Chapter 10 : Antiseptics and Disinfectants

Abstract:

Antiseptics and disinfectants, like antibiotics, are chemicals that kill or inhibit the growth of bacteria and other microorganisms. Most antiseptics and disinfectants are bactericidal. Most are also effective against other types of disease-causing microbes such as viruses, fungi, and protozoa. This broad coverage has a drawback, however, because the chemicals used as antiseptics and disinfectants are too toxic for internal use in humans. Antiseptics and disinfectants tend to attack multiple targets in microbes. For example, iodine and chlorine are strong oxidants that inactivate many microbial proteins. Hydrogen peroxide is also a strong oxidant that inactivates many microbial targets. Antiseptics and disinfectants do best against actively replicating microorganisms. The discovery that resistance to antiseptics and disinfectants can develop is disturbing because disinfectants and antiseptics are a vital line of defense against microbial infections. Triclosan has proved to be the first exception to that general rule. Although its action is as general as that of any other antiseptic or disinfectant, resistance to triclosan involves a specific enzyme. Protecting antiseptics and disinfectants from abuse is important to preserve these important compounds for cases in which they are critically needed. The public seems to be awakening to the importance of protecting antibiotics by preventing their overuse. Unfortunately, awareness of the dangerous path we are treading as we overuse antiseptics and disinfectants has not reached the same level of public consciousness and concern.