ABSTRACT
Antibiotics are drugs with therapeutic activity against living organisms, the term usually reserved for drugs active against bacteria. They are commonly described as either bacteriostatic or bactericidal, depending on whether, at any given concentration, they inhibit or kill the bacteria. This chapter discusses the antibiotics most commonly used in dermatology, including broad- and narrow-spectrum drugs. One of the problems dominating antibiotic usage is the rising prevalence of resistance among bacteria, either because of intrinsic drug resistance or acquired resistance due to mutation or transfer of plasmid-based resistance genes. Penicillins are bactericidal because they inhibit bacterial cell wall synthesis leading to death of the microorganism. Monitoring is not necessary unless the patient is on a prolonged course of flucloxacillin or is known to have renal or hepatic impairment. Penicillins are not known to be harmful in lactation. Trace amounts of penicillins are excreted in human breast milk.
