ABX

ABx is a commonly used abbreviation for antibiotics in medical documentation, prescription labeling, and biomedical literature. Antibiotics are a diverse group of medicines that target bacteria, and they do not treat viral infections. The term ABx is used primarily in clinical notes and electronic health records as a shorthand for an antibiotic agent or therapy, though it is not specific to a single drug.

Antibiotics work through various mechanisms, including inhibition of cell wall synthesis, protein synthesis, nucleic acid synthesis, or metabolic pathways. They may be bactericidal, killing bacteria, or bacteriostatic, inhibiting growth to allow the immune system to clear the infection. Agents are classified by their spectrum of activity, chemical structure, and mode of action. Major classes include beta-lactams (penicillins, cephalosporins), macrolides, tetracyclines, fluoroquinolones, aminoglycosides, and sulfonamides.

In practice, antibiotic selection depends on the suspected pathogen, site of infection, patient factors, and local resistance patterns. Dosing and duration are guided by guidelines and culture results when available. Antimicrobial stewardship emphasizes using the narrowest effective spectrum for the shortest appropriate duration to reduce resistance and adverse effects.

Antibiotic resistance poses a major public health challenge, driven by overuse and inappropriate prescribing. Mechanisms include enzyme production that destroys drugs, changes to drug targets, and increased efflux from bacterial cells. Side effects range from mild gastrointestinal upset to severe allergic reactions and Clostridioides difficile infection.

Historically, antibiotics transformed medicine after the discovery of penicillin, with ongoing development of new agents and alternative therapies. See also antimicrobial resistance and antimicrobial stewardship.