - 3-10 times more active. - Used for disinfection of excreta & for washing hands. - **MOA:** Disrupt cell membrane and causes permeability of the cell. ## Chloroxylenol (Dettol) - Does not coagulate proteins. - Non corrosive, non irritating to skin. - Commercial 4.8% solution used for surgical antisepsis. - Skin cream and soap. 0.8% - Mouth wash 1% - **MOA:** Disruption of cell membrane, leads to leakage of cellular contents. ## Hexachlorophene - Commonly incorporated in soap. - Effectively only against Gram +ve. - Slow but persistent action. - **MOA:** Integrates into the lipid bilayer of bacterial cell membranes and causes a disruption in the membrane's structure and increases its permeability. ## Oxidizing Agents - **Potassium permanganate** - Purple crystals, highly water soluble. - **MOA:** Liberates oxygen which oxidizes bacterial protoplasm. - Used for gargling, irrigating wounds, urethra (condy's lotion diluted solution of 1.4000 to 1.10,000) - High concentrations cause burns - It is also used to disinfect water in ponds. ## Hydrogen Peroxide - Liberates nascent oxygen which oxidizes necrotic matter & bacteria - Helps in loosening and removing slough, ear wax, etc. ## Benzoyl Peroxide - Widely used drug for acne. - Liberates O2 in presence of water which kills bacteria, especially anaerobes. ## Halogens - Include Iodine, iodophores (Providine iodine), chlorine, chlorophores. - **Iodine** - Rapidly acting broad spectrum (bacteria, fungi, virus, some spores) - **MOA:** Acts by iodinating proteins and oxidizing microbial protoplasm (cellular components) leading to microbial death. - Uses: cuts, degerming skin before surgery, wound cleaning, minor burns - Adverse effect: cause burns & blisters. ## Iodophores - Known as povidone iodine - Non toxic, non staining prolonged action - **Uses:** boils, furunculosis, burns, ulcers, tinea, surgical scrub, disinfecting surgical instruments, non specific vaginitis, cleansing wounds, and infected dermatitis. - Kills bacteria, viruses, fungi, and protozoa. - **MOA:** Penetrates cell walls of microorganisms and interferes with protein structure, leading to cell death. ## Chlorine - Potent germicide. - Kills pathogens in 30 seconds. - Used to disinfect urban water supplies. - **MOA:** Chlorine releases hypochlorous acid, which oxidizes and disrupts the cellular components of microorganisms. ## Cholorophores - Chlorinated lime (bleaching powder) - Obtained by action of chlorine on lime. - Used to disinfect drinking water. - Sodium hypochlorite - Powerful disinfectant used in dairies for milk cans. - Too irritant to be used as antiseptic. - Root canal therapy in dentistry. ## Biguanides - **Chlorhexidine: (Savlon)** - Non irritant, more active against gram +ve bacteria. - Used in for surgical scrub, neonatal bath, mouth wash & general skin antiseptic. - Most widely used antiseptic in dentistry 0.12-0.2% oral rinse or 0.5-1% tooth paste. - **MOA:** Acts by disrupting bacterial cell membrane & denaturation of bacterial proteins. ## Quaternary Ammonium Antiseptics (Cetrimide) - Detergents, kills bacteria, fungi & viruses - Efficiently remove dirt and grease. - Widely used as antiseptics & disinfectants for surgical instruments, gloves etc - Combined with chlorhexidine (savlon) - **MOA:** Act by altering permeability of cell membrane. - Other examples include Benzalkonium chloride, Cetylpyridinium chloride. - ## Soaps - Anionic detergents. - Weak antiseptics with cleansing action. - Washing with soap and warm water one of the most effective methods of preventing disease transmission. - Affect only Gm+ bacteria. ## Alcohols - Eg Ethanol, Isopropyl alcohol - Ethanol - Cleansing agent at 40-90% conc - **MOA:** Act by precipitating bacterial proteins (coagulation of proteins), disrupting cell membranes, and causing cell lysis. - Irritant, should not be applied on mucous membrane, ulcers, open wounds. - Broad-spectrum activity against Gram + and Gram- bacteria, fungi, and viruses. - Commonly used for skin antisepsis before injections, venipuncture, or surgery. ## Aldehydes (Formaldehyde) - Used for fumigation. - 37% aqueous solution called formalin. - Used for preserving dead tissues. - Use as antiseptic restricted due to bad odour & irritation. - Glutaraldehyde is a better sterilizing agent. - **MOA:** Protoplasmic poison, denaturates proteins. ## Acids - **Boric Acid** - Weak antiseptic, bacteriostatic. - Used for mouth wash, irrigation eyes, glossitis. - Adverse effect: vomiting, abdominal pain on systemic absorption. - **Acetic Acid** - Effective against a wide range of microorganisms, including bacteria (Gram -ve eg pseudomonas aeruginosa), fungi, and even some viruses - It is used in both clinical wound care and some household disinfectants - **MOA:** Disrupting the lipid membranes of bacteria and fungi. - Penetrates the cell wall and interferes with cellular metabolism, leading to cell death. ## Metallic Salts - Example: Silver nitrate, Mercuric chloride, Zinc oxide - **MOA:** Heavy metals act by binding to and inactivating proteins, disrupting enzyme functions, and causing cell death. - **Spectrum**: Broad-spectrum antimicrobial activity. - **Silver Compounds** - Silver sulphadiazine is active against pseudomonas seen in burns patient. - Silver nitrate highly active against gonococci, burns, neonatal conjunctivitis. - **Zinc Salts** - Mild antiseptic, used as eye wash, ear drops. - Zinc oxide is used in wound healing ointments and skin protectants. ## Dyes - **Gentian violet** - Active against bacteria (gram + ve), fungi. - Used on chronic ulcers, furunculosis, bed sores, ring worms. - **Acriflavine** - Active against gram +ve bacteria & gonococci. - Suitable for chronic ulcers & wounds. - Do not retard healing, non irritant. ## Chlorinated Aromatic Compound - **Triclocarban** - Chlorine content contributes to its antimicrobial properties. - Effective against Gram-positive bacteria eg Staphylococcus aureus - Limited activity against gram -ve bacteria and fungi - **MOA:** Interfering with bacterial cell processes. - Used in antibacteria soaps, hand sanitizers, and deodorants. - Its antimicrobial action helps to prevent body odor and skin infections. ## Pharmacokinetic Properties | Structure | Terbinafine | Itraconazole | Fluconazole | Griseofulvin | |--------------|-------------------|-------------------|-------------------|-----------------| | Formulation | Allylamine | Triazole | Triazole | Spiro-benzo(b)furan | | | Tablet, oral granules | Capsule, oral suspension, IV, tablet | Tablet, oral suspension, IV | Tablet, oral suspension| | Peak level post-dosing | 2 hours | 3-5 hours | 1-2 hours | 2-6 hours | | Half-life | 36 hours (27-30 hours - granules) | 21 h (37-40 hours - solution) | 30 hours | 9-21 hours | | Percentage bioavailability | 40% - Tablets | 55% | >90% | 25-70% | | | 36% - 64% - granules | | | | | Impact of food | Tablets not affected by food; granules to be sprinkled on food | Capsules: Highest levels: full meal or fasted with cola beverage. suspension: take without food | Not affected by food intake | Absorption is significantly enhanced by administration with or after a fatty meal | | Protein-binding | >99% | 99.8% | 11%-12% | 84% |