Antiseptics and Disinfectants
Antiseptics and disinfectants are chemical agents that inhibit or destroy microorganisms.
- Antiseptics: Applied to living tissues (e.g., skin, mucous membranes)
- Disinfectants: Used on non-living surfaces to sterilize and reduce microbial load
Classification
- 1. Alcohols:
- Ethanol
- Isopropanol
- 2. Halogens:
- Iodine solutions
- Chlorine compounds
- 3. Oxidizing Agents:
- Hydrogen peroxide
- Benzoyl peroxide
- 4. Phenolic Compounds:
- Chlorhexidine
- Triclosan
Pharmacodynamics
- Alcohols: Disrupt cell membranes + denature proteins → cell lysis and death Broad-spectrum: active against bacteria, fungi, viruses
- Halogens (Iodine/Chlorine): Oxidize proteins and nucleic acids → microbial inactivation Effective against bacteria, fungi, viruses, and some spores
- Oxidizing Agents: Produce free radicals → damage lipids, proteins, and DNA Fast-acting and potent (e.g., hydrogen peroxide → H₂O + O₂ via catalase)
- Phenolic Compounds:
Disrupt cell walls, precipitate proteins → antimicrobial effect
- Chlorhexidine: Broad-spectrum; pre-op and oral rinse use
- Triclosan: Common in soaps and dental products
Side Effects
- Ethanol:
- Common: Nausea, dizziness, headache
- Rare: Liver damage, pancreatitis, neuropathy
- Iodine:
- Common: Skin irritation, staining
- Rare: Allergic reactions, thyroid dysfunction
- Chlorine Compounds:
- Common: Eye/skin irritation, respiratory distress
- Rare: Chlorine gas poisoning, chemical burns
- Hydrogen Peroxide:
- Common: Mild irritation, skin bleaching
- Rare: Severe burns, gas embolism (if misused)