Antimicrobials

Antimicrobial is the umbrella term the chapter uses for any drug that inhibits or kills microbial cells -- a category spanning bacteria, fungi and viruses. Under that umbrella, three more specific roles are distinguished by where each type of agent is used and how selectively it acts. Disinfectants are non-selective antimicrobials: they kill a wide range of microorganisms indiscriminately, including bacteria, and for that reason are applied only to non-living surfaces -- floors, laboratory or medical instruments, sanitary fittings, and similar surfaces -- rather than to the body. Antiseptics, by contrast, are formulated to be used directly on the surface of living tissue, specifically in situations where the risk of infection is high, such as during surgery or when treating an open wound; being applied to living tissue is what makes their selectivity and lower tissue-toxicity important in a way that is not required of a disinfectant. Antibiotics are a third, still more targeted type of antimicrobial, designed specifically to act again …